Hi

Further to my posting in June regarding contact lenses to help with complications. (Thanks to Dr Grant Mason for advice) Briefly I suffer from facial pain in low lighting particularly when trying to read (PRK both eyes in 1995) I have been an outpatient at a local hospital (Opthamology, Optometry and Neurology) trying to remedy this for a year. Latest treatments have been wearing of glasses to correct discrepancy in eyes -aminostropia? This improved vision sharpness but has not resolved facial pain which seems to be triggered without constant 100w artifical lighting, particularly when reading. Nor-triptyline 50mg daily to prevent nerve pain.
Wearing of pih-hole glasses to help with glare.

On my most recent visit they noted another change in my refraction (3 in a year!) This has meant they are now going to give contact lenses a go. As appointments are usually rushed with clinics being choc-a-block and infrequent. Combined with a high impression that I am the only person 'on the books' with post prk problems. Please can you give me your opinions/help on the following.

1/ I have read the numerous post-op problems from glare,halos, HAO's etc. I still am mystified as to what my problem is - all I know is I struggle to focus indoors in natural daylight and specifically I am aware of letters ghosting & light shafts if I just look through my left eye. The struggle seems to bring on the pain. I think I can identify with the peripheral vision issues would these be more pronounced in lower lighting - any ideas if I fit ' a box'.
2/ When I wore contact lenses pre surgery my eyes where dry and I struggled. What kind of lenses would you recommend in view of this -also should I insist that a topographer is used to get an effective fit (again I dont know if they will be considering this).
3/ Although glasses helped me see a sharper image they seemed to reduce the light entering my eyes further - would there be a benefit to purchasing glasses without an anti reflective coating. As Im sure this marginal tinting had some impact.
4/ They have suggested using pilocarpine (pupil dilation drops) have you any knowledge of this helping by avoiding visual treatment zone.
5/ Are these ever changing refraction readings a result of PRK?

Finally ..
An optician recently told me that PRK was by far the worse surgery to have as the removal of the epithilum caused more glare and halo effect is this true?
Sorry it quite long - I tried to be as brief as I could - and sorry about the appalling medical spelling!

Extremelly appreciative of any advise you can give.

Your symptoms, being "triggered without constant 100w artificial lighting, particularly when reading." suggests a visual element to the problem. Anisometropia could be a factor, the glare from the scarring in your left eye, of course, not to forget corneal surface irregularity, pupil size issues and pupil fluctuation in response to all these factors. Bright lighting may simply be constricting your pupils to a point that would minimize some of these factors, relieving your symptoms. As your doctors have suggested, a trial of pilocarpine would be helpful and, if not helpful, then potentially diagnostic. Consider no more than a diluted solution (1/8%). (What are they waiting on?)

Diluted pilocarpine could effectively reduce some of the symptoms associated with anisometropia as well as symptoms associated with light falling outside of the ablation zone. On the other hand, pilocarpine (miosis) could, by concentrating light through the center of your pupil, reduce vision if the scarring in the left eye is more intense centrally. These factors have to be considered and an attempt made to break down the various factors so that each can be addressed as adequately as possible.

Your refraction has changed three times in the last year? You had PRK ten years ago so things should be fairly stable relative to your corneal surface, so this finding suggests instability in the accommodative elements (focus). Considering your history and symptoms, and your age, it is possible for the refraction to fluctuate but it is critical NOT to think of these fluctuations as arising from the corneal surface. Similarly, I can think of various reasons to use RGP lenses in your case but NOT on the presumption that your refraction is changing due to corneal surface changes. Your doctors need to recognize the complexity of the condition.

Regarding your previous contact lens experience, most CL problems are related to the fit. Fitting you now, post-PRK, is like comparing checkers to chess, which means that potential fitting errors have a much greater chance of being compounded. Topography is not a panacea for the typical lack of insight into designing RGPs. Getting the central lens curvatures correct is simple. IME, the peripheral and transitional curvatures are every bit as critical and something not well addressed by topography-based, software driven RGP design systems unless the user knows the system's limitations. While a topographer may be used as a tool, it does not equate specifically to a better lens. Over-reliance on technology with a lack of insight is, after all, what brings most patients to the VSRN bulletin board.

An anti-reflection coating puts MORE light into your eyes. Normal, uncoated, spectacle lenses reduce light entering the eye (by reflection) about 8%. A good AR coating allows 98+% of the light to reach the eye. With the description you have provided about your case, the benefits of an AR coating are questionable. What happens to the light as it passes through your corneas is many times more significant than what happens to it as it passes through your glasses. However, if you stick with glasses, use the AR coating since more light seems to help you.

PRK, as delivered to you ten years ago, is not the same as today's PRK since the post-procedure medical treatments rendered today help reduce the scarring. More is known now about how the cornea heals.

Two more things: (1) How centered are your ablations on your corneas? A de-centered ablation can compound your vision problems and their potential solutions. (2) A legitimate RGP fitting is diagnostic. It gives the fitter and the patient insight into the nature of your problem and the underlying refractive/accommodative instability.

How does once test to see how centered your ablations are?I'm wondering if this could have any bearing on my dizziness etc.

Topographies can show if your ablations are de-centered. Not all people with de-centered ablations experience dizziness and certainly there are those with well centered ablations complaining of dizziness. Distorted vision and underlying binocularity (coordination) problems can be exacerbated by refractive surgery and are more likely to be causing dizziness.

One concept that RS casualties and their doctors need to grasp is that RS complications are frequently due to a combination of things, not just one factor. A patient with strong and stable binocularity may be more likely to tolerate de-centered ablations and HOAs than someone whose pre-surgical binocularity is frail. Having 20/20 does not guarantee good vision any more than having ten toes guarantees walking.

Hi Doctors - or possibly Dr Hartzok

Hoping I can get some more advice. Ive come a long way since original postings. I have managed to eliminate 70 per cent of my problems by having an impacted wisdom tooth removed! (My brief theory is that I tensed facial muscles in poor light due to vision, which aggravated the tooth, which was lying against my main facial nerve) as with most things doctors insist this could not be the case but time will tell.

Anyway vision is still an issue and I still feel tension pain in so many different lighting. I am extremely lucky to be receiving the help of a hospital optometry unit in the UK - they have tried every soft lens known to man and beast. I cannot tolerate any of them and when I visit again they will be trying there last pair! I know soft lens overcome the problems for me but cant get past the tolerance problems.

The hospital has no practical experience of RS induced problems and neither have any of the opticians locally (although they would like me to spend a lot of cash before admitting this.)

The head of optometry has shown exceptional kindness and perserverence though and if I can find any possible solutions myself she may help.

Can you advise on any soft lens you have faith in. Are you able to give any positive feedback on the Boston Scleral lens that I keep reading about. How does this work in comparison to other lenses and where has it proven more beneficial.

Why do you think it might be that I am constantly aware of the outer peripheral of the lenses - it feels like my eye lid drags over the lens and the lens jumps about. They say there are only 3 fits to soft lenses and I have the right fit! I realise my eyes are very dry and I am using solutions to address this (without preservatives) but I feel there is more to it.

Previously I discussed using pilocarpine with you. For some reason all medical types here reject as the side effects are very grim - In your experience do the benefits outway the risks.

Finally anything you can think of that I haven't?

Always extremely grateful for your time and kindness.

Debbie

"...they have tried every soft lens known to man and beast. I cannot tolerate any of them..."
"...I am constantly aware of the outer peripheral of the lenses - it feels like my eye lid drags over the lens and the lens jumps about. They say there are only 3 fits to soft lenses and I have the right fit!"

The lenses don't fit. The lenses they are attempting to use were not designed to fit a cornea that has undergone the alteration made by refractive surgery. If you had 1/3 of your foot amputated, could you wear regular shoes? Of course not. You feel the edge of the lens because the center of the lens is being forced onto your flattened cornea, raising the edge of the lens under your upper lid. Someone who had a minimal amount of refractive error before surgery may be able to tolerate regular soft lenses, but obviously that is not you. BTW, there are more than three fits available in soft lenses but as the amount of corneal alteration changes, the chances of getting a soft lens to work decrease markedly.

"Can you advise on any soft lens you have faith in."

For all the of reasons above, no. If fixing the complications of refractive surgery was a matter of finding the right soft lens, then you and a lot of other people would have been fixed already. You lost a chunk of each cornea. Your corneas are not like anything nature ever doled out. If you were the only person to have ever had refractive surgery, your corneas would be considered an extreme anomaly, a scientific curiosity, an oddity. Most doctors seem oblivious to this concept of corneal surface modification when it comes to fitting lenses. They start throwing lenses at RS patients like a naive shoe clerk pulling shoes off a rack, hoping to fit that partial amputee. Round pegs are meant to fit round holes, not square ones; that's an easy concept. For some reason, regular contact lenses NOT fitting a post-RS cornea is a difficult concept.

There are specialty soft lenses for post-RS patients but I don't know of one that has been consistently successful. Patients with great CL success are quick to tell others. Unfortunately, one patient's success has not translated into others' success. Post-RS corneas are unique to each patient. Customization is usually required and that is where the system breaks down.

"Are you able to give any positive feedback on the Boston Scleral lens that I keep reading about. How does this work in comparison to other lenses and where has it proven more beneficial."

Scleral lenses are only as good as the fit. Scleral lenses are about the same size as soft lenses and even larger than many soft lenses. Their rigidity can improve vision by covering the entire cornea with an optically regular surface. The difficulty is in the fitting and wearing. Because they are so large, the conjunctiva may not tolerate long wearing times. Like every specialty lens, the key is whether the fit can be optimized to be tolerated physiologically.

"Why do you think it might be that I realise my eyes are very dry and I am using solutions to address this (without preservatives) but I feel there is more to it."

Corneal refractive surgery alters the corneal nerves - nerves that tell the brain about dryness and discomfort. Presumably, the nerves regenerate but studies show that not all nerves regenerate. I personally think that post-RS dryness is not physically equal to normal dry eye. Non-RS patients who wear snug fitting soft lenses often complain of dryness. This is pretty common, even in young people in their teens and twenties. These patients rarely ever complain of dryness when they are not wearing lenses. If we prescribe better fitting soft lenses, many will report that dryness is no longer a problem. We altered the fit of the lenses and altered their symptoms. Many patients with RS report dryness who never had symptoms of dry eye before surgery. Obviously, in both cases, the cornea's physiologic condition has been altered.

Dousing a snug-fitting soft lens with drops does not affectively alter the cornea's physiology or the drops would provide relief. Dousing an RS cornea with drops does not affectively alter the cornea's physiology or the drops would provide relief. In both cases, dryness is the complaint but the circumstances are completely different. Drops don't work well in either case. We are likely to solve the CL dryness by altering the fit; we can remove the causal agent. We can't remove the causal agent in RS dryness. All we can hope for is that some researcher, in a moment of enlightenment, discovers a way to relieve the physiologic condition of corneal RS.

Hi Dr Hartzok

.I have now visited the hospital again. With regard to the Scleral lens the hospital optician has given me a lens that covers the whole of my eye including the white. (she says they are usually used for people recovering from glaucoma ops). Would this be the same as a Scleral lens as you described: -

(Scleral lenses are about the same size as soft lenses and even larger than many soft lenses. Their rigidity can improve vision by covering the entire cornea with an optically regular surface)

This lens sound bigger to me and to tell you the truth it is near on impossbile to get it into my eye.
The optician is next going to try a reverse geometry RGP lens (although I have very bad pre surgery memories of RGPs)

[quote]There are specialty soft lenses for post-RS patients

After this she would be out of ideas but she has agreed to try to obtain contact lenses that are specifically designed for RS patients as you described. Can you give me the names of such lenses along with the name of the manufacturer(s).

Hope you can help - as I said previously there is not a lot of experience in this field - were I am a patient.

quote:

There are specialty soft lenses for post-RS patients but I don't know of one that has been consistently successful. Patients with great CL success are quick to tell others.

Hello Dr Hartzok

Previously I asked you to provide the name of these 'speciality contact lenses' and I was moved onto a private topic board. Barbara responded and stated she had been in touch with manufacturers and there were no new materials.

My question still remains. What are the make and names of these speciality contact lenses? If there are not any then I would appreciate it if you could let me know and I can cancel out that lead so to speak. I have very kind staff at the hospital on 'standby' prepared to make enquiries if I can come up with some product names.

Also I wonder if you could help with a question I have with Scleral lenses. (Briefly) You may recall I live in the UK and I am getting help from a local hospital with the problems I have. My vision has regressed to approx -1.00 (another problem the RS salesmen forgot to warn against!) So I really need contact lenses now to overcome refraction issues and the loss of visual acuity. I have been trying a Scleral (soft lenses) I think the hospital usually use it for people who have had surgery to hold the cornea in place. Anyway I really struggled to insert it but I have found that it is not as uncomfortable as I expected it to be . In fact the problems with normal soft lenses were not present . i.e The feeling of the lens getting caught against the rim of my eyelids .

The problem is though these lenses were huge, I had an air bubble were it was lifting out at one end of my eye as it was too big. I could not get a clear image and I am hoping this might be as the fit was so out. Can you tell me if scleral lenses can be adapted to fit if they are a soft lens and also can they have a prescription to correct myopia? Hopefully this might be the lens for me after two years of getting nowhere slowly.

Thanks for your help as always

Debbie

Debbie:

The lens I mentioned in the PM was called TRIPLA XL.

I was unable to find any other information regarding this lens, other than the patient was fitted with it in Europe. None of the ODs I queried was familiar with it. It is possible that in the translation, something was lost. Perhaps it is only available in Europe.

Debbie,

I wanted to refer you to a specific thread that Barbara was able to locate with ease.

There is a response in this thread about fitting rigid contact lenses on post-ablation corneas. The number one thing that patients think is that RGPs for post-ablation corneas are "branded" - that all you need to do is get the right brand. If it was that easy, we would just post a banner for the brand and refer everyone to a company's web site. Your situation is unique to you. No one else has your corneas and no "brand" is the answer. This is custom work. For as long as I have been posting to this BB, there has been one continuing question: "What brand works best?" Doctors are always looking for THE brand. Patients are always looking for THE brand. If is was that easy, we wouldn't have any difficulty building a network of fitters.

Go to the below referenced thread. Read about the design. This is what works for me. Dr. Maller in Florida can do wonders with WAVE lenses. But there is no "WAVE" lens; there is only the WAVE software that he uses to help in the initial design of the lenses. Every doctor using that technology does not achieve the success that Dr. Maller achieves because it still requires customization. Essentially, patients get "Dr. Maller's post-ablation, WAVE software-assisted RGPs" which is not exactly the same as "Dr. _ _ _ _ _ 's post-ablation, WAVE software-assisted RGPs", even though they use the same software as a starting point.

What I do is what my experience has taught me and, certainly, not what any school or contact lens CE course can teach. This is the problem with getting help. Some patients are easier to fit than others and whatever "brand" works for someone, they presume that "brand" is the answer for others. By and large, this has nothing to do with brands but being able to adapt lenses to the individual patient's situation.

http://visionsurgeryrehab.evecommunity.com/eve/forums/a...001064703#2001064703