Devastated KC sufferer did Cross linking

[longhoc]

Hi Grim

Many thanks for the additional information. And the article (Corneal topography indices after corneal collagen crosslinking for keratoconus and corneal ectasia:
One-year results) too was very informative. In terms of what it means for you, the optometry stuff went way over may head unfortunately. But the statistical analysis did not. It’s important when presented by such a wealth of data to be aware of what it shows and what it doesn’t. It’s very tempting, and dare I say, you might have ended up inadvertently doing this, to take a hypothesis and then look into the data points to find “proof” for your idea. I’m not being judgmental here, we all do it, all the time (even those of us who should know better !)

The questions you’re asking yourself is, “should I believe what the professional says when they tell me I should wait a year post crosslinking ?” Taken overall, the study data shows that the answer is, unequivocally, yes.

You’re entirely correct to say that the ISV index doesn’t show a statistically significant change in the period from 6 to 12 months when looking at all participants in the trial. Note though, there is a considerable amount of noise in the sampling (123.8 +/-56.6 in the baseline, 113.3 +/-56.7 at 12 months – without looking at each individual participant’s results which would run to about 50 pages of raw data, it is possible that there was a fair amount of deviation from the mean). But, ah-hem, most importantly, you can’t exclude the results for IHA (index of height asymmetry). This index shows the largest degree of change in the period from post 6 months to post 12 months of all the indices. IVA (index of vertical asymmetry) also demonstrates continued significant change in this period (although the rate of change has slowed c/w post 1 month to post 3 months).

What this means for your vision, that I am not qualified to comment. What the person who is looking after you in the clinic is telling you though, evidenced by the data, is that it will take 12 months for the eye to stabilise postoperatively. You might well not be able to go from, say, 20/100 to 20/20 in the next 6 months with glasses. That isn’t the reason for waiting. The reason for waiting is to get to a reasonable certainty that your eye is then stable. Looking at the data we’ve got, I can’t conclude any other way and I guess that your consultant can’t either.

Okay, what about your vision then. Glasses may well be out due to the residual irregularity of your cornea – so how do you feel about a contact lens ?

In terms of the other options, it could well be your cornea is too thin. For Intacs and laser procedures (maybe for ICLs as well, I don’t know enough about them so best to check with a professional) anything less that 350 microns of corneal thickness is probably a contra-indication. So the main priority is to start asking some questions about what your corneal thickness is and whether any of these would be suitable for you. You mentioned that you “thought your cornea was too thin” (for laser procedures) – be really good to find out for sure, if you’ve not already done this. It’s not something you can guess yourself, it needs measuring with specialist equipment.

Finally, thinking about the “was it (crosslinking) the right thing to do” question, I can only relay my understanding of clinical best practice. If as you say your cornea was thin (say, between 350 and 400 microns, especially if it was at the lower boundary of that range) and your Keratoconus was progressing and your age profile is in your twenties or early thirties then absolutely you were indicated for crosslinking. If this was the situation, and the Keratoconus was actively progressing e.g. you were losing 5 to 10 microns thickness per year or more, you’d have been very fortunate to have been able to hang on to good vision with glasses in the long term.

Please do let us know how you get on

Best wishes

Chris

[Lynn White]

Grim

To help you make sense of this we need more information.

Can you tell me:

Were you wearing contact lenses before the procedure? Has anyone tried contact lenses since the procedure?

Did you have the cross linking epi off or epi on?

Did you have any other procedures done at the same time?

Do you have any corneal haze following the procedure? If you do, what does your consultant say about it?

I have seen CXL cause disruption to vision for many months following the procedure -this depends very much on the past history of the patient and the state of the cornea at the time of CXL.

My advise is that, if you are in any doubt, you need to consult another ophthalmologist. We on these boards cannot know your full history which is why, in truth, many have not replied to you. Everyone is an individual as far as this condition is concerned and there may be circumstances unique to yourself that may be affecting your outcome.

Lynn

[Grim10]

Grim

To help you make sense of this we need more information.

Can you tell me:

Were you wearing contact lenses before the procedure? Has anyone tried contact lenses since the procedure?
No havent weared contact lenses att alla, tried it several times (different ones) but cant tolerate.

Did you have the cross linking epi off or epi on?
Not sure what you mean, try to google it. No Intacs have been involved if that is what you mean

Did you have any other procedures done at the same time?
No

Do you have any corneal haze following the procedure? If you do, what does your consultant say about it?
Yea some haze but he says it usually will resolve within one year

I have seen CXL cause disruption to vision for many months following the procedure -this depends very much on the past history of the patient and the state of the cornea at the time of CXL.
Alright.

My advise is that, if you are in any doubt, you need to consult another ophthalmologist. We on these boards cannot know your full history which is why, in truth, many have not replied to you. Everyone is an individual as far as this condition is concerned and there may be circumstances unique to yourself that may be affecting your outcome.

Lynn

[Grim10]

Soon I am 7 months post op and still no change in visual capacity