Pain directly related to lens wear.

[Michael P]

Hari, forgive me if I am being dense; I must confess I haven't followed all your posts on this subject.

Am I right in saying that your view is that more research needs to be done into the effects of lens wear rather than we shouldn't be wearing them at all.

Obviously, at present, for many of us, lenses are the only path to improved vision. I have always understood that there are risks involved with wearing RGP's but have taken the view, in my case, that they are far outweighed by the benefits.

[Hari Navarro]

Thanks guys for your comments...
It funny how we both see this issue from completely different perspectives...

Thanks for posting that, Hari.
It's useful to see their suggestion that the use of lenses does not cause scarring.

Although the 'Contact lens-induced corneal epithelial injury.' article was intended by its authors to show that as far as the medical profession was concerned no decernable scarring (thus no damage) actually occurs... I saw the report from a Kcer's perspective - the line 'although it causes deep corneal abrasions' spoke directly to the fact that trauma WAS in fact being inflicted by lenses (no matter how deep) and that this surely has an effect on the way Keratoconus evolves.

Recently a friend of mine attended a KC conference held by respected eye surgery professionals, he posted this insight on another forum:

The Epithelium is very clever...why?

If in the advent of an assault happening to the cornea through an abrasion, "dent", refractive surgery complications, etc... The Epithelium compensates itself, by getting thinner or thicker to keep the outer-surface the same, in the round shape as it always has been.
(but this only works to a point)

The other thing I saw the Epithelium can do which is clever, (on a picture on an over head slide) was the ability to "ride over" a "dent" on the cornea, like a "bridge" or a highway "fly-over", in that just "flying over" the problem area, to keep the cornea round, when possible.

So what does this mean to us?

It means that "dents" to the cornea caused by hard contact lenses by various degree's in abrasions/friction/rubbing which in turn causes vision to decrease - this HAPPENS without the Dr/fitter knowing why?... the fitter/Dr may "think" the abrasion has healed and all is well and back to normal (but the Epithelium is masking the "dent") and so they end up wrongly blaming it on your Keratoconus if your vision has got worse, when in reality they are ignorant to the fact's about the Epithelium being very clever... as already mentioned, and they have not got the equipment needed to look for this.

Vision may be still be readable at the same point on an eye chart, but with contrast and clarity going down, with wave-front analysis for example of a transplanted cornea and what can be seen from it, it was seen to be very poor due to the light not passing throught it on a straight path, there was abrasions, lots of them in the way... so when someone says they can read so much of a eye chart, in reality the vision they have is a poor quality one in what they can see.

When Corneal Topograpgy is used to "diagnose" KC, it is only an indicator that KC is present and so strictly speaking it can not diagnose Keratoconus.

This is because the Epithelium "masks" the development of the cone pushing to come out on to the surface. This is very very important in laser surgery, but alas this thinking is not known... hence "Keratoconus post laser" is the result!! (kera-elastia)

In summary-The Epithelium is very clever, no one knows how it knows when to ride over/mask problems. But detailed examination of it does give us a true diagnoses - making any laser surgery fool proof.
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I personally beleive that if lens wear was so damaging that we would be see far higher cases of corneal transplants regardless of people having KC as we form only a small minority of the overall lens wearing population.

I'm not saying that contact lens wear is a direct line to graft. I'm asking about the possibility that it contributes to the complex evolution of keratoconus.
The damage does not have to be great for this to effect our already compromissed corneas. This damage may effect other eye diseases in varying ways... my point again is shouldn't we be asking for a review to decipher exactly how?

I believe many contributing aspects make up the recipe that eventually becomes keratoconus... enviromental elements, physical contact ie: eye rubbing, perhaps a genetic aspects etc ... I do not see how contact lenses worn against one of the most fragile membranes in our body cannot have a negative effect.
And no matter how large or small this effect can we really totally rule out that this doesnt at the very least 'trigger' any one of the other elements to further damage?

The African sub-continent is often held up as an example of why contact lenses cannot be the sole cause of KC, as many there do not access to them to the same extent as we. (Again I do not say that they are the sole cause but only an ingrediant) ... I have read recently that certain studies have shown that those of African decent, living in these areas, have shown to have significantly thinner corneas than other areas of the world regardless of KC.
Some unknown factor... be it genetic, nutritional or enviromental has made this the case. So it may be that comparing the two as lens wearing keratoconus models is invalid.
So a weakening has occured whatever the cause... I wonder what would be the result if these African patients did in fact wear lenses long term? Those of us who live in so called developed countrys also 'for some reason' have thinned corneal tissue and in our particular case this presents as keratoconus. But also in our case we insist on offering the chance of further disruption with the use of lenses.
I may be very, very wrong but shouldn't we at least attempt on some scale to uncover exactly what this percieved 'minimal effect' is having? Instead of finding innovative ways to mask it.

Hari

[Hari Navarro]

Hi Michael,
I just caught your post... I'm saying that the we as KCer's are for the most part cornered by contact lenses in that we feel we cannot function ie: do our jobs etc without them.

Many feel as you do that the trade off is well worth any minimal discomfort and damage.
But I'm saying that also many, if any, of us do not know exactly what this effect is having on our long term keratoconus progression. If we did then we may be less inclined to mask the problem and more likely to push for alternative options.

To be honest with you no matter what the benefit I still see lenses as invasive. But I also believe that education is the key... many are not as informed as you in that many are not presented with the facts before fitting so they can decide on weighing up the pros and cons on a personal basis.
Regards,
Hari

[jayuk]

Hari

Interesting post, but what has been missed; and not intentionally, is the rate at with the epithelium heals. Its meant to be one of the fastest healing tissues in the body and Id suspect that this healing process and its outcome, could also be what your term "masking" ? Again, maybe another reason why eyes should be gives a break every week for CL wear......

J

[Hari Navarro]

It may very well be the fastest healing tissue in the body but how many times are we, as a contact lens wearing population, to ask it to do this in our lifetime? And to what effect?

Its healing because its damaged or contorted in someway how can this in anyway be a positive?

Giving our eyes a break every so often before again submitting them to the indications of lens wear is fine - but isnt the fact that we have to do this in itself indication that some possible lasting 'effect' is indeed taking place?

Pre lasik we are asked to remove our lenses some weeks before surgery to allow our corneas to return to their natural form... this delicate tissue is being reshaped and oxygen permiation is being hindered (which is another topic in itself... we are told that certain lenses allow 'enough' oxygen to reach the corneal surface... but what does the cornea itself regard as sufficent? To my mind the cornea is a very finely tuned machine and the upsetting of this natural balance must also have effect... as far as I know human tissue is the only substance that can properly transmit oxygen).

Basically all I'm asking for is that someone provide us with the data that shows us that lenses have no effect of KC progression. If it turns out that they do then all I'd say is make this information mainstream so we can all make informed choices when deciding on a treatment path. Its not good enough that we have to feel that lenses are the ONLY assessable option available.

Like I said to Michael, in any trade off you have to know exactly what it is you are trading.

Hari

[Lesley Foster]

Hari,

Are you saying that given the choice we should opt out of wearing contact lenses and have surgery instead?

I for one am grateful that I can wear lenses, there is no way I would choose to have any operation on my eyes unless it was absolutely necessary. To me that option is the final one and the longer I can manage with lenses the better. If my eyes start to get sore I remove my lenses which leaves me virtually blind because I cannot resort to glasses as a backup but I find that preferable to having surgery which may not work.

Lesley.

[Hari Navarro]

Hi Lesley,
No... I am in no way suggesting that anyone should opt for any particular treatment (especially graft).
All I am saying is that 'If' contact lenses are found to contribute to Keratoconus then we have to be fully informed of such. And we should then be encouraged to access all that keratoconus treatment has at hand... with the intention of maybe finding another path through KC that fits with our personal requirements. All alternative options are not strickly surgical...

How many contact lens specialists have for example offered their patients information on collagen cross-linking for the treatment of KC. This, apart from an epithelial scratch, is not a surgical operation and yet it is showing excelent results. Its an option... one to be considered (among) others... no more no less.

I advocate nothing more than full education as to what it is we do to our eyes when we go through our daily contact routine. You personally are grateful to them as they allow you to see... where without you have difficulty... but if (and I stress if) they are found to contribute to your KC then isn't it of utmost importance that we find out now what the long term prospects may be?

To me the scary thing is not the consideration that lenses may effect KC its the not knowing either way.

Regards,
Hari