# Optical Forums > Ophthalmic Optics >  Contact Lens Education

## chip anderson

I had hoped to start a whole contact lens forum, but Steve feels this would not have enough interest.  So I plan to start a string which will be to impart general knowledge of contact lenses.  I seem to know quite a lot about rigid lenses an don't really think soft contact lenses require much intellect so I will to try to place a few posts each week starting with the more basic things of rigid contacts working to some of the more intricate ones.  Will be happy to respond to anything anyone has to ask or say on the subject.

Chip Anderson, FCLSA

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## stephanie

Great idea Chip!! I for one am interested. I found a lot of the information on this board helped me with the ABO and am hoping it will help with the NCLE. Did you do this just for me?? I barely know anything about them except what I am currently learning. 
Have a great day!! 
Steph

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## Darryl Meister

Sounds like a great idea, Chip. Maybe we should do the same for spectacle lenses.

Best regards,
Darryl

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## Sara

Dear Uncle Chip,
Your ideas is fantastic!! PLease go ahead I for one would study your tread.
Thanks You.
Sara

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## Maria

Of course, in Nairobi, uncle means 'old dude'.... :D Just kidding Chip. You do give off that avuncluar vibe, though.
Tip to Sara - never ever mention ethics in dispensing, particulary not in relation to Drs filling their own prescriptions. You'll never shut him up  :) 
Seriously, it's nice to have input from a new country, and I'm a student too, so we can ask the masters questions together.

Maria

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## chip anderson

O.K. here it is, the first posting.  I suppose I will start with what you should do when dispensing rigid contact lens to the patient.  Teach the patient to wash his hands with a soap that does not contain oil, I always recommend: Ivory Bar for both rigid and soft contacts as it contains only soap, and since this isn't taught in school any more, tell the patient the purpose of soap is to mix oil and water.  There by removing the oil and dirt with rinsing.

The patient rub the lens manually with the thumb and forefinger for one full minute with wetting solution or conditioning solution as the advertising men may refer to it.  Rinse the lens by dipping it in a glass of water.  When I had been in the business about six weeks I and we had only PMMA then, I found that polishing lenses would be a major part of my life. I spent five years interviewing five thousand patients on handleling and found that 99 out of 100 who handled their lenses over the sink (even with a towel over it) had scratched lenses. This was amazing because 80% of these will tell you "But I never drop one."

Stay with the patient an teach him to insert and remove his lenses (without the use of any anesthetics. Have him do it in your presence until you feel he can, do not allow him to take the lenses home with him if you don't think he can do this.  Do not allow anyone else to do this for him except in the cases of the very young and the senile.  If someone else will do this, the patient will never learn to  do it by himself.

Teach the patient to clean, disinfect and store his lenses.  No matter what the instructions say, tell the patient to scrub his case out weekly with a tooth brush and Johnson's Baby Shampoo.   I know that the solution manufacturers want daily replacement of solution, I don't care too much about this but I want all dirt and cultures scrubbed out weekly.

enough for now, Chip

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## Maria

We get taught that they should use CL solution, instead of baby shampoo, for cleaning the case. Is that worse, better of the same?
Maria
PS You are a bit like Master Yoda, with a little Mr Miaggi thrown in.  :) Squish! Just like grape.

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## Maria

Also we get told that lenses should never touch ordinary water, because of all the crap that's in it. Is this what you think? Or do you think it's ok?

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## chip anderson

As to water (in regard to rigid lenses at least), I think it's just fine for rinsing lenses.  I do know a lot of experts and biochemist opthalmologist who disagree with me.  However that same old tapwater is exposed directly to the eye in the shower and if the bugs gonna get you.  It's gonna get you.  Now as to growing bugs in the case, I take this very seriously and think Johnson's Baby shampoo is much better than contact lens solution for cleaning the case.  This upsets Johnson's but who cares?

Now as to a real source of eye infection: Wetting the lens with saliva.  This can be cured in most cases by asking the patient to hold out his hand and close his eyes.  Put an artificial eye (preferably in his color) in it and tell him this is what he is taking a chance on.   You can even tell him he never had an "emergency" worth taking a chance on that.

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## chip anderson

My insight on Solutions: 
Rigid PMMA lenses.  Soaking solutions should be strictly a soaking or a combination soaking/cleaning solution.  Wetting/soaking solutions should not be used.  The gum~up the lenses and case.  I used to have two compeditors, one recommended dry storage the other used the only combination soaking/wetting solution on the market at the time.  Both had patients who ended up in my office and were "cured" when I buffed the encrusted solutions or dried on proteins off the lenses.  The encrustations looked so similar that in RGP Lenses I often think a great many of our troubles are caused by the fact that combination wetting/soaking solutions are all that is available for them.

Also I shudder to think how many unsuspecting souls have been sold new lenses when all the old ones needed was the deposts removed (mostly from the posterior surface).

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## chip anderson

Rigid Lens Inspection

This is why you are entitled to a mark~up on rigid lenses. Regardless of what the FDA says or feels on this subject this is how you earn your salt as an optician/contact lens technician. Those who feel that they can say: "I trust my laboratory, will find that they are very wrong once they institute these practices.

1) Check the central posterior (base) curve of every lens. This may be done with a keratometer or a radiuscope or several automated devises. Tolerances should be no more than .02 mm (1/8 diopter) and no, this does not double for torics or bifocals.

2) Check the power (focal length) with a lensometer or automated devise. This should be withing 1/4 diopter+or- and should not be + on ½ of a pair and - on the other half.

3) The diameter should be checked with a measuring magnifier or a sliding diameter gauge. Tolerance should be .10 mm or less.

4) Check the thickness. This may be done with a thickness gauge or a lens clock. To use a lens clock place the lens on a flat surface and place the lens clock with the movable pin on the lens, it reads in 1 mm. increments.

5) Check the edge design with a measuring magnifier, this may also be profiled on some lensometers by holding the lens on the mirror(movable) at an angle 90 degrees from that for power and focusing near plano.

6) Check the surface quality, with a measuring magnifier and/or a radiuscope. Tolerance on lathe marks, casting marks, tool marks, 

7) Check the optics: Should be done with both the lensometer and by holding lens at arm's length and viewing a flourescent tube through the lens. The lens should be moved and rotated, you will be amazed at the waves, rings, and other aberrations that appear with this technique.

8) Check the color.

9) There is not a whole lot you can do about checking the material, there are specific gravity tests for this but they are not a practical office procedure.

If you can't or won't or don't have the equipment to do all of the above, the patient would be served equally well by purchasing lenses from Linda Carter, who can't tell one lens from another. If you do all of the above even on replacements, you can truly say you have earned your salt. Your lab won't love you but they will learn to respect you.

Ole Chip

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## stephanie

Ok I have a couple of questions here that came right out of my book. Bear in mind that I do know the answer as I have the answer key. What I don't know is why? 

1.  A contact lens has a base curve of 7.50mm. Its posterior peripheral curve would most likely be:
A)  7.45mm
B)  42.50 D
C)  7.35 mm
D)  30.00 D

2.  Of the curves listed which indicates the flattest base curve?

A)  7.50mm
B)  37.50 D
C)  8.60 mm
D)  49.00 D
Like I said I do know what the answer is but I do not understand why. 
Thanks!!
Steph

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## chip anderson

Stephanie:
The answers to your questions are:
1=D    2=B
The reasons why are:
Question 1  
7.45(45.37+or-) and 7.35(46.00-) are shorter in radius than the base (central posterior) curve.  Any grinding of these curves to the base would touch in the center.  42.50(7.94 mm) is rather close to 45.00(7.50) and would not provide much relief at the periphery of the lens.  In fact if ground  into a 7.50 radius it would soon grind very wide and approach the center (trust me on this my first job in the contact lens industry was cutting an polishing base curves).  Now 30:00 Diopters has a radius of about 10.0 mm (I think) and would grind into the periphery quite well and provide some relief for tear circulation and limbral clearance during movement.  I would not chose this a peripheral curve on a lens of this radius myself, but it obviously would grind into the periphery.

Question 2
37.50 D= 9.00 mm.
Try to think of any lens surface as having: less power as it grows longer in radius.  This is true no matter what the lens is for or what it is made of.

Now as to Base curve charts.  Do you have a copy of Contact Lens Quarterly?  If you do at the end of the "RGP/PMMA National Distributors" and before the solutions you will find a very good chart in every issue.  Tear one out and put it with your reference materials.   There is also a vertex (unfortunately a front vertex) chart on the same page.  If you don't have a quarterly, let me know and I will E.Mail you a chart.

Chip

Chip

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## stephanie

Ah Chip!! I believe me book has some wrong answers. I have for the answers both as being B. Hmmmm... interesting. Well at least now I know when I question things it is usually with good reason. I don't have a chart as I have never had a reason to get the contact lens books. Thanks for all your help this has cleared some things up. At least til I get stuck again. Lord knows it is likely to happen any minute. 
Thanks Again!
Steph"I am gonna end up in a rubber room before I am finished with cls."D

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## JJ

a

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## JJ

Hi everyone, new to this

i have read valuable information on optiboard.  i have a cls question

the other day a guy came in for cls

rx  +5.25 -0.75  OU

corneal cyl 0.75D

did not want GPs or torics, wants for occasional use.  
heres the problem  va with glasses  20/20
sphere cls SE 20/40-3
diagnostic mor +0.75 kinda helped.  
I just to see what power would give him 20/20, he needed +6.25 (since lenses go by .50 after 6.00... 6.00 va 20/20-3, 6.50 va 20/20-1)

since this is a huge jump in power i have a call into the dr and am awaiting a reply as to what to do.  can someone shed some light on this for me.

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## chip anderson

You might try a thicker lens, this will sometimes mask some cylinder.  Also some aspheric lenses will "sometimes" help.  Otherwise tell him GP, toric or live with it.

This all asumes that the lenses fit and center of course.  If the lens is too steep, 
(Checked by taking over the lens K's) if they are not crisp, go flatter).

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## JJ

thanks chip i knew i could get some good info from you  
i was thinking of trying a thicker lens but my main concern was the cl having to be +6.50 when rx is +5.25-0.75.

keep up the good info

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## shanbaum

> Originally posted by JJ:
> _thanks chip i knew i could get some good info from you  
> i was thinking of trying a thicker lens but my main concern was the cl having to be +6.50 when rx is +5.25-0.75.
> 
> keep up the good info_


Well, there's the almost-half-diopter increase due to the vertex change...  Your +6.50 contact has the effective power of a +6.00 spectacle lens.  So, while there's a difference, it's not so humongous.  And I'm assuming his specs fit normally (around 13mm); do they?



[This message has been edited by shanbaum (edited 02-23-2001).]

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## Shwing

Actually, JJ e-mailed me with this question a few days ago.  I suggested that s/he post it to Optiboard, whereeveryone could get in on the answers.  I am glad to see JJ did!

Actually Mr. Shanbaum took the answer right out of my mouth...  And what was the vertex distance of the exam?

Shwing;-}

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## chip anderson

While vertex is a partial explanation for the additional plus required, I would still check for a base curve too steep and expect it or cylinder requirement to be the reason for the fuzzy vision after adding the plus for vertex.  And, while we are on the subject I have seen many, many hyperopes require much more plus than vertex would allow for after getting contacts.  This plus is often not needed until 3 days to two weeks after being fitted with contacts.  I think this is due to a latent hyperopia that shows itself after the patient relaxes whatever accommodation they may have.

Chip

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## Optom

Chip,
What do you understand by when you say latent hyperopia.
In your opinion when fitting RGP lenses more importance you give to lens diameter or base curve.
Checking on your views!

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## chip anderson

In response to your question, the base curve. 
This is a little like asking: "What size do you use?"   I give the lab all specifications, diameter, base curve/s power/s, peripheral curves, optical zones, thickness, flange power.  Anything applicable.  I have been in the contact lens industry since 1958 at all levels, chances are I have more experience/knowledge of the subject than the little girl at the right~up desk, probably more than the consultant.  And more importantly, I have the patient in hand the lab has never seen my patient.  

This does not mean that I will not seek out advise, but I try to make my own decisions good or bad and live and learn by my mistakes.

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## stephanie

You definately have more experience than this little girl at the desk. That is why I like to pester you to death with all my questions!! LOL!! I'll get all the info I can. Speaking of info. How can I order one of those cl books you spoke about? The doctor doesn't get that one and she would like to be able to get it too. Still studying don't know if it is getting me anywhere but I sure am trying like crazy. :) 
Have a great day!!
Steph

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## Optom

I would like to make little contribution
CLINICAL WISDOM FOR FITTING:
1)Lens Diameter is the No.1 fitting parameter for rigid lenses,rather than base curve.
2)Soft lenses are for today,hard lenses are for life.
3)There is no such thing as a one lens fits all
4)The perfect extended wear lens has not been invented.
And lid eversion is a neccessary part of examination on every after-care visits(You all probably know why).

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## chip anderson

Sabbir:   On your point #1, I think you are all wet.  But I will defend your right to say it.


Sab:  Wet Wrong!

[This message has been edited by chip anderson (edited 02-24-2001).]

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## Maria

Is being wet right or wrong? And how come they don't do an American to English dictionary, so I don't have to look stupid asking these questions.

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## Sara

Uncle Chip,
Wet in my part of world means a womaniser!
May be in China it means something different again.
Anyway,I also learn American slangs,great indeed.
Sara

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## chip anderson

In the U.S. "All wet" usually (and in this case) means wrong.  In fact now that I have pondered the matter, I don't think that there is a "most important consideration" in rigid lens fitting.  At least not before you start.  Of course if something is wrong, that becomes the most important part.  As to base curve vs. diameter they both make up 1/2 of the specification sagital depth and to have an imbalance of either would make them both wrong.

I think base curve, sagital depth, diameter, posterior optical zone, peripheral curve width/radii, bevel width radii, edge roll/shape, lenticular zone are all important an neglect of any can result in  a poor fit, poor comfort or be detrimental to long or short term corneal health.


Chip  (Hard to please) Anderson

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## Maria

> Originally posted by Sara:
> _Uncle Chip,
> Wet in my part of world means a womaniser!
> Sara_


Where I come from it means something too rude to mention here.  :)

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## Joann Raytar

> Originally posted by stephanie:
> _Ah Chip!! I believe me book has some wrong answers. I have for the answers both as being B. Hmmmm... interesting._


Steph,

Chip is right about the answers to your examples.  (45.00D =7.50mm)  Do you remember how a couple of us told you how to convert Base Curves to Diopters?

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## Joann Raytar

Contact Lens Master Chip:

Starting the thread was a good idea!  I mentioned in another post that I was returning to an independent shop; now I won't have to start a whole new thread when I come running to you for advice.  It is nice to see that you speak from experience not just a text book.  There is too little of that type of knowledge these days.

Jo

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## Joann Raytar

Chip:

We get alot of people, especially teenagers, who come in looking for non-Rx cosemetic lenses.  We also get alot of expired contact lens Rx's in.  Both will get into a shouting match and say they have gotten lenses in other cities without exams or fittings.  Short of tossing one of your glass eyes at them, how do you effectively deal with them; they kind of ignore the medical device speech?  I know you a good with words and I am looking for optical "fire and brimstone" here.

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## Maria

I know you addressed this to Chip, but with the teenagers I would try pointing out that no-one will fancy them (or whatever the US term is) when they are blind and their eyes are all starey and strange. Use the word 'disabled', as it has good psychological impact. Tell them that you couldn't care less if they go blind, but they're not doing it in your shop. Teenagers can relate to people who couldn't care less  :) And shout loudly, because your're older than them and you can.

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## Sara

In fitting of RGP lenses we are taught that lens diameter is important to obtain good centration,base curve is not mentioned.
Sara,
Optical Student(2nd year)

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## Sara

Uncle Chip,
Shabbir asked your view on importance of lens diameter versus base curve in relation to RGP fitting parameters.
You replied base curve.
Shabbir expressed his view that he considers diameter an important parameter in RGP fittings.
You answered him with he is all wet(LOL).
In your later tread posting you said"as to base curve vs diameter they both make up 1/2 of the specification sagital depth and to have an imbalance of either would make them both wrong"
This means in principal you agreed that diameter is important fitting parameter of RGP lenses.
So you were wrong in first place when you replied him that base curve is important parameter in RGP fitting.
You are confusing me uncle!

Your (dry) niece Sara

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## chip anderson

Sara:  I replied that the diameter being the most important concideration was wrong.  I did not say it was not important.  As you will note I don't think any parameter is unimportant, but if I were forced to say which was most important I would say the relationship of the base curve to the cornea, period.

You may have your parameter that you think is most important, you are entitled to this, as I am entitled to disagree.

[This message has been edited by chip anderson (edited 03-06-2001).]

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## Sara

Can someone please explain me in simple english
Cell Mitosis
Dk
Dk/t
I find it difficult to grasp from textbooks.
Sara

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## Sara

Uncle Chip,
You seem to be upset,that's the reason you not coming up with answers on questions posted in above tread.
Sara

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## shanbaum

> Originally posted by Sara:
> _Can someone please explain me in simple english
> Cell Mitosis
> Dk
> Dk/t
> I find it difficult to grasp from textbooks.
> Sara_


Cells reproduce in two ways, _mitosis_, in which case a cell divides in two so as to produce two cells, each with the same chromosomes as the parent; and _meiosis_, which results in two cells each having half the parents' chromosomes.

In simple English: mitosis is cell reproduction by division.

Dk is a measure of the ease with which oxygen can be dispersed (or "diffused")through a material.  Dk/L (and I suppose, DK/t) is similar; it's a measure of the actual transmission of oxygen through a material of a given thickness.

"D" is the "diffusion coefficient" and "k" is the "solubility coefficient".  Since I don't know how this measurement is actually done, I can't describe these.  But "diffusion" and "solubility" seem pretty descriptive.

Regarding Uncle Chip (thank you for that) and the diameter v. base curve issue:  I too would regard base curve as the more useful and critical fitting parameter.  You can't change the diameter nearly as much as you can the curve, and changing the curve has a more direct and predictable effect on the fit.

That said, I'd rather make bricks without straw than fit contact lenses.

[This message has been edited by shanbaum (edited 03-09-2001).]

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## Sara

Dear Uncle Shanbaum,
Thank you very much for your simple explaination.It was easy to understand.
Regarding Diameter VS Base curve in RGP fittings,I am going to write to my course tutor and association to find it out more.If Shabbir being an international lecturer on cornea & contact lenses does not know simple things like this,I will stop him from coming to Kenya to lecture on this subject.I know Shabbir because we are from same region,Kenya,Uganda and Tanzania makes East-Africa.I have attended couple of his recent presentations in Addis Ababa,Ethopia.He is research optometrist.Now time has come for him to make bricks.
Thanks again uncle.

Sara
optical student


[This message has been edited by Sara (edited 03-09-2001).]

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## chip anderson

Dearest Sara:  I was no upset, I had a page in an old "dictionary of Science" that Illustrates cell division in all four stages.  Didn't remember the names and particulars enough to send you a popped off answer.  Still haven't located the book, but If and when I will E.Mail it to you.

Chip

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## chip anderson

Finally getting back to this thread.

Methods of detecting corneal edema.
1) Observation in slit-lamp best seen with retro (light bounced off iris) illumination.
2) Central clearance (or sometimes more obscure areas) deminished under flourcein.
3) Changes in "K" readings from origional pre-fit condition.
4) Patient symtoms:  
1)Spectacles seem fuzzy on removal of contacts.
2) Photophobia (sunlight sensitivity) should not be persent in a "perfect fit" of any type contact.
3) Over wearing syndrome,  ( pain or discomfort sometime (30 min to several hours) after removal of lenses.

Recommendation:  Check all of the above and do something about it if significantly changed at any follow-up.  For the most part these things should not change at least on the short term.  It is true that as one goes from teenager to middle age+ the cornea is likely to move from with the rule to against the rule cylinder and average corneal radii are somewhat longer, but these should not be short term (less than one decade) changes.

Chip

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## Optom

Hi Sara,
Re-visiting this post.Did you get correct answer from your course tutor you were going to ask about silly but important arguement on RGP=Diam. Vs BC.
I always want to re-learn and want remain student througout my life though however qualified I am!
Your Uncle Chip is qualified & experienced contact lens technician as I have noticed from reading his postings.However,he is arguementative by nature.I appreciate his knowledge in optics.
Shanbaum has no intellect.All his postings I have read;either he pleases posters by putting little flavoured remarks,or copy- repeats the same.
If feel he is here to do postings to increase his optiboard points only.Honestly Sara,you despite being still student,you have better knowledge of optics than Shanbaum.

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## Sara

Dear Shabbir,
Yes, I did get correct answer from my tutor,but I don't like academic conflicts.Both of you are right,OK.
Thanks for the compliments too.
Thanks,
Sara

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## chip anderson

In the summer months we receive more warped and flattened, or even occasionally steepened (rigid) lenses than any other time of the year. Why: Because the UPS trucks are hotter and the labs are more pressed to turn lenses out in a hurry. It is our DUTY to catch these things before they make it to the patient. How are they detected? Method #1 With a radiuscope, If you get a toric pattern or any reading you don't expect, it's wrong. Method #2
This can be detected with a keratometer and a devise called a contacheck (W/J). Here you supend the lens in water and focus the kerotometer thorugh a 45 front surface degree mirror. How much is too much? 1/4 diopter.

Chip:drop:

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## chip anderson

Are You Providing Adequate Service?

I just had a new customer come to see me who had been purchasing contact lenses from my oldest competitor.  While the patient was there, I read the Rx, took K readings, examined the corneas in the slit~lamp, examined the presently worn contacts on the cornea in the slit~lamp, and examined the new lenses on the eye in  and took a history.  

I found that the patient had a lot of corneal vascularization to about two and a half millimeters into the cornea O.U.  The patient told me the name of the previous supplier and said: "They never did this at the other place.  After the first visit they never looked at them on my eye at all."  This deeply disturbed me as the competitor is my friend and has a fine reputation.

I don't know how things are where you are, but here the doctors that send me work assume that I am doing all of the above (although they also send work to the competitor) and they also assume that I will:

Look at the patient when difficulty is encountered, refer this patient to the doctor if the problem is not a mechanical one that I can fix, or if the source of the problem is not evident to me.

Refer the patient for annual exams to the doctor.

Examine the patient on a bi-annual basis if no problems are evident to the patient.  

Keep notes on my observations and improve fitting whenever indicated.

Examine each and every rigid lens for all specifications before dispensing or replacing to the patient.

Question:   If we do not provide these minimal services, what are we getting paid for?  

Chip

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## chip anderson

Jo:   

I am sorry that I did not notice this post directed to me, earlier.  Here I have the defense that:  "State law require that I have a 'contact lens precription" before I can dispense them or sell them."   This man not be the case in all locations.  But for me, I am CYA when it comes to giving the board of optometry (although I work almost entirely by M.D. Rx's) a reason to hang me.

I also explain that when the doctor writes this Rx he is saying that eye eye is healthy enough to wear contact lenses.  Many conditons that are not giving trouble can become very severe if aggravated with a contact lens.

Chip:)

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## mullo

Chip,

1) I agree with you, we should perform all of these functions before dispensing contact lenses to a patient. Even if the patient has seen someone else who is a great fitter for years and wants a duplication, I still do the required steps. My name is going on the fit from this time forward, so I will ensure it is correct. 

2) The Rx issue. I also refuse to dispense without an Rx and also a current one (2yrs old or newer where I'm from). I always tell the patient that the doctor will ensure their eye is healthy and that they are still candidates for contacts. I will then resort to #1 and do my own research and proceed if I find no problems.

Mullo    :Cool:

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## chip anderson

Sabbir:

One could if so inclined fit all eyes with a 7.0mm (rigid) lens or any eye with an 11.5 mm lens without changing anything but the base curve.   Like I said this all depends on the sagittal depth.  I know (knew) fitters who fit all thier lens quite small and many who fit all thier lenses quite large.  Now when one adds peripheral curve customizing (an almost lost art) the posiblilities are almost infinite and the diameter need to be the least of the conciderations.

In the words of Frank Sanning:  If you have an 8.5 trial set, you find yourself fitting a lot of 8.5's , if you have an 8.0 trial set you find yourself fitting a lot of  8.0's.

Another cool axiom to live by:  Quote at the Las Vegas Contact Lens Society meeting:  "If there were any real fitters here, they would be ordering uncuts."     Jim Tannehill of Hawaii who taught us how to fit torics.

 :Cool:  

Chip

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## chip anderson

RGP Lenses and occasionally PMMA lenses will develop a layer of deposits, that with time will build up a even with a concientious patient useing the best of care and cleaning.  Usually this can be seen with either a little magnifcation or staining of a lens viewed dry.  In some cases they deposits seem to be uniform and transpearent and are only evident when you see layers being removed by polishing.   I suspect this is why some practioners (along with a desire to kick sales along) feel that HGP's loose permeability.   The cure:  cleaning and polishing the lens,  yes you can charge for this and it's all profit without a wholesale bill.  The patient's will love you.

But the fine line is:  Don't polish lenses that do not need it.  Every polishing slightly (sometimes more than) distorts the lens no matter how expertly done.   You will abberate the lens slowly or rapidly,  so the less unnecessiary polishing, the better.

Chip.

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## Joann Raytar

Chip:

I have been told certain all-in-one solutions won't cause as much bleaching of colored contacts as other solutions will.  Is this truthful or just a sales pitch?

What solution do you tend to recommend most to new soft contact lens wearers?

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## chip anderson

Jo:   

I don't know.   I do know that certian manufacturers recommend that some soft lenses not be used with certian care regimens.   And do know that most colored lenses will fade.  Do not think that this is due to peroxide systems, though.  Suspect that most of the claims for most one~step sollutions are sales propaganda.

Have you noticed that Trans~air brown turns to Trans~air gray after a year?

I also know that if the solutions for all rigid lenses were separate wetting and soaking the lenses would not have most of the "deposits" they have.

Chip

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## Joann Raytar

Thanks Chip!  I agree with you:


> I also know that if the solutions for all rigid lenses were separate wetting and soaking the lenses would not have most of the "deposits" they have.

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## chip anderson

Many years ago an employer of mine who had a frustrating day as a hard contact lens fitting consultant came in and exclaimed: "Why can't they just get the concept that a lens is either too damn flat or too damn big?"

                                                     Jim Diprey

In this I think he conveyed more fitting knowledge than most of the industry has.

Chip

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## Tim Hunter

> *chip anderson said:* 
> The patient rub the lens manually with the thumb and forefinger for one full minute with wetting solution or conditioning solution as the advertising men may refer to it.  Rinse the lens by dipping it in a glass of water.


Chip interesting postings, I've only just found them. 

I'd just warn any UK students that the above statements and the suggestions regarding checking RGPs might cause them a problem in a UK exam.

You may not know that we have this lovely thing called new variant CJD or vCJD over in the UK (cows eat sheep with scrape, people eat cows with BSE, people get vCJD, possibly!). The Government here in its infinite wisdom has suggested that following a report from SEAC (advisory board on BSE/vCJD)there is a theoretical and unproven risk of transfer of the prion infective agent on trial contact lenses. So most practitioners in this country have gone to single use trial lenses or empirical ordering. To cut to the chase checking the RGP contact lenses could potentially contaminate them (especially if you've not sterilised your equipment with 2% sodium hypochlorite for at least one hour), as they are delivered sterile by the lab and whilst I wouldn't get too worked up about it, some examiners might.

T'other thing is we have this little bug called acanthoemeba which lives in tap water, slight risk of contamination even with RGP lenses, so we wouldn't recommend use of tap water at any point in the cleaning process unless it has been boiled and allowed to cool first.

Personally I advise against cleaning with thumb and forefinger and prefer resting the lens anterior surface down in the palm of your hand and cleaning with your little finger as I think this places less stree on the lens, but that's a personal opinion.

----------


## Tim Hunter

> *Tim Hunter said:* 
> Personally I advise against cleaning with thumb and forefinger and prefer resting the lens anterior surface down in the palm of your hand and cleaning with your little finger as I think this places less stree on the lens, but that's a personal opinion.


:hammer: 


Should have read ...places less stress..."
Excellent I'm failing the spelling bee and quoting my own words to correct them, I obviously need the next four days off, oh I have them!! 
:D

----------


## chip anderson

Tim: 

We have a few problems with our government thinking it has infinite wisdom too.   Don't think Acanthomeba is as much a problmem on rigid lenses and/or tap water as your government does.  However I do remember Joe Soper buying five gallon jugs of distilled water, having them taken to Baylor and tested, results: 3 of 5 had acanthomeba.  Also don't think Acanthomeba would be a problem if lens properly cleaned and cleared of all mostiure before delivery (but then I don't have a medical lab to research this).  But in 40+ years of CL practice I have never had a patient with acanthomeba infection, I think this is because I raise hell about wetting lenses in the mouth, have patients scrub the case out weekly with Johnson's Baby Shampoo, wash hands before handling, etc.

I also think that the 20-25% of RGP lenses that we receive off base or power or whatever specification is a more frequent risk(if not greater) than possible contamination from our office inpection.  Of course, if you government thinks it has infinite wisdom, they probably thind all labs have infinite accuracy and all lenses are accurate.

Chip

P.S.  What do you think the patients are  REALLY going to rinse them with anyway?  I am trying to get them away from the sink (as a source of scratches) which to me is the # 1 problem with rigid lenses.

----------


## Tim Hunter

Chip

agree it's unlikely all your patients will be scrupulous about not using tap water, but I give em my it's a small risk but you've only got one pair of eyes and they can at least make an informed decision.

Much easier for me because I'm based in a hospital and patients tend to be much better behaved in terms of solution compliance.

----------


## chip anderson

Tim:

Also concider that every patient is going to shower with tap water every day.  Many times a week tap water will enter the eye.  To my knowledge,  no one in the U.S. has ever gotten acanthomeba from this.  I think we are just being over protective.

Kind of like when Phyllis Rakow wrote that that patient should wash thier hands with anti-bacterial soap.  I wrote back to her that germ counts were the same whether the patient used plain soap or anti-bacterial soap.  Her answer: " People expect to see an anti-bacterial soap in a doctor's office."

My opinion,  chemicals in anti-bacterial soaps might slowly contaminate soft contacts and sting while the lens is being worn.  I recommed Ivory Soap in a bar (contains only soap).

I do think a certian amout of hygiene in the office and think the patients as a rule will be less concientious than we tell them to.  But I don't think the patient should act like they need to prepare for scrub surgery before puttin a contact lens on.

Chip

----------


## Joann Raytar

> *chip anderson said:* 
> Also concider that every patient is going to shower with tap water every day.  Many times a week tap water will enter the eye.  To my knowledge,  no one in the U.S. has ever gotten acanthomeba from this.


How resilliant do you figure acanthomeba is?  I know out here they treat the tap water with so much chlorine you can smell it, especially when the seasons change, I would think that nothing could live in that.

----------


## DerekHamilton

Greetings from the Lonestar state -- land of warped contacts!  I appreciate all of your comments on warpage.  I am interested in obtaining a Contacheck.  I have heard of people using a keratometer to measure base curves -- I never actually knew how it was done.  So thank you for the enlightment.  Since W/J doesn't exist anymore, does someone still manufacuter the Contacheck?  Or should I look on Ebay?  I am new out of optometry school and I don't have a lot of extra money -- or I would just buy a radiuscope.  I think that maybe a Contacheck would do the trick in the mean time.  I appreciate any comments!

Yours,
Derek Hamilton
Austin, Texas




> In the summer months we receive more warped and flattened, or even occasionally steepened (rigid) lenses than any other time of the year.  Why:  Because the UPS trucks are hotter and the labs are more pressed to turn lenses out in a hurry.  It is our DUTY to catch these things before they make it to the patient.   How are they detected?  Method #1 With a radiuscope, If you get a toric pattern or any reading you don't expect, it's wrong.   Method #2
> This can be detected with a keratometer and a devise called a contacheck (W/J).  Here you supend the lens in water and focus the kerotometer thorugh a 45 degree mirror.  How much is too much?  1/4 diopter.
> 
> Chip:drop:

----------


## Dave Nelson

Acanamoeba is a spore forming micro-organism that apparently has an affinity for soft contact lenses, but has caused keratitus in rigid lens wearers as well. In its spore form, the organism is extremely hardy, and can withstand boiling water for HOURS. It can also, if memory serves, survive a 3% H2O2 immersion for as long as 24 hours. 
Most keratometers, at least the one's I have seen, include a small plate and lens holder to measure BCs and warpage. It is on a vertical plane, but fulfills the primary requirment that the surface not being measured is fluid- neutralized. There are compensating charts available since the measurement of plus and minus surfaces are different. Derek, if you are planning on purchasing an autorefractor anyway, see if you can obtain one that includes a contact lens function as well, then you may have no need for a radiuscope, at least for a while. If not, the contacheck or similar device should suffice.

----------


## DerekHamilton

Dave -- you made my day.  I have a Canon autorefractor/keratometer.  At your advice, I pulled out the owner's manuel and discovered that, with an attachment, it will measure CL base curves.  I am really pleased about that because I would like to use more RGP's in my practice.  And of course, I have to be able to read base curves.  So -- thank you again.

Derek

----------


## Dave Nelson

Derek, glad to hear  you have the auto CL function on your auto refractor. If you have the same unit I have, you should also have the peripheral K function with eccentricity values graphed out. It is essentially a numeric topographer, and can be used for otho-K if such fitting interests you, and can also be used to graph cones, although a full colour topographer is more state-of-the-art for both functions. Good luck on your new practice.

----------


## npdr

> Finally getting back to this thread.
> 
> Methods of detecting corneal edema.
> 1) Observation in slit-lamp best seen with retro (light bounced off iris) illumination.
> 2) Central clearance (or sometimes more obscure areas) deminished under flourcein.
> 3) Changes in "K" readings from origional pre-fit condition.
> 4) Patient symtoms: 
> 1)Spectacles seem fuzzy on removal of contacts.
> 2) Photophobia (sunlight sensitivity) should not be persent in a "perfect fit" of any type contact.
> 3) Over wearing syndrome, ( pain or discomfort sometime (30 min to several hours) after removal of lenses.


Chip,

I'm curious.  The ide a of #1 was relevant in the days of PMMA and central corneal clouding wehr ethe edema is mor focal. In today's contact's, edema is more generalized over the whole cornea such that retroillumination, even direct observation may be difficult to detect stromal or epithelial edema.  In other words, even keratometry or topography might not pick it up.  

Of course, where edema is greater than 15% change you will see edema form the onset of endothelial folds. Punctate bullous keratopathy will occur when the cornea has increased by 25%.

In t hese cases, subtel changes can be detected with a pachymetry although I believe that it takes  50 nm of change before I would presume edema.

In chronic edema which is most consistent with soft lenses, limbal anoxia and their change in vasculature is revealing.

----------


## EyeFitWell

> and since this isn't taught in school any more, tell the patient the purpose of soap is to mix oil and water.


They taught that at my school!  (Graduated HS in 2002)
(This is really off-topic, but that is exactly why I think shampoo and conditioner in one doesn't make any sense.  You're most likely just going to wash out the conditioner and leave the oil in your hair.)
LOL...I guess I just had to reply to that because I was surprised to see someone else who knew exactly what soap is.

----------


## HarryChiling

no longer playing in this sand box

----------


## Dave Nelson

Kinda reminds me of the paper I submitted to the CLSA a few years back titled: Sam and Lars- evil twins? It was about the dependance on acronyms to remember simple optical principles. Left add, right subtract for toric axis compensation. Are you kidding me? As a learning tool, maybe, but it's irritating to see it published in trade journals and optometric journals. Someone who has done 5000 refractions needs to know "LARS?"

----------


## HarryChiling

no longer playing in this sand box

----------


## D-Boy

Hello all,

I am new to OptiBoard, and I am wondering if anyone out there can clue me in as to what I should be expected to know for the upcoming NCLE exam on Nov 19.  I am working with CLSA's Contact Lens Manual, as well as the CLSA's Test Review (200 sample questions w/answers), but I find that the Test Review questions are far easier than some of the concepts in the CL Manual.  

I spoke to the Test Manager at the NCLE, and she said that if the concept seemed too in-depth for a multiple choice exam where you cannot use a calculator...it is probably not covered in the examination.

Can anyone give me some pointers based on first-hand knowledge?  It would be very much appreciated.

----------


## OPTIDONN

Pay close attention to RGP fitting and modification.

----------


## Snitgirl

thanks Optidonn....

Are there contact lens history questions too? :hammer:

lol

----------


## chip anderson

Don't bother with history (for this exam anyway) most people making up the exams don't even know the history back to the '80's much less when the the early work was done from 1900~1960.   
Tests are more on how to keep inventory in a doctor's office than history.

----------


## OPTIDONN

> thanks Optidonn....
> 
> Are there contact lens history questions too? :hammer:
> 
> lol


Hey there are alot of people who are suprised by the amount of RGP questions asked and don't pay the amount of attention that they should to this...your mean :cry:

----------


## GOS_Queen

> Hello all,
> 
> I am new to OptiBoard, and I am wondering if anyone out there can clue me in as to what I should be expected to know for the upcoming NCLE exam on Nov 19. I am working with CLSA's Contact Lens Manual, as well as the CLSA's Test Review (200 sample questions w/answers), but I find that the Test Review questions are far easier than some of the concepts in the CL Manual. 
> 
> I spoke to the Test Manager at the NCLE, and she said that if the concept seemed too in-depth for a multiple choice exam where you cannot use a calculator...it is probably not covered in the examination.
> 
> Can anyone give me some pointers based on first-hand knowledge? It would be very much appreciated.


I just wanted to say Welcome to Optiboard :cheers:  Good luck on the test

----------


## Snitgirl

> Hey there are alot of people who are suprised by the amount of RGP questions asked and don't pay the amount of attention that they should to this...your mean



I'm mean?  Lol, its an actual question and I am not being sarcastic one bit...

----------


## D-Boy

Glad to see that there is life out there....
Thanks for the tips on studying lens design and modification....
The other areas of importance seem to be:
Anatomy/Physiology of the eye
Rx interpretation>type of lens (K readings vs Refraction)
Follow-up care and patient instruction...

Am I on the right track or what?  I have been ABO certified since 1997, and am fimally going to tackle the NCLE, and ultimately the AZ state exam.  I may be over-preparing (if there is such a thing), but I just want to make sure that I am covering my bases.

----------


## EyeFitWell

D-Boy, there is no such thing as over-preparing.  Even if it's not on the exam, it'll benefit your career!  Best of luck with both those exams!

----------


## rdcoach5

As a general rule, I add 1.5 mm for each of three radius tools to get the desired ski curves. In this example , 7.50 base curve, use 9.00, 10.50 and 12.00. The width of each is also specified, such as .25/9.00 .25/10.50 and .2/12.00. If your diameter was 9.5, yout optical zone is 8.1.
Bob Taylor

----------


## rdcoach5

> Ok I have a couple of questions here that came right out of my book. Bear in mind that I do know the answer as I have the answer key. What I don't know is why? 
> 
> 1.  A contact lens has a base curve of 7.50mm. Its posterior peripheral curve would most likely be:
> A)  7.45mm
> B)  42.50 D
> C)  7.35 mm
> D)  30.00 D
> 
> 2.  Of the curves listed which indicates the flattest base curve?
> ...


  My standard P.C. is 4.5 diop flatter than the Base Curve. A 7.50 B.C would have a 1st intermediate curve of 9.00 2nd int of 10.50 and peripheral curve of 12.00. the width of each is specified, such as .25/9.00  .25/10.50 and .2/12.00. If your diameter was 9.5 , the optic zone is 8.1

----------


## chip anderson

RDcoach:
What you have listed is 1.5 mm not 1.5 diopter radius changes.  mm is correct but done as written you will have a lot very small optical zones and not much edge lift.

----------


## rdcoach5

You are correct.

----------


## rdcoach5

Optical Training Institute has manuals that a youger co-worker used to pass her exam. That said, it doesn't really teach how to fit contacts-just how to pass the test.
                               Bob Taylor

----------


## EyeFitWell

> Jo: 
> 
> I am sorry that I did not notice this post directed to me, earlier. Here I have the defense that: "State law require that I have a 'contact lens precription" before I can dispense them or sell them." This man not be the case in all locations. But for me, I am CYA when it comes to giving the board of optometry (although I work almost entirely by M.D. Rx's) a reason to hang me.
> 
> I also explain that when the doctor writes this Rx he is saying that eye eye is healthy enough to wear contact lenses. Many conditons that are not giving trouble can become very severe if aggravated with a contact lens.
> 
> Chip:)


I also use the "it's the law" defense.  Sometimes they don't like that answer, and oh well.  We're not putting our license on the line for your convienence.  I've definately been fussed out more than once over this, but if Joe down the street doesn't need a prescription, then go see him and let him take the fall.

I recently was shopping in a beauty supply store and I noticed a young lady go up to the counter and inquire about color contacts.  I listened in, thinking I could hand her our card when she was told no.  Low and behold, out from behind the counter comes a box of colored contact trials, being sold for $25/ea.  I was amazed!  My manager was with me, and she elected to inform the powers that be.  I can't believe people are buying these things, and putting them in w/o any training, health check, etc.  

In general, though, I do try to stay away from the fire and brimstone.  If someone doesn't listen to the "it's the law" argument, I'll go so far as to say, "These laws really are in your best interest since contact lenses not used properly can permanently damage your eyesight."

----------


## D-Boy

Whohoo!

Not only did I pass that exam, but I scored a 90!
My only observation is that the study material available was totally current and reflected the test content to a "T"!

Does anyone know of any current ABO Prep material?  I just tutored 45 employees to prep for the test, and we had a 60% pass rate. The ones who didn't pass all scored in the 60's, so they were all very close to the goal.  Although optical concepts and theories have not changed, it seems that many of my students remarked that the questions on the exam were very different from the sample tests that we took...The sample questions came from a study guide first published in 1989, and was reprinted in 2001...without any updates...

I feel that the folks I teach would stand an even better chance of passing the ABO if they were exposed to sample questions that better reflect the true content and wording of the test...does anyone have any suggestions?  Has anyone looked at the study material offered through Morrison Media?  Here is the link: http://www.mo-media.com/noce/

I look forward to your feedback, and congrats to all others out there who passed their ABO and/or NCLE examinations!

----------


## HarryChiling

> Whohoo!
> 
> Not only did I pass that exam, but I scored a 90!
> My only observation is that the study material available was totally current and reflected the test content to a "T"!


Congrats :cheers:

----------


## eromitlab

wow... I didn't ever notice this thread existed until today. Chip, I am grateful that you are so generous with your knowledge... My doc is starting to move me from the spectacle end of things in the office to contacts/medical stuff, so I am having to learn a lot of new things (most of it on my own). I don't think I would ever be able to find the information you have given from anyone I work with now.

Thanks so much!! :idea:

----------


## eromitlab

Chip, I have a question for you.

My doc likes to have RGP wearers come in on a quarterly basis to have their lenses cleaned in an ultrasonic scrubber. Is this a good or bad thing for the lenses? I can see why it might be good for them, as the scrubbers work great in other applications where stubborn 'dirt' can be removed easily, but, are there any negative effects on the lenses?

He's also been real hot on having plasma treatments added lately, what are your thoughts on having lenses treated this way?

Thanks in advance!!

----------


## HarryChiling

I know that in an ultrasonic cleaner sometimes heat is generated that can cause slight warps in the lens, never done it so I don't know if this is an issue.  The best cleaning method is to polish the back side in my opinion.

----------


## chip anderson

I have all (Or at least tell them to do so) come in for check-up every six-months.  I check for deposits, if found, I buff both front and back lightly or as much as needed.  RGP's are bad about collecting a film of deposits that  can change the fit sometimes to the extent of locking the lens in place as bad as a keratoconnus lens fit way too snugly.  Often you will notice color "changes) blue will look gray and after buffing will return to blue.   Check closely after polishing for partial removal of deposits and aberration of optics.

Make sure patient is using daily cleaner and rubbing (even with no rub regimens) as well as using enzymatic cleaner weekly (they won't be).  Avoid the use of "one step" regimens.  

As to sonic cleaner for this, I have known other "experts" who recommend it highly, even went to course in Fla. with mfgs of such things that had bottles and polishes to be use in same.  Myself I have not seen any benefits from using sonic cleaners for deposit removal (I have two units but do not use them for this purpose).

Chip

----------


## eromitlab

thanks, Harry and Chip for your input. My other question, what solutions do you reccomend using? We only use Boston Simplus right now, mainly because of the lab sending the kits with all of the XO material lenses doc fits. Chip, I see that you have a problem with these as they tend to gum up the cases and leave deposits (I've noticed this since I started reading the thread). I would like to reccomend a possible alternative to doc, but I'm unsure as to what might be better.

----------


## HarryChiling

The simplus is a one step solution, which works well with soft replacement lenses, because you are replaceing them before the lens builds up any significant amount of protein.  With RGP's the lens is not disposed, so in my opinion I don't think that the one steps is a option for RGP's.  I would recommend going with the boston original or advanced formulas.  Tried and true.

----------


## chip anderson

When Boston Advance came out (origionally labeled to be for flourosilicon acrilate lenses as opposed to silicont acrilate polymers, which B&L seems to no longer remember haveing said) 80% of our patients prefered Boston origional.   80% of our patients still prefer Boston Origional for both types of lenses.    Of those that don't do well with same.   Many practioners tell me that me that their patients are too stupid for more than one solution (With my sarcastic nature, this translates to me: "I'm too lazy to teach them anything.")
For those patients who do not seem to like same we try whatever other solutions are available until we find one that the patient is happy with, always insisting on manual cleaning.

Chip

----------


## HarryChiling

Chip, what's your opinion on the simplus?

----------


## HarryChiling

Using a topographic map record the axis and the measure off center that the cone lies, *Ksteep*; then record the K reading 180 degrees or opposite the same measure from center, *K**flat*.  Now with these two readings you can use the mean K reading as the initial base curve to order and work from there.

*Kmean = (Kflat + Ksteep) / 2*

To determine the minumum diameter, use the measure from center that the cone lies and double it, this gives you a circle that the center of the cone lies on.  You can add 3mm to it as a rule of thumb for your edge design and centration.

If the cone lies in the center of the map use the *Kmean* as the base curve and for the diameter measure how far from the center of the cone or map to the first Kmean reading, now double this figur and add 3mm to it for your edge design and peripheral curves.

Of course this is only the intial diagnostic lens.  If the lens has too much saggital depth then you should flatten it if it rides too low increase the diameter, if it fits too flat steepen the base curve.

I just didn't want to let such a great thread die, and someone earlier mentioned about their doctor not letting them fit lenses, so heres some info.

----------


## chip anderson

Harry:  
Simplus and all combination solutions from my personal observations of many hundreds of patients.  The lenses and the case become gummy in a short period time.  Simplus just doesn't provide a good cleaning.
From what I have been told the only reasons for combination solutions are:
"My patients are too dumb to use three solutions." Translation: I am too lazy to teach them.
"My patients won't take the time." Translation: Such patient's don't deserve contacts.
I actually found that about 80% of our patients actually found on thier own that Boston Advance was not as effective as Boston Origional.  Very few find Simplus to be effective, those that do are ususally very rich, spoiled and second generation Ole Miss.

Chip

----------


## HarryChiling

Thanks for the reply, we have been giving out the simplus, but most of our patients are still using their cleaners from their old solutions.  Between the boston orginal and the advanced formula it's 50/50 some patients like the advanced better and some patients prefer to stick to the original and it's usually build up that causes patient to want to stay with the original.

I have never liked the idea of a one step for a RGP, again it works OK with soft lenses because they are disposable, but even in conventional soft lenses they don't work very well.

----------


## rdcoach5

Many years ago I attended a seminar that recommended using a peroxide solution such as Clear Care to remove residual abrasives left from cleaners like Boston. It also removes residual polish from contact lens polishing, as well as hand lotion . Simply rub the lens with the peroxide solution and rinse with water. It should feel squeaky clean. Since it disinfects quickly, I always rub my finger with the peroxide solution before each contact lens class. It cleans those old contact lens cases as well.
     Bob Taylor

----------


## HarryChiling

> It cleans those old contact lens cases as well.


I still haven't figured out the obsession with keeping those old dirty cases, I give people new cases and they still don't use them. :hammer:

----------


## chip anderson

I'm not sure peroxide cleans anything.  It bleaches things and kills germs.  But I don't know that it removes dirt.  Or mixes oil with water.

Chip

----------


## rdcoach5

Used to be every time I polished  contacts, pt.s would complain of stinging. Not after I started using peroxide to clean off the residual cleaner. It also removes those stubborn greasy lotions that don't come off with plain hand washing.simply rub the index, (or whichever handles the contact lens} with peroxide in the palm of your hand. Then rub off with water.Now you can rub the wetting solution into the lens and insert. It works for the real greasy stuff like Oil of Olay. Next you can try popcorn salt mixed with saline to create a paste that removes jelly bumps. Another old trick that absolutely works but is not needed much in this disposable age.
 Bob Taylor

----------


## chip anderson

Make real sure you rinse all the peroxide off the lenses and your hands or the patient will _really_ complain about stinging.

----------


## HarryChiling

> Make real sure you rinse all the peroxide off the lenses and your hands or the patient will _really_ complain about stinging.


I gotta tell you we ran back into the CL room once because we heard the most god aweful scream and sure enough a lady had tipped back a bottle of clear care in her eye.  For the life of me I couldn't figure out why she would do that, she had to open a new box that was on the shelf and go at it.  Her resoning behind it was she thought she would try a new solution.

Her eyes were the prettiest shade of red and no makeup. :D

----------


## specs4you

I am so excited I found this section for C.L. discussions.  I am being kept away from anything to do with C.L. by the two offices I have worked at in the past 8 yrs.  In my review I brought this matter up as part of my job disappointments.  Seems any front desk person being hired with no training at all is set up to do our trainings and answer questions to the patients.  I hear the wrong answers and techniques being used all the time.  My Dr. replied that I was worth more to him out on the floor.

Is this some kind of cop out or backhanded compliment or what?

I thirst for C.L. knowledge.  This is a very small office and everything is old and boring.  No challenges and everyone is too afraid of any change to shake anything up around there.  I have been looking for a new job for a very long time .......

I walked by a poor person struggling to get their lens in that had been left alone by one of these untrained young people and offered a quick piece of advise and the person got the lens in immediately.  When they went in to the Dr. they commented on why did they have someone untrained teaching them and not me?  I got a severe talking to....not a thank you
for bailing the office out..or a way to go.....no I was in the wrong.
Is this par for offices out there in this profession?  Seems everytime I go the extra mile jealousy rears its ugly head.  I notice for men in our trade things are very different.  Any women out there dare to comment?

I will quietly be watching this forum  and taking notes to learn.

By the way, I passed the ABO exam with the Optical Training Institute's course.  The most frustrating part of that course was that it is not a training it is a test taking tool.  I found myself wanting more info on the shortcomings I had in the field and not having the books resources to learn the gaps in my training.  It is a good course if you get over the errors in a couple of their test answers and the spelling and typos in the written material.  Obviously whoever put it together was not an English major and it seems it was put together in a hurry and not really proofed.
They really needed to have a dummy like me just sit there and go thru it and point out the things that were senseless and made them look stupid.
Other than that I passed with a high score.  I know we wouldn't know our score but the board lost my test results and had to look it up via phone and told me that I scored almost a perfect score , so kudos to that course I guess in the end.

----------


## specs4you

But wait.....I need to proof my own letter...boy what a mess.  Please excuse...I am way into the wee hours of the morning..good night.  zzzzzzzzzzzz

----------


## rdcoach5

> Make real sure you rinse all the peroxide off the lenses and your hands or the patient will _really_ complain about stinging.



It rinses off easily and you can tell because it's squeaky clean.

----------


## HarryChiling

The term *Modulus* refers to the flexibility of the lens material. The higher the value the stiffer the lens. The stiffer lenses are easier to get in for the patient as they tend to keep their shape better, but often times can have adverse effects like poor movement, and lens awareness.

Just a tid bit to keep the thread going. :D

----------


## rdcoach5

It's supposed to be an improvement on the Softperm. Gas perm center bonded to a soft lens outer edge. Any experience?

----------


## chip anderson

Haven't used the Synergeyes but used some of it's predecessors. Good lens for irregular corneas and medium cylinder. Fairly expensive, poor durability, kept tearing at junction of rigid/soft to the points where patient's felt you were ripping them off or they couldn't afford. 

Also earlier name for modulus was "hoop strength".

----------


## rdcoach5

[quote=chip anderson;186948]Haven't used the Synergeyes but used some of it's predecessors. Good lens for irregular corneas and medium cylinder. Fairly expensive, poor durability, kept tearing at junction of rigid/soft to the points where patient's felt you were ripping them off or they couldn't afford. 

Also earlier name for modulus was "hoop strength".[/qu

The newer version is more durable. Early negatives are at least 2 weeks for power more than +4.00 or -7.00

----------


## dbracer

> Can someone please explain me in simple english
> Cell Mitosis
> Dk
> Dk/t
> I find it difficult to grasp from textbooks.
> Sara


In chemistry and physics a small letter is sometimes used to designate a constant. pH represents hydrogen (H) concentration (p).

In this case "k" is use to as a designation for "constant", in this case diffusion (D). So we have a (D)diffusion (k)constant.

Dk tells us how much gas gets through a contact lens material, that is any gases. 'Course in CL's the most important gas is oxygen. The higher the number, the more gas gets through. 

But this is of little value if the thickness is not known. Ta-Da ... enters Dk/t, which means diffusion constant per unit of thickness. This is the number usually addressed.

The number is actually a coefficient taken times 10 raised to the -11 (minus  eleven) power. This is a representation of micro-liters/second/cubic cm etc. etc. etc. It's a physics nightmare. It's relatively simple if you don't get caught-up in the details of _uL/sec/cc3/this/that etc_. 

The standard soft lens has a Dk/t of about 28 or so, i.e..... 28x10-11 (the last number should be a supra-script, not a sub-script). 

The Dk/t of PMMA is about "0" (ie 0x10-11, in other words zero). RGP's run regularly 30,60,90 and can go as high as 130 or so. But, the new silicon hydorgel soft CL's have Dk/t's to 175 and beyond. 

Respectfully, 
dbracer

----------


## HarryChiling

Cell Mitosis - Is the process of a cell splitting apart, replicating itself, cloning (probably shouldn't use this term in a biological process involving DNA, but you know what I mean).  The cell goes through many phase in the process which is often the confusing part.

InterphaseProphasePrometaphaseMetaphaseAnaphaseTelophaseCytokenisisSometimes you will also include interphase although technically it is not part of the cell division process.  The different phases are marked by characteristic changes in the cell.  Basically the cell starts by condensing the necleus, the poles move to the opposite ends, the necleus membrane dissolves,  the chromosomes line up, they split, they travel towards the poles, the new membranes form around each cell necleus, the cells break apart.

That last explanation is the nitty gritty in english version you asked for, my wife is a biology teacher and can probabl explain it in so much detail your brain would hurt, but when teaching her students she does sometimes start with a break down like the one I have layed out, but a bit more accurate.  Anyway you should get the drift, if not PM me and I will pass on any questions you might have.

dbracer - great explanation of Dk/t.  I liked the quick small letter explanation as well when defining the constant.

----------


## dbracer

> Cell Mitosis - Is the process of a cell splitting apart, replicating itself, cloning (probably shouldn't use this term in a biological process involving DNA, but you know what I mean).  The cell goes through many phase in the process which is often the confusing part.InterphaseProphasePrometaphaseMetaphaseAnaphaseTelophaseCytokenisisSometimes you will also include interphase although technically it is not part of the cell division process.  The different phases are marked by characteristic changes in the cell.  Basically the cell starts by condensing the necleus, the poles move to the opposite ends, the necleus membrane dissolves,  the chromosomes line up, they split, they travel towards the poles, the new membranes form around each cell necleus, the cells break apart.
> 
> That last explanation is the nitty gritty in english version you asked for, my wife is a biology teacher and can probabl explain it in so much detail your brain would hurt, but when teaching her students she does sometimes start with a break down like the one I have layed out, but a bit more accurate.  Anyway you should get the drift, if not PM me and I will pass on any questions you might have.
> 
> dbracer - great explanation of Dk/t.  I liked the quick small letter explanation as well when defining the constant.


HarryC,

Holly cow, your into this stuff heavily. My brain is already hurting. 

How 'bout this Meiosis = a child 
                    Mitosis = twins following the  original meosis

if I spelled it all correctly, and this is only true at the animal reproduction level. 

Respectfully,
dbracer

----------


## HarryChiling

> Holly cow, your into this stuff heavily. My brain is already hurting. 
> 
> How 'bout this Meiosis = a child 
> Mitosis = twins following the original meosis
> 
> if I spelled it all correctly, and this is only true at the animal reproduction level.


Great way of explaining the differences between the two.  Again my wife is a biology teacher (AP as well) so it's her version of shop talk.  If you thought that was impressive, you should see her surface a progressive lens and edge it.

----------


## dbracer

> Great way of explaining the differences between the two.  Again my wife is a biology teacher (AP as well) so it's her version of shop talk.  If you thought that was impressive, you should see her surface a progressive lens and edge it.


Your wife sounds wonderful. 

Would she like a job in a place where there is quickly expanding high tech industry, no smoke stack industry, rural area, two major universities, Pac-10 sports, concerts and shows (Copperfield, Ladysmith, Supreme Court Judges etc.), NIAA World Series, no stop lights, no elevators, no traffic jams, freshwater streams galore, finest backpacking mountains, 5 ski resorts with an 1.5 hours, bird hunting, fly fishing, big game hunting, 5 minutes to work on bad day, few miles from the finest wineries in US, no tornadoes, no hail storms, no torrential rain storms, most fertile agronomy land in the world, no mosquitoes, no chiggers, no forest fires, no hot summers, mild winters, archery ranges, trap shooting courses, 325 acre pro-golf course - just completing, tennis courts, highest ranked school district in the State of Washington, most national merit scholars from the high school in the Northwest, best GPA in student athletes, and scenic splendor that runs on like a British novel?

It's a piece of heaven that the Californians haven't found, yet.  The West fears Californication of their home areas. 

It's called The Palouse, and ah heck, Harry, you can tag along too!

Respectfully,
dbracer

----------


## dbracer

> I'm not sure peroxide cleans anything.  It bleaches things and kills germs.  But I don't know that it removes dirt.  Or mixes oil with water.
> 
> Chip


Your right as rain there Chip.  It's questionable if it even does a very good job as a germacide, if you look at its actual spectrum. And, for sure it is not an emulsifyer. The old isopropanol systems were much better at "killing." 

But, most H2O2 users have few problems. Go  figure. 

Occasionally they forget to oxidize it before sticking it in their eyes. Still, few are much worse for the wear once it heals up. 

Respectfully,
dbracer

----------


## HarryChiling

> Your wife sounds wonderful. 
> 
> Would she like a job in a place where there is quickly expanding high tech industry, no smoke stack industry, rural area, two major universities, Pac-10 sports, concerts and shows (Copperfield, Ladysmith, Supreme Court Judges etc.), NIAA World Series, no stop lights, no elevators, no traffic jams, freshwater streams galore, finest backpacking mountains, 5 ski resorts with an 1.5 hours, bird hunting, fly fishing, big game hunting, 5 minutes to work on bad day, few miles from the finest wineries in US, no tornadoes, no hail storms, no torrential rain storms, most fertile agronomy land in the world, no mosquitoes, no chiggers, no forest fires, no hot summers, mild winters, archery ranges, trap shooting courses, 325 acre pro-golf course - just completing, tennis courts, highest ranked school district in the State of Washington, most national merit scholars from the high school in the Northwest, best GPA in student athletes, and scenic splendor that runs on like a British novel?
> 
> It's a piece of heaven that the Californians haven't found, yet. The West fears Californication of their home areas. 
> 
> It's called The Palouse, and ah heck, Harry, you can tag along too!
> 
> Respectfully,
> dbracer


I can't convince her to move, I have had some great job offers that I can't take advatage of because she will not budge. Thanks for graciously letting me tag along though. :bbg:

----------


## chip anderson

Harry:  Get your pants back, give her a skirt and move.

----------


## HarryChiling

> Harry: Get your pants back, give her a skirt and move.


You dirty roten SOB, you callin me a pansy. :bbg:

----------


## dbracer

> You dirty roten SOB, you callin me a pansy. :bbg:


I'm stayin' outa this one. 

Ya both seem like likable guys to me.

dbracer

----------


## Fezz

> You dirty roten SOB, you callin me a pansy. :bbg:


Harry,

I think he basically told you to "Get your B@t*h buttocks in the kitchen and bake him a pie". (Gleefully stolen from the cartoon-South Park)



 :D:D:D:D:D:D

I could be wrong though.

----------


## HarryChiling

> Harry,
> 
> I think he basically told you to "Get your B@t*h buttocks in the kitchen and bake him a pie". (Gleefully stolen from the cartoon-South Park)


But I might get flour on my skirt. :D

----------


## HarryChiling

Are No-rub Multi Purpose Solutions (MPS) dead?  

According to:

Efficacy of multipupose solutions against acanthamoeba species, Contact Lens & Anterior Eye (28) 2005 169-175

Renu w/ MoistureLoc was the most effective at destroying acanthamoeba.  It had a comparison to the most comonly used solutions and you can see from the list that one by one they are started to be recalled, could this be the end for "No-Rub".

----------


## dbracer

> Are No-rub Multi Purpose Solutions (MPS) dead?  
> 
> According to:
> 
> Efficacy of multipupose solutions against acanthamoeba species, Contact Lens & Anterior Eye (28) 2005 169-175
> 
> Renu w/ MoistureLoc was the most effective at destroying acanthamoeba.  It had a comparison to the most comonly used solutions and you can see from the list that one by one they are started to be recalled, could this be the end for "No-Rub".


Harry,

So was there any similar data established in a similar format on Fungi?

It was interesting that the B&L spokesman actually studied his on solutions, concerning the _Fusarium_ thing, but he stayed mute on how the others stacked-up at least in the material I read.

I just never pursued further study own the matter. 

Any stuff on that?

Respectfully,
dbracer

----------


## HarryChiling

Contribution of regimen steps to disinfection of hydrophilic contact lenses, Contact Lens & Anterior Eye (27) 2004 149156 
dbracer, 
The above paper discusses fusarium solani, the problem is not the solutions any of which would be highly effective if given the proper rub time and soak, but with more wearers wanting to skip steps and time the increase in cases infections will continue to rise, unless the regimen is changed or the solutions are made stronger and if they are made stronger I would assume their would be concerns about the toxicity of the active ingredients. I could e-mail you the paper above if you PM me your address.

----------


## dbracer

> Contribution of regimen steps to disinfection of hydrophilic contact lenses, Contact Lens & Anterior Eye (27) 2004 149156 
> dbracer, 
> The above paper discusses fusarium solani, the problem is not the solutions any of which would be highly effective if given the proper rub time and soak, but with more wearers wanting to skip steps and time the increase in cases infections will continue to rise, unless the regimen is changed or the solutions are made stronger and if they are made stronger I would assume their would be concerns about the toxicity of the active ingredients. I could e-mail you the paper above if you PM me your address.


HarryC,

Yes, I agree that the solutions really aren't the problem. Compliance is. 

But I also get the distinct impression that an agency that was created post WWII for the control of malaria (the CDC) has very little to do, and CL companies are on their hit list.  

B&L was hung out to dry on flimsy evidence at best with no regard for the consequences except for a feather in some bureaucrats cap, especially considering that the same outbreak in Europe had no relationship to Moisterloc.   

Sorry I got off on that tangent, but the CDC needs to be cut from the federal budget. They probably read forums like this; and I'm probably the next SOB on their radar. 

I'll send you my email, PM. 

Respectfully,
dbracer

----------


## HarryChiling

> HarryC,
> 
> Yes, I agree that the solutions really aren't the problem. Compliance is. 
> 
> But I also get the distinct impression that an agency that was created post WWII for the control of malaria (the CDC) has very little to do, and CL companies are on their hit list. 
> 
> B&L was hung out to dry on flimsy evidence at best with no regard for the consequences except for a feather in some bureaucrats cap, especially considering that the same outbreak in Europe had no relationship to Moisterloc. 
> 
> Sorry I got off on that tangent, but the CDC needs to be cut from the federal budget. They probably read forums like this; and I'm probably the next SOB on their radar. 
> ...


I agree not much evidence, actually a case could be made that global warming has lead to the increase in temperature thus leading to a more optimal enviornment for these fungus to grow.  I kind of brought up the article and posted those graphs because it supports your point and mine.  If the case against moistureloc was weak at best and it performs the best out of the solutions, then we have a slight problem.

----------


## chip anderson

If the lens and the solutions contained therein can't stand 98.6 degrees they ain't woth nuthin.   Global warming hasn't effected this.
And yes it is the solutions not so much compliance as we have attempted to make "compliance" so simple thinking the patients were such dunderheads or "our precious time" was too valuable to give proper instructions that we dumbed down the system.  We made it as simple as possible and then the patients cut down on what was an already precariously minimal appliation.
The best system we ever had was when We had the Ciba (or was it allergan) peroxide system, the slightly gritty cleaner, and Unpreserved Aerosol saline, and an eyzyme cleaner that worked in peroxide.  The manufacturer didn't like putting other peoples products in the kit, so it got "simplified" for compliance.

Chip

----------


## dbracer

I think HarryC may be on to something here.

The problem in all CL solutions is GLOBAL WARMING! Not just any global warming, but GREENHOUSE GAS GLOBAL WARMING.

That's the worse kind. We've past bill after bill and reduced emissions logarithmically.  But it has done absolutely no good.  So now it's worked its way into our industry. Damnit!!

Actually the best solution system on the market was Quickcare, as long as they use the cleaner. Ain't much that can get around isopropyl alcohol. I see that they've put Miraflow (I believe sp??) back on the market. 

dbracer

----------


## eromitlab

I'm still trying to figure out the best cleaning system for my RGP patients. Most stick with Boston Original, because it's what they know. We get Simplus from our lab with every pair of lenses made, which I'm not too fond of (I only asked about it a few pages back to get a more 'educated' opinion of the solution). My doc thinks that the LoBob Optimum system is a good one, but I have has several patients complain about the re-wetting drops and that it's pretty much not available in the area. I would consider Clear Care, but after seeing some of the comments, I guess that's not a good idea either.

What are the favored systems for use with RGPs??

----------


## chip anderson

Don't use one-step stuff, makes lenses and case coat with deposits in a very short time.  Don't use any no-rub.  Boston Origional is better than other Boston's especially when combined with enzymatic clearer.  LoBob is good.

----------


## HarryChiling

> Don't use one-step stuff, makes lenses and case coat with deposits in a very short time. Don't use any no-rub. Boston Origional is better than other Boston's especially when combined with enzymatic clearer. LoBob is good.


I don't know, I would say use a one step, but instruct them to use them with enzyme cleaners.  I say use the no rub and tell them to rub.  I wish the manufacturers of these new solutions would just stop trying to eliminate the things that are needed to get th lenses clean.

No rub, thats like taking a shower with no soap.

----------


## chip anderson

Don't want to disagree with Harry here but:
Back in the day when we had only PMMA lenses the only patient (or in some cases fitter advise) caused problems I saw were due to:
Dry storage, combination solutions, and handling lenses over the sink.
I almost never saw deposits on lenses except when combination solutions or dry storage were used. I always saw scratches when the patient rinsed lenses over the sink.
Now bear in mind this takes in 49 years of all stages of CL, mfg and retail fitting. I always examine every lens on the patient with slit-lamp and remove the lens and examine it under 7x magnification under various forms of lighting. I polish off scratches and deposits _when indicated_. I see deposits on almost all HGP's and soft lenses over 6 months old, some times a lot less, sometimes a lot more. In some cases you will see almost none but once polishing has begun one will see "invisible" deposits being removed in layers like layers of cellophane being ground off as one polishes.
Now this isn't scientific and I have no electron microscope, but it's what experience has shown me. But patient's (with a few exceptions of non-rotating fits, and some with a lot of goo always in the eye) with good cleaning/storage habits, lenses stay cleaner.
I often feel that some of the deposits are storage solution components, I have seen many long stored "new" contacts with deposits. Most of the spair pairs in both PMMA and HGP will have deposits if stored wet. I try to always advise patients to keep lenses that are going to be stored and not worn for long periods of time to: "Clean lenses thoughly, blot off all moisture and store lenses in a dry flat pack." You will see practially no warpage or deposits even with decades of storage in this manner. However, I hope obviously, lenses that are going to be worn at least weekly should be stored wet.

This combined with the difficulty in pre-inspection makes me wonder why some mfg.'s ship lenses wet.

Chip

----------


## rdcoach5

Even the sales reps are advising us to ignore the instructions on their own No-Rub solutions. We hear that the product recalls for patients getting infections from their solutions is really the fault of the patients improper use of the product. Most of the patients with infection were not only not rubbing their contacts, which does 80% of the disinfecting, but were also re-using their solution.In other words, the patients were taking their lenses off dirty and soaking dirty in the same solution for days or weeks at a time. I tell my patients, if you didn't rub it you didn't clean it and you always clean your case between uses with very hot tap water and dry with a clean towel by rubbing.Frequent replacement of cases is also recommended or disinfecting with peroxide.
Bob Taylor

----------


## HarryChiling

> This combined with the difficulty in pre-inspection makes me wonder why some mfg.'s ship lenses wet.


Chip,

Your supposed too, but how many offices check RGP's for correct parameters?  I would be suprised if my doctor knew how to work a radiuscope.

----------


## chip anderson

Harry:  None of them do, this can also be done with a keratometer and a con-ta-check.  The fact that none of them do is one good reason why they should not be "fitting" contact lenses.  I find that rejects for base curve alone (and sadly I have learned to accept .25 dio tolerance instead of .12 dio.) run 20%.  I sometimes find base curves as much as two diopters off, appearently where someone pulled the wrong button off the shelf or miss-converted diopters to millimeters.  This could easlily result in a corneal ulcer in a short time, especially if no one bothered to view the lens on the eye and just handed or had direct mailed the lens to the patient.
I also see lenses where no peripherial curves or vastly insufficent curves were on the lens.  Edges that are squared instead of properly tapered and rolled.  Honestly I don't see how practioners and manufacturers stay out of lawsuits with the lenses sent out.
I can't tell you how high the percent of lenses with unpolished lathe marks, especially of lenticular or other semi special design.  The optics now that most manufacturers are willing to polish center out as opposed to edge to center are horrible on 90% of rigid lenses, stronger the power, the worse the optics.  There is a reason these aren't "good as glass" in the lensometer.
I origionally came to Mississippi from Texas knowing that the contact lenses available where horrible, too thick, distorted, poorly finished, etc. thinking I would make a fortune here.  I found that when I made calls he practioners where interested in price, who the stockholders of the compay where (O.D's wanted O.D. stockholders, M.D.' wanted MD's, etc.)  None of them had even such rudimentary instruments for checking lenses as a thickness gauge.  Even less knew how to use inspection equipment if they had any in the shop.

Chip;)

----------


## Berno

Hi Steph!
Just another way to answer your first question- I think B is the right answer and the reason is because 42.5D (7.9mm) is flatter by 0.4mm than the base curve [this corresponds with the cornea's shape which is steeper in the centre and getting flatter toward the periphery (assuming it's not a postK cornea and it's not RGL lens)
(a) and (c) are steeper which is not likely in normal geometry lenses and (d) 30 is way too flat.
Hope I helped.

----------


## HarryChiling

Here is some awesome research done into the biocompatibilty of solutions to materials. This was truly a find and shows that all solutions aren't built equal as well as some solutions will work well for some materials and some solutions fail for certain materials. If your office uses the hand them whatever's on the shelf system you may want to rethink it.

http://www.staininggrid.com/

Also check out a similar spin off:

http://www/staininggrid-japan.com

I would love to hear comments.

----------


## rdcoach5

We don't see the irritation from our patients that this study would predict. Anyone else?

----------


## rdcoach5

> Ah Chip!! I believe me book has some wrong answers. I have for the answers both as being B. Hmmmm... interesting. Well at least now I know when I question things it is usually with good reason. I don't have a chart as I have never had a reason to get the contact lens books. Thanks for all your help this has cleared some things up. At least til I get stuck again. Lord knows it is likely to happen any minute. 
> Thanks Again!
> Steph"I am gonna end up in a rubber room before I am finished with cls."D


As a general rule I use an intermediate curve 1.5 Diop flatter than Base curve =9.00 or 43.50 Diop and a Peripheral Curve 1.5 Diop flatter than the intermediate =10.50 or 42.00 Diop. It's easy to flatten from here if needed. 
                          Bob Taylor

----------


## eromitlab

> Chip,
> 
> Your supposed too, but how many offices check RGP's for correct parameters?  I would be suprised if my doctor knew how to work a radiuscope.


we have one... but doc never uses it... he couldn't even get it calibrated.:drop:

----------


## chip anderson

If they don't impress the importance of and teach them how to check lenses what the hell do they teach them in optometric school or the "exensive 18 hours of contact lens training" in residency?
These people are those with power over us in contact lens fitting?

Chip

----------


## dbracer

> If they don't impress the importance of and teach them how to check lenses what the hell do they teach them in optometric school or the "exensive 18 hours of contact lens training" in residency?
> These people are those with power over us in contact lens fitting?
> 
> Chip


Chip,
Just because we have "power over you" has nothing with whether, in a given area, we are smarter or better. To the contrary. The Opticians that I know do great work. Some better than mine. 

I'll be the first to admit that I don't check my RGP's as well as I should. 

It's all a matter of priorities. With the advent of HIPPA and baffling change in optometric practice, those things that are of lesser liability and cash flow importance take the back burner. 

Of the two liability takes priority. The south end of litigation ain't funny,  I've been there. 

Don't get me wrong. I love my profession even more, but 20 years ago I could prescribe ophthalmics.  That's about it. 

Now it's ophthalmics, intra-clinic diagnostic meds, topical lub therapeutics to oral narcotics, limited injections, superficial surgeries, CL's by topography, pre & post-op work,meds & directions, GP's asking me for advice, consults with neurologists, pediatrics, internists, and endocrinologist. 

Not to mention, as ya'all know the rise in ophthalmic technology is boundless. Individualized laser wavefront guide glasses are being done but currently it's impractical.  Corneal topographies for the average optometric office was also a decade ago. 

I'm sure their are some tasks even in your businesses that have been pushed to lower priority.  

*In short:  keeping up with the evolution is no small task!*

I know. I know. It's no excuse, but it's the answer. It's exciting, but it's also exhausting. 

Respectfully,
dbracer

----------


## dbracer

> Here is some awesome research done into the biocompatibilty of solutions to materials. This was truly a find and shows that all solutions aren't built equal as well as some solutions will work well for some materials and some solutions fail for certain materials. If your office uses the hand them whatever's on the shelf system you may want to rethink it.
> 
> http://www.staininggrid.com/
> 
> Also check out a similar spin off:
> 
> http://www/staininggrid-japan.com
> 
> I would love to hear comments.


I don't know Harry. I used to fall for the staingrid thing a lot.
Alcon is the shrouded sponsor, and I find it interesting that their products come out looking better. 

Of course they're no fools this is an "on the average" thing. Looking too good would be overly suspicious.

Why not just state in big letters: "*Brought to you by Alcon*."

Respectfully,
dbracer

----------


## HarryChiling

> I don't know Harry. I used to fall for the staingrid thing a lot.
> Alcon is the shrouded sponsor, and I find it interesting that their products come out looking better. 
> 
> Of course they're no fools this is an "on the average" thing. Looking too good would be overly suspicious.
> 
> Why not just state in big letters: "*Brought to you by Alcon*."
> 
> Respectfully,
> dbracer


Yes, Alcon is funding the doc who did this study, but none the less it is interesting to see.  Has anyone applied his methodolgy in office and found the results differ?

----------


## dbracer

> Yes, Alcon is funding the doc who did this study, but none the less it is interesting to see.  Has anyone applied his methodolgy in office and found the results differ?



Good point, Harry. 

I sure haven't. I'd rather be on the archery range when I've got a spare moment. 

dbracer

----------


## eromitlab

> If they don't impress the importance of and teach them how to check lenses what the hell do they teach them in optometric school or the "exensive 18 hours of contact lens training" in residency?
> These people are those with power over us in contact lens fitting?
> 
> Chip


this is why I'm trying to educate myself further... I know he's too busy to probably do everything by the book or absolutely correct, but, he pays me to be his assistant... so, why can't I take over the load? It's not like we have a huge contact lens fitting business going on here anyhow (we're mostly medically focused), but with my help doing it right and in fewer redos would certainly be a shot in the arm for the practice.

excuse me for asking, though... what would your folks recommend as far as textbooks and educational materials for the emerging contact lens technician? I have already purchased two, _Current Contact Lens Practice_ by Efron and _Manual of Contact Lens Fitting and Prescribing_ by Hom and Bruce.

Any other resources would you suggest??

Thanks Loads!!

~eromitlab

----------


## HarryChiling

> this is why I'm trying to educate myself further... I know he's too busy to probably do everything by the book or absolutely correct, but, he pays me to be his assistant... so, why can't I take over the load? It's not like we have a huge contact lens fitting business going on here anyhow (we're mostly medically focused), but with my help doing it right and in fewer redos would certainly be a shot in the arm for the practice.
> 
> excuse me for asking, though... what would your folks recommend as far as textbooks and educational materials for the emerging contact lens technician? I have already purchased two, _Current Contact Lens Practice_ by Efron and _Manual of Contact Lens Fitting and Prescribing_ by Hom and Bruce.
> 
> Any other resources would you suggest??
> 
> Thanks Loads!!
> 
> ~eromitlab


Contact Lens Manual from CLSA both volume I and II are great office resources.  Also if you join the CLSA they provide you with a publication called the Eyewitness, great articles and very little fluff so it acts as a great resource.  I would also suggest:

Contact Lenses (5th) - author Phillips/ Speedwell
Contact Lens Manual - author Gasson/ Morris
Contact Lenses A-Z - Efron 
Essential Contact Lens Practice - Veys, Meyler and Davies 
Eye Essentials - Rigid Gas-Permeable Lens Fitting - Andrew Franklin & Ngaire Franklin 
Eye Essentials - Soft Lens Fitting'_ - Andrew Franklin & Ngaire Franklin_
Manual of Gas Permeable Contact Lenses'_ - E. Bennett & M. Hom_

JCAHPO and CLOA have a Contact Lens Learnign Systems CD-Rom also I've heard the learnign systems CD-Roms are pretty good, but expensive.

JCAHPO also offers a Contact Lens Course - it's basic to intermediate.

----------


## eromitlab

awesome! thanks for the info, Harry!! 

n.b: I just realised that I mis quoted the title of the Efron's book, it's _Contact Lens Practice_, I just got my copy in the mail and noticed the mistake. I bought it on the glowing reviews it got on the book review forum. Just quickly flipped though it, and I can already tell it's a great text to have.

----------


## tmorse

> Any other resources would you suggest??
> ~eromitlab


*Fitting Guide for Rigid and Soft Contact Lenses* by Stein and Slatt
This book is considered the 'bible' for contact lenses here in Canada:cheers:

----------


## HarryChiling

> *Fitting Guide for Rigid and Soft Contact Lenses* by Stein and Slatt
> This book is considered the 'bible' for contact lenses here in Canada:cheers:


I just bought a copy of the second edition for $0.40, I figure if Ted's cocky self likes the book it's got to be good :D try this link:

http://books.onlineopticianry.com

----------


## tmorse

> I figure if Ted's cocky self likes the book it's got to be good :D try this link:
> 
> http://books.onlineopticianry.com


Hey Harry, up here in Canada we keep information on our personal endowments private.:p

----------


## HarryChiling

> Hey Harry, up here in Canada we keep information on our personal endowments private.:p


Maybe arrogant would have been a better description :D, but none the less thanks for the tip on the book.

----------


## loratz

SOMETIMES SPIT WORKS PRETTY WELL :Rolleyes:

----------


## chip anderson

Loratz:


No spit on Contact Lenses.  I have made enough artificial eyes for one lifetime.  No need to increase my market.

Chip

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## Fezz

> Loratz:
> 
> 
> No spit on Contact Lenses. I have made enough artificial eyes for one lifetime. No need to increase my market.
> 
> Chip


Chip-

Your missing the boat here. If you would teach Harry Chiling and myself your art, we could carry on your legacy up North. 

Infections for all!!!

:D

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## tmorse

> Maybe arrogant would have been a better description :D, but none the less thanks for the tip on the book.


:cheers:

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## HarryChiling

I know chip likes to fit using nomograms and intuition but for us novices I have put online a favorite nomogram for GP lens fitting, enjoy. The soft lens version will be posted up there soon.

http://www.technicalopticians.org

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## HarryChiling

Soft lens nomogram is posted at:

http://www.technicalopticians.org

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## HarryChiling

> Cell Mitosis - Is the process of a cell splitting apart, replicating itself, cloning (probably shouldn't use this term in a biological process involving DNA, but you know what I mean). The cell goes through many phase in the process which is often the confusing part.
> InterphaseProphasePrometaphaseMetaphaseAnaphaseTelophaseCytokenisisSometimes you will also include interphase although technically it is not part of the cell division process. The different phases are marked by characteristic changes in the cell. Basically the cell starts by condensing the necleus, the poles move to the opposite ends, the necleus membrane dissolves, the chromosomes line up, they split, they travel towards the poles, the new membranes form around each cell necleus, the cells break apart.
> 
> That last explanation is the nitty gritty in english version you asked for, my wife is a biology teacher and can probabl explain it in so much detail your brain would hurt, but when teaching her students she does sometimes start with a break down like the one I have layed out, but a bit more accurate. Anyway you should get the drift, if not PM me and I will pass on any questions you might have.
> 
> dbracer - great explanation of Dk/t. I liked the quick small letter explanation as well when defining the constant.


A few pages back some one asked a question about cell mitosis and the explanation was posted, but my wife is in that part of her lesson and was taking pictures through a microscope of cells. So I thought wouldn't it be fun to put them up for people to guess what's happening.

From the images below match the phase of mitosis with the image

No 1 - ?
No 2 - ?
No 3 - ?
No 4 - ?
No 5 - ?
No 6 - ?

No 7 - Can you tell if this is an animal cell or a plant cell?

No 8 - What characteristic lead you to believe your conclusion to answer No 7?

[spoiler=For Answers Click Here]No 1 - Anaphase \nNo 2 - Telophase\nNo 3 - Prophase\nNo 4 - Between Prometaphase and Metaphase\nNo 5 - Metaphase\nNo 6 - Between Telophase and Cytokenisis\nNo 7 - Plant Cell\nNo 8 - Only plant cells have cell walls, animal cells have cell membranes. This would account for a square shape rather than an oval or round shape.\n\nThanks for Playing[/spoiler]

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## HarryChiling

*Here are some more contact related questions. Try them out before you check your answers.*

1. The most refractive power comes from which component of the eye?
Crystalline LensPosterior Corneal SurfaceAnterior Corneal SurfaceAqueous and Vitreous2. In the reduced Gullstrand Schematic Eye the index for the eye is?
1.331.3371.3361.373. A patient presents with K's of 40.00@180 / 40.50@090 the patient wants soft lenses. What base curve would you fit the patient in?
SteepMedianFlat4. A patient with HVID of 11mm wants soft lenses what would be the intitial choice for diameter?
12mm1.4cm12cm11mm15mm5. If the radius of a lens is made larger, would the lens get?
SteeperFlatterDepends on diameterB and CA and C[spoiler=Answers]1 - C\n2 - A\n3 - C\n4 - B\n5 - D (although B itself is acceptable)\n\nThanks for trying[/spoiler]

----------


## chip anderson

Harry:  What is HVID?   What is alger?

I thought I knowed this stuff pretty well but I don't know what either is.


Chip

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## HarryChiling

> Harry: What is HVID? What is alger?
> 
> I thought I knowed this stuff pretty well but I don't know what either is.
> 
> 
> Chip


Horizontal Visible Iris Diameter (fancy term for the size of the iris), alger was a mispelling it's larger, sorry.

----------


## chip anderson

Just a little known fact to add to mixture.  The actual corneal diameter (verified by a lot of moulds taken many years ago) is usuall abot 1.4 mm larger than the visible iris diamter.  With 13.7 being average.

Chip

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## HarryChiling

> Just a little known fact to add to mixture. The actual corneal diameter (verified by a lot of moulds taken many years ago) is usuall abot 1.4 mm larger than the visible iris diamter. With 13.7 being average.
> 
> Chip


That could have made for a great question.  I believe the average HVID today is considered 11.6mm - 12.0mm.

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## jrumbaug

Harry, I think I'll fuss over the suggested answers to #5 being (d. or b.) 

5. If the radius of a lens is made larger, would the lens get? 
SteeperFlatterDepends on diameterB and CA and CYou did say (b) alone is OK, which I think is th only answer. I say regardless of the diameter, as the radius increases, the lens is flatter. The question does not say anything about changing the diameter when the the radius changes. The answer C hints at the fact that the fit is a function of diameter and curvature, which is true. But the answer C, realy does not aply to the question.

Now to put out another idea, had the question read, "What happens when the radius is made smaller?". It is possible to order a base curve that is so tight that it can not be made in the requested diameter because the radius would describe a sphere smaller that the requested diameter, but this is getting pretty far out there. ( dia= 9.4, bc = 4.85 , would have to be a REAL THICK lens to reach 9.4 )

That's my 2 cents for the day 

Jim Rumbaugh

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## HarryChiling

> Harry, I think I'll fuss over the suggested answers to #5 being (d. or b.) 
> 
> 5. If the radius of a lens is made larger, would the lens get? 
> SteeperFlatterDepends on diameterB and CA and CYou did say (b) alone is OK, which I think is th only answer. I say regardless of the diameter, as the radius increases, the lens is flatter. The question does not say anything about changing the diameter when the the radius changes. The answer C hints at the fact that the fit is a function of diameter and curvature, which is true. But the answer C, realy does not aply to the question.
> 
> Now to put out another idea, had the question read, "What happens when the radius is made smaller?". It is possible to order a base curve that is so tight that it can not be made in the requested diameter because the radius would describe a sphere smaller that the requested diameter, but this is getting pretty far out there. ( dia= 9.4, bc = 4.85 , would have to be a REAL THICK lens to reach 9.4 )
> 
> That's my 2 cents for the day 
> 
> Jim Rumbaugh


Thanks Jim,

Originally I though the same as you did but was anticipating someone argueing that it would depend on if the diameter stayed the same or not, so I thought I would put it both ways to try and cover my bases.

Good to see that you took it.  I will put more up.

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## chip anderson

Rigid lenses rule:
1: Either the lens is too damn flat or it's too damn big.

Softlens rules:
1: If the lens hurts it's too flat, has trash under it, is wrong side out or is damaged.
2: If the lens doesn't center or moves excessively it's too flat or too small.
3: If vision fluctuates, particularly improving after squeezing lids tight or rubbing and deteriorated before blink, lens is too steep.

Are there other factors, like edge design, modum (hoop strength) allergy, etc. Sure but if you just get and keep the above straight in your mind you will be way ahead of most in this business.

Chip

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## dbracer

> Horizontal Visible Iris Diameter (fancy term for the size of the iris), alger was a mispelling it's larger, sorry.


Harry,

Actually Alger is the name of a guy who devised a motor operated bur to remove corneal rust-rings.

It's called an Alger Brush.;)

Okay, Okay. So much for schmartypantz answers. 

Respectfully,
dbracer

----------


## HarryChiling

> Harry,
> 
> Actually Alger is the name of a guy who devised a motor operated bur to remove corneal rust-rings.
> 
> It's called an Alger Brush.;)
> 
> Okay, Okay. So much for schmartypantz answers. 
> 
> Respectfully,
> dbracer


Thanks, I that's funny, but it was a misspelling.

----------


## dbracer

I was trying to pull you out of the fire there.

But, Oh well. :cry:  Have it your way.

Respectfully,
dbracer

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## HarryChiling

> I was trying to pull you out of the fire there.
> 
> But, Oh well. Have it your way.
> 
> Respectfully,
> dbracer


Thanks again.  I did burn myself with that one.  I did know about an alger brush though, and come to think of it it would make for a great trivia question.  It would be nice if there was a way to create question and answer tags for the forums [?]

----------


## rdcoach5

> I'm not sure peroxide cleans anything. It bleaches things and kills germs. But I don't know that it removes dirt. Or mixes oil with water.
> 
> Chip


Someone came in today to get her contacts polished. Somebody did the polishing but did not finish with a peroxide cleaning -nor a boston conditioner rubbing/cleaning to remove the polish.She used the rinse with water which does not work. Result ? Superficial abrasions on both eyes.I can't believe that the opticians who still actually polish contacts do not use peroxide to remove polish and to immediately disinfect their contacts. Again,you rub the peroxide into the len as you are rinsing it with tap water. It will feel squeeky clean. It will be clean. When doing an enzyme cleaning on a gas perm, use peroxide instead of saline and the enzyme softened protein comes right off. To those of you who scoff about this -I've used this successfully 28 years with never a reaction. And my pts  do not get reactions after I  polish their contacts.

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## eromitlab

I feel bad that I haven't been posting any questions... instead I'm runnin' my mouth off in other threads like a yahoo instead of learning something, which is why I come here... so... I have a question for those that are far more learned than I.

with respect to RGP materials: I have been researching RGP materials a little bit, just to see what's available to me and so I can be more familiar with them... it got me thinking about the hyper-Dk materials on the market and I came down to Menicon's Z material, which surprisingly to me, is approved for up to 30 nights of continuous wear (I didn't realize that wearing RGPs continuously for days was safe). 

My question: What are your feelings on continuous wear modality for rigid contacts? Is it something you would say should be avoided entirely, or under a very strict set of circumstances would it be acceptable to you? 

as a side note: I can see where the benefit could instantly be appreciated in an orthokeratology application, but that's usually where patients are sleeping in their lenses anyhow and leaving them out during waking hours, and possibly the increased lens flexure may not be acceptable for maximum effectivity, however, I digress... I'll ask about orthokeratology stuff at a later time.

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## chip anderson

My feelings on exteended wear.  Except in those situations where there might be a compelling indication (i.e. combat, a romatic weekend where you want to see what your are enjoying), extended wear is foolish.  My attitude might be different if I were so impared that I couldn't see who was on the other side of the bed.  But as a rule I tell my patients: "Like your mother said: Any thing you sleep with is more likely to give you problems."
Now as to the little known and oft forgotten facts.
I once saw Fred Danker remove a PMMA lens that he had worn continuously for 27 years without damage.  He had forgotten how to remove it and he didn't belive the posterior surface needed to be polished.
I once read a report from a group of ophthalmolgist in Boston who as a an experiment built up to 24 hr a day wear in PMMA lenses, wore them for 90 days (without damage) and reported that that had discomfort after removal.  Eventually had to use a removal (reverse wearing) schedule to wean themselves away from the lenses.
Of course this is back when we felt the mechanics and skill of the fitter was more important than the material.

Chip

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## xiaowei

> My attitude might be different if I were so impared that I couldn't see who was on the other side of the bed. But as a rule I tell my patients: "Like your mother said: *Any thing you sleep with is more likely to give you problems*."
> 
> Chip


I really like this one!:bbg: 
But at least, you should be able to recognize what caused the problems......:D:D

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## eromitlab

Hey folks, I have another question:

Does anyone know of a resource that has a listing of specific soft lens specs, like OZD, lens edge thicknesses and other technical data? I know that the TQ is probably the most complete general lens reference, but... I am wondering if there is a more detailed accounting of lens data out there.

As always, thanks for any input!!

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## chip anderson

Pretty sure TQ gives Oz. as to rest of data, at least what is available (not not concidered *propriatory*) should either be in CLQ, or available from manufactures in thier data sheets (from either the mfg. or rep.)
Jobson Review of Cornea and Contact Lenses (frames data) Annual Contact Lenses and Lens Care Guide gives most of the information you desire.

Chip

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## rdcoach5

Contact Lens Forum used to post an online listing of Solutions and Contact Lenses online but have dropped it. Does anyone else do it now?

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## HarryChiling

> Contact Lens Forum used to post an online listing of Solutions and Contact Lenses online but have dropped it. Does anyone else do it now?


http://contacts.onlineopticianry.com or through the http://optics.onlineopticianry.com search engine you can do a search haven't had the time to update it in a little while but a lot of info in there either way.

Also the reference you talked about Dick is CLASS Contact Lenses and Solutions Summary which is a suplement provided by Vistakon found in CL Spectrum magazine once a year, you can print off the pages here, suprisingly a good resource even though it is put out by Vistakon it includes accurate and complete data from various CL manufacturers:

http://www.clspectrum.com/supplement...8&tm=6/30/2008

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## eromitlab

I can't seem to find a cheat sheet for RGP manufacturing tolerances anywhere. I know that the Efron text mentioned earlier in the thread has such a thing in the appendix, but that's at home and I'm here at work. Does anyone know where I might find one? Google turns a lot of hits, but I don't have the time to check through all of them.

T I A!!

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## optiman37

One general rule I have learned when you are cleanning contact lenses is not to use water even to soak the lenses because water contains amobes

jeff

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## HarryChiling

Z80.2 - 1989, is the RGP ANSI standard

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## fukajia

why not? 
When we have the forum? 
:cheers:

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## chip anderson

Just the other day I had a patient in with RGP's so coated you couldn't even tell the color of the plastic.  I sprayed one lens in flat pack with Perma-Brite (a cleaner mostly EDTA, formerly known as Obrite) sold by Danker/Utica labs.   I was interupted for a few minites and returned, the sprayed lens had returned to it's origional color and shined like brand new.
I took it back to the patient and showed him the cleaned and uncleaned lens in a white flat pack.  He immeadiately became a believer in cleaning his lenses and coming in for his bi-annual check-ups.
I have known since the '60's that PermaBrite was an excellent cleaner and often found that "new" lenses when they came from the lab would not "wet" properly.    If I sprayed and rubbed, and rinsed these new lenses and then rubbed them as I should with proper "wetting" or "conditioning" solution the lens would wet excellently.
I have for decades advised my rigid bifocal contact lens patients to clean with Perma-Brite prior to overnight storage.
And no I don't have any financial (other than I owe them money at the end of each month) interest in Danker/Utica labs.

Chip

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## rdcoach5

I thought Chip and some others would appreciate this over-wearing story. I had a pt , one of the few, who was a really successful extended wear  person. Back in the 70's, we would insist all extended wear patients return after 1st day of sleeping in lenses and if all looked good, return for periodic checks.Only those who did not show deposits were allowed to go a full 2 weeks. Now, this one patient , after 30 days of wear, looked like she had just inserted them. She was instructed to continue monthly wear if everything remained the same. Two and 1/2 years leater she was in for an exam and admitted she had not removed the contacts at all because it took them a day to feel real comfortable again. Amazingly, the contacts were removed and examined for deposits to find that they were still free of deposits but had yellowed slighty. I explained to my patient the dangers of over-wear, she was an RN, after-all, and she agreed not to repeat the over-wear. Next time I saw this patient, she again admitted to wearing these conact lenses for a year and a half. She had corneas that looked like a non-contact lens wearer-no neovasc at all and the contact were free of deposits or protein. I believe the contacts were Hydrocurve torics.

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## eromitlab

WOW! That is unbelieveable. Even with non-compliancy, the lenses still looked ok?? No neo but how did her endothelial cells look?? how about K's or topo? any distortion? I find it hard to believe that someone wearing a lens continuously like that would not have some morphological changes or irregular topo/K readings.

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## chip anderson

For what it's worth I was in Las Vegas (Back when there was still money in contacts) for a CLSA Meeting.  In fact It was when I took my FCLSA exam many, many decades ago.  
Fred Danker was there with a PMMA lens on that he had not removed for 27 years.  He had even forgotten how to remove it.   He did remove it as was examined by many experience fitters and OMD's and no one could find anything wrong with Mr. Fred's eye.


Chip

And no, I am not advocating exteended wear of PMMA or any other type of contact.   Just relating what I was told, I was there but I did not examine Mr. Danker.

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## rdcoach5

> WOW! That is unbelieveable. Even with non-compliancy, the lenses still looked ok?? No neo but how did her endothelial cells look?? how about K's or topo? any distortion? I find it hard to believe that someone wearing a lens continuously like that would not have some morphological changes or irregular topo/K readings.


The only thing abnormal was the yellowing of the contact lenses. I'm not sure if this was from natural epinephrine in her tears or exposure to cigarette smoke. Visual acuity was 20/20 still and corneas crystal clear.

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## rdcoach5

It's been almost 2 years since anyone has added to this long-running post started by Chip. Let's start a new one by asking what everyone thinks are the pros/cons of the silicone hydrogels that have taken over. Favorite brands?

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## eromitlab

Wow. It has been a long time. I've been busy with grad school and just working a busy practice so getting on OB hasn't really crossed my mind. I just got a notification on my phone this morning (hooray for smartphones) that someone had posted to this thread. Anyhow... 

I am a big fan of SiHy lenses... the off-the-shelf products that are available work incredibly well for my soft lens patients 95% of the time. I absolutely am in love with Biofinity lenses right now and enjoy (knock on wood) almost 100% first fit success with them. I haven't really been an ardent Cooper fan in the past but the Biofinity products have really given me cause to look at their product portfolio more and more as of late. I usually dispense with Bio True and Blink Contacts for solutions and have had incredibly positive feedback. This is coming from established patients of my practice as well as newer patients that come to us with complaints regarding their lenses or the ECP that was fitting them... I see a lot of what other guys would call 'problem patients' where I work and many times all it takes is switching to SiHy. While SiHy isn't a magic bullet lens that solves all the world's contact lens problems... it has certainly helped a lot of patients that I see.

To open a can of worms, so to speak... I think that some of the issues I see patients coming in with are due to a lack of initiative to learn about new products on the part of the ECPs. A good number of patients that are coming new to the practice I work for are still being fit with older hydrogels and not even being educated about the newer technologies that are available or about proper care and replacement. I can think of one patient this week who was fit with SofLens MF last year and has been unable to wear them comfortably since being fit. When she went to the OD that fit her, he told her that there was nothing better available and that this was it for her in terms of soft lenses. What are some impressions about the ECP community maybe not taking a stake in raising the standard by engaging actively in learning about new products and technologies and just sticking with what has worked for years past? Does anyone think it's okay to just stay 'in their box'?

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## rdcoach5

I agree with the positive feedback on Biofinity but we have had success also with Acuvue Oasys including both of their new Multifocals. We have also switched to Bio True  with positive results

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## uncut

Fantastic thread...I would agree that a separate CL section on the forum would be nice!  I love some of the new lens materials that are out, but improvements need to be made in edge design with some.  They are like rocks for some people who are used to more invisible/thinner lens.  I wish there were more base curves, too.

Eromitlab, you mentioned initiative to learn about new products on the part of the ECPs.  I find it difficult to find enough readily available information about lenses beyond the simplistic glossy brochures and postcards the manufacturers send out.  The reps tend to not know much beyond the glossy brochure.  If you have a chance to shadowgraph some of the lenses, you will find the base curves stated are not the true curvature, in some brands.  I think that a veteran contact lens fitter becomes skeptical and chair time defensive because of all the epic fails the industry has heaped upon them.  A successful contact lens fitting does not exist until several years has transpired.

----------


## rdcoach5

We have switched our soft lens starter kit to Bio-True . So far, so good. Anyone else have any results on this solution?

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## jrumbaug

not scientific but....
my wife likes Bio-True  (better than Renu )

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## uncut

> We have switched our soft lens starter kit to Bio-True . So far, so good. Anyone else have any results on this solution?


For educational purposes.....Post with more info re:Bio-True, chemistry, technique for use, maker, drawbacks..... for example.

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## Wes

I fitted my ex-gf, who was a CPOT, with Air Optix N&D 8.6, purevision 8.6 and Oasys 8.8, and she raved about the oasys.  Didnt care for the others.  She did have big dry eyes...

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## uncut

> I fitted my ex-gf, who was a CPOT, with Air Optix N&D 8.6, purevision 8.6 and Oasys 8.8, and she raved about the oasys. Didnt care for the others. She did have big dry eyes...


Could it have been that 8.80 base curve that gave her the rave-ability?

----------


## rdcoach5

> For educational purposes.....Post with more info re:Bio-True, chemistry, technique for use, maker, drawbacks..... for example.


Bausch & Lomb makes Bio True. It's their new all in one solution for soft lenses. I have not seen any negative reactions, yet. It's supposed to mimic the natural tear chemistry using hyaluranon to keep contacts lubricated and helps remove denatured protein. The wettable coatings on the new contacts like Oasys and Biofinity also help keep denatured proteins from binding to lenses.

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## Wes

> Could it have been that 8.80 base curve that gave her the rave-ability?


That's what we thought, and it certainly covered the "big" part. She also liked them for the moisture. Dry eyes and all...  Like I said, she was a CPOT. If she could've sat on the opposite side of the slit lamp from herself, she could've fit them as well.

----------


## rdcoach5

We've also had good results from the Oasys and Air Optix bifocals. They each have 3 bifocal strengths. Now, if only Biofinity had as good a bifocal in 2 base curves. I know that won't happen but it would be good for those big dry eyes.

----------


## Geirskogul

We've been attempting to fit quite a few sets of the Air Optix MF lenses, and they seem to be working better than the old SofLens MFs, but still not great.  I would say over half of our successful MF CL fits have been on the second try or after, with both of our optometrists, which is strange because I couldn't think of two exam and fit techniques that are more different.

I've just been trying the new PureVision 2 HD lenses (-4.75 OU) for a few days, and I'm on the fence.  On one hand, the fit, vision, and overnight-wear feeling after four days isn't any different than my all-time favorite lens, the Focus (Air Optix) N&D, but on the other hand, the fit, vision, and overnight-wear feeling is the same as the N&Ds.  I don't feel anything different in a negative respect, but there's no "WOW" factor like the B&L rep assured me everyone else has had.  Now, if they were less per box than the N&Ds, I'd be all over them; they're PureVision lenses, though, so they don't cost less than just about anything else we have.

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## Contacts2020

I can tell you that we sell more of the Air Optix Mulfocal and than any other multifocal lens. The 2nd runner up is the Biofinity Multifocal. Both are great lenses and have definitely pulled away from the pack. Hope this helps

----------


## uncut

> I can tell you that we sell more of the Air Optix Mulfocal and than any other multifocal lens. The 2nd runner up is the Biofinity Multifocal. Both are great lenses and have definitely pulled away from the pack. Hope this helps



You claim to be a lens manufacturer?    R e a l l l l l y?   Hmmmmmmmmmmmm....your buried links say otherwise!   I call spammer!

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## mervinek

Question for all who fit contacts.... I have 2 ODs that tell patients it's ok to wear their contacts longer... for example, wear a 2 week (acuvue 2) lens for one month.  Wear a daily lens for 3 days.  They are writing the Rx that way.  I believe they are doing it to save the patients money.  I'm curious what your thoughts are on this.  I have always believed that this is BAD!  Corneal problems bad.  Thoughts?

----------


## Robert Martellaro

> Question for all who fit contacts.... I have 2 ODs that tell patients it's ok to wear their contacts longer... for example, wear a 2 week (acuvue 2) lens for one month.  Wear a daily lens for 3 days.  They are writing the Rx that way.  I believe they are doing it to save the patients money.  I'm curious what your thoughts are on this.  I have always believed that this is BAD!  Corneal problems bad.  Thoughts?


 It's the prescribers neck- they can expose as much of it as they want. That said, some might be able to go longer, heavy depositors might have to change sooner. One could time a follow-up at 3 weeks to determine the best schedule for each individual.

From a retired CL fitter...

Hope this helps,

Robert Martellaro

----------


## mervinek

> It's the prescribers neck- they can expose as much of it as they want. That said, some might be able to go longer, heavy depositors might have to change sooner. One could time a follow-up at 3 weeks to determine the best schedule for each individual.
> 
> From a retired CL fitter...
> 
> Hope this helps,
> 
> Robert Martellaro


Yes.  That does help.  Thank you!

----------


## Sveti15

I had a question about the best way to determine if a contact lens is warped. Do the lines in the radioscope just have to look blurry which means they are warped? Or what do I need to look for to determine warpage??

----------


## Robert Martellaro

> I had a question about the best way to determine if a contact lens is warped. Do the lines in the radioscope just have to look blurry which means they are warped? Or what do I need to look for to determine warpage??


The mires should be clear and sharp, making sure that the lens is clean and that the instrument is calibrated and focused (I usually didn't have access to a radiuscope, instead using a keratometer).

The base curve on a new non-toric/bitoric lens should measure the same in all meridians. Most fitters will accept 0.10mm (0.50 D) warpage before recommending replacement. For example, if the BC should be 8.00mm, a half diopter warp would measure 7.95mm/8.05mm.

Proper handling and storage will minimize warpage and extend lens life (provide that information during I&R training).

Best regards,

Robert Martellaro

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## ranahospital

It seems really a nice thought.

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## tmorse

> I had a question about the best way to determine if a contact lens is warped. Do the lines in the radioscope just have to look blurry which means they are warped? Or what do I need to look for to determine warpage??


On a spherical RGP lens, if your have only a few radiuscope mires on the spherical base curve clear at the same time, the surface is warped.

----------


## davidefolder

Hi Chip,  I would love to learn about your program.  Im definitely interested in learning more to pass the NCLE

----------

