Cross linking prior to cataract operation

[ChrisW]

My optician has just told me I have the beginning of a cataract in my right eye. (The other eye has had two corneal grafts and a cataract op, all done prior to ten years ago). This eye has had keratoconus controlled by a gas permeable lens for 35 years, but my last two check-ups have shown a downturn in the sight with no ability to improve it. The suggestion today was that, if his suspicions are correct and I'll need a catact op, I may need to look into cross-linking for that eye first of all to stablise the cornea. My questions are (1) is this considered essential prior to a catact op and (2) is it true that cross-linking could actually reduce the extent of the keratonconus and, therefore, improve my vision? I'll be going back for another "mapping" and check-up at the end of the year, so would like to understand the importance of cross-linking both in relation to the cataract op and also to the possibility of improving my vision (in addition, of course, to dealing with the cataract). I look forward to hearing your views. Thanks.

[Lynn White]

OK... lots of issues here!

First of all, in theory at least, your cornea should be getting naturally crosslinked with age by now. There are some cases of people with KC starting to progress in middle age and above, but they are not that common. Also, it is probably fair to say most research with CXL has been done on young people, as it is a great tool for slowing/halting rapid progression.

A "cataract op" is very similar to a younger person having an lens implant. The difference is that in a lens implant, an extra lens is slipped in over the top of your existing lens. In the case of a cataract, your own lens is removed and replaced with an artificial one. For younger people with unstable KC and who want to see as well as possible without CLs, CXL is essential as otherwise, the cornea might change shape again, requiring the use of CLs again.

In cataract ops, surgeons attempt to bring your prescription as near normal as possible. As an RGP wearer for 35 years, your cornea will be significantly reshaped by teh lenses and to get a true picture of your real corneal shape, I would imagine you are going to be required to leave your lens out for at least 4 weeks before the op. My experience tells me your cornea will continue changing after that as well. CXL will lengthen this fluctuating period.

Will CXL cause improvement over time? I am not the evidence is there to say one way or another for reasons stated above. For young people, there is a definitely a gradual improvement over several years.

In the end, whether you have CXL or not, the likelihood is you are still going to need a CL to bring your vision up post op, no matter how near "zero" they manage to get your prescription with the implant.

I know this all seems vague but there are no easy answers!

Lynn

[Anna Mason]

Can I just bounce in and say I had cataract surgery but they did not replace the lens as a value couldnt be agreed on so I am undergoing contact lens fittings to fix from the outside.

[ChrisW]

Many thanks to both of you for your input. I'll definitely bear this in mind. With any procedure, of course there's going to be a percentage where things don't work out right and, whereas with both of my corneal transplants in the left eye, there really was no choice (in the first case, it was the vision and in the second case, it was the pain in the eye where the first graft was finally rejecting after 20 years), I'm veering towards the view that cross-linking is probably not an essential procedure for the right eye and so maybe as long as my gas permeable lens is giving me reasonable (though not as good as in the past) correction, I may leave things as they are. In any case, the recommendation was from my optician and to proceed further, I'd have to go through my specialist who I know from past experience is very conservative in his views. I had to fight quite hard to get my second graft rather than stick out simply wearing a bandage lens - whereas the moment I saw Professor Gartry at Moorfields, his immediate reaction was "You've done really well to have a graft lasting 20 years ... it's at the end of its lifespan and you simply need another one." Once again, many thanks for your feedback! Chris