C3R - Corneal Collagen Crosslinking!

[jayuk]

Years wise I cant say; this is only information that I have recieved in email so take it with a pinch of salt.....until its added to proper research its really hard to confirm anything in all honesty.

[GarethB]

The research is still going on as it is a long term study, so it could well be that the data Jay has been sent by e-mail is incomplete in that the study has yet to reach its conclusion.

The data I have obtained which is part of a long term study that has a few more years to run implies a couple percent.

As Jay says, take this with a pinch of salt as the data needs to be analysed in its entirety and checked too prior to publication. This is not just to do with proffesional reputations, but because the implications reslts from any study like this will have for patients, both positive and negative.

[Act44]

Thank you very much for your answers.

You say "a couple percent", can you say in what study it took place.

I have read the study of Theo Seiler and Kolkaas (11/2005) and no one had regressed, but they had removed the eptihelium and the pachymetry was always upper than 400 um. Has it changed since the publication in 11/2005 ? Do you talk about another study ?

Sorry to insist, but it's important.

THANK YOU VERY MUCH ! IT'S REALLY VERY NICE.

Bye

[GarethB]

Hi Act,

Do not have a study name, I was just sent a set of numbers which I did my own data analysis as I work in the healthcare business.

To the best of my knowledge the data has not been published before. It is most definitly another study.

Sorry I can not help further.

Unfortunatly I do not see any treament as ever being 100% succesful, even if there is a 1 in 1000000 chance of something going wrong I would like to know what the risks are. That might just be the researcher in me.

[jayuk]

Act44

Again, its not study but rather comments in email......it would appear that the information from USA and information from Europe kinda contradicts......the study which you refer to is kind of dated now....as thats the first one that many around the world used last year and on its publication.......I would suspect that over the next 12 months we will get alot of information from the UK where this procedure has taken place......this will be extremely valuable as I am led to beleive that majority in the UK only perform this WITH the epithleium in place.

Interesting times!

Jay

[GarethB]

One problem I always have with publications in journals is that there is relatively limited space for all the information to be put across.

So although data between Europe and US appears contradictory, without a copy of the full report including the study protocols for each it is hard for even the profffesionals to spereate the wheat from the chaff so to speak.

As there is a KC confrence in 2007 (seperate topic) perhaps more of the C3R reports from the US and Europe will be put into a better context.

[Act44]

Thank very much for your answers. I'm sorry to ask so many questions to you ! and I admire your cordiality to answer me. So a big thanks !

When you say there is an inconsistency between USA and Europe, it is about the efficiency of the process with an epithelium in place or about the efficiency about the process whatever the method ?

I have talked to some people in Internet and it seems, at Dresden; they keep announcing that the effect lasts at least ten years with an epithelium removed and in 100 % of cases.

So, it would be well if you could have more precisions before the X linking congress which is in December 2006.

If you have more recent studies or articles than the one of 11/2005 from Kolkhaas. Don't hesitate to post it. I am extremely interested.

I want to repeat: thank you very much for your help.

[jayuk]

Act

I would suspect that the KC conference that Gareth was reffering to will also be a place where C3R will be debated and discussed......I do still know that many UK Opthamologists are split 50-50 on C3R effectiveness and thus it has not been taken up as much as say Germany and USA.

However, we wait and see......

J

[Andrew MacLean]

Act

There was a great deal of excitement about C3R. The theory seemed to stand up. On observing Keratoconic corneas it was evident that the stroma (the 'bulk' of the cornea) was short of collagen. The theory goes that if you can replace the collagen the cornea will resume its 'natural' thickness and become healthy again (I summarize).

The human body has many different sorts of collagen, not all of which are found in the stroma of the cornea.

One of the collagens is the common vitamin riboflavin. If the eye could be persuaded to take up Riboflavin, then the bulk of the cornea might be restored and the progress of KC either halted, slowed or reversed.

Tests were done to see if the theoretical possibility could be made a reality.

Tests moved into human subjects. Sometimes the layer of surface cells from the eye of the recipient were removed, sometimes not. Riboflavin was administered by means of drops and then 'fixed' in the eye by the careful use of UV light.

The problem was that although the theory seemed good, the results did not always live up to expectations. with new medical procedures, this is very common. the next step was to see whether the times when the results and the expectations did not match could be explained within the general theoretical framework, or if the theory itself was flawed.

This is where there is now some debate within the world wide community of ophthalmologists.

[Lynn White]

The frustrating (and actually exciting thing) is that research often brings up more questions than it answers.

There is no procedure in the world that can claim to be a 100% effective, as in you are guaranteed success in the way you want it. Take laser surgery. A success from the point of view of an ophthalmologist is that your vision is very much improved to what it was before measured WITHOUT glasses or contacts. Success from a patient point of view is that vision is the SAME as contacts or lenses without having to use either. Subtle difference.

So it all depends on what C3R 100% success actually means. If it means there was some regression, then yes maybe all the procedures were 100% successful. If you are talking regression that is stable after 5 years... then the percentage maybe much less and you have to wait that long to get the results!! And we haven't even got into what happens after 20 or 30 years with an eye that has been treated with C3R.

Going back to laser surgery - a patient of mine I saw recently had undergone lasik (and corneas were very cloudy I have to say) but now had a problem where the lenses of his eyes had broken loose (subluxation). He was in the process of being assessed for extraction of the lenses and implants. (Like when you have cataracts and have them removed and replaced with plastic implants)

The consultant was talking to me about it, as we were trying to assess what his refraction had been excactly before the procedure. "You know, this is going to be an increasing problem as time goes on.. " he said thoughtfully. "Becasue without accurate figures of previous refraction, trying to calculate the power of the implant is rather like sticking the tail on the donkey!"

So you see each new procedure can have a knock on effect on other procedures and ocular health in the future - some of which effects may not become apparant until years and years later.

Lynn!