dioptres after graft

[tommy11]

I cant seem to find to much on the net regarding what dioptres to expect after a graft.
I currently have 13 dioptres in the worse eye and was wondering what the typical amount is post dalk/pk?

[gsward]

I think it would be difficult to generalise about this as there are so many factors. It depends on the curvature of your cornea, your own natural 'lens' and the internal length of the eye. Before my graft I needed about +6D to be able to see distance.

After the graft I needed about the same lens (but scleral) but all the distortion was gone. So the answer to your question, mine was pretty much the same.

Subsequently, I developed a cataract that needed to be fixed. Before that operation they carefully measured the internal length of the eye to calculate what lens to insert during the operation. I ended up with +33D, but now after everything is settled I can see distance unaided (about 6/9) and can read unaided too. A very good outcome for me.

Graham

[tommy11]

Hi Graham, what you have said is quite surprising and shows how little I know about this, I've only had it 15 years!
I have always thought the higher the astigmatism (dioptres) the worse my vision will be. and if I have a graft, the aim is to get back down to as close to zero dioptres as possible?

[gsward]

It's a difficult subject to generalise and answer a questions like, 'what's normal and what is acceptable vision?' In the early stages, KC is often missed and diagnosed as astigmatism, but as the KC progresses it is easier to understand what is happening. The main tool used for diagnosis is the topography or 'Pentacam'. This is a useful article which just scratches the surface of this complex subject.

[Anne Klepacz]

Tommy, I've had KC for a lot longer than 15 years, and there's still things I find really confusing. Like the fact that shortsightedness and longsightedness are measured in dioptres (that's the figure in the first column of an eye prescription which is labelled Sph) but astigmatism, which is indicated in the next column labelled Cyl, is ALSO measured in dioptres. So your 13 may be measuring your shortsightedness rather than your astigmatism. But as Graham says, what happens post graft varies from one individual to another. The outcome, though, is almost inevitably better vision than before the graft, though it may take a while to get there.

[tommy11]

Thanks for the article Graham, its quite friendly written, I've learnt a lot.
The 13 dioptres I am referring to is my astigmatism value from the pentacam. Its the only figure from the pentacam I have really kept an 'eye' on over the years.