Keratoconus Diagnosis

[GreenEyes]

Hi,

I'm new here and I have a few questions that I'm hoping some knowledgeable/ experienced person here can help me out with!

I'm very short-sighted (about -7 in both eyes) and have been wearing glasses/ soft contact lenses since I was about 10. I'm 23 now. In all that time of going to see my optician regularly, nothing negative was mentioned about the health of my eye. I was told my only problem was myopia. However, I recently went for an intensive examination at the London Vision Clinic in view of getting laser eye surgery there and after all sorts of tests, I was turned away for the procedure. The reason was that the cornea on my right eye was too thin. The surgeon also mentioned something about 'very mild keratoconus' in that eye, as a possible reason for the thin cornea. He told me to come back in two years to see if it has gotten worse and if it has stayed the same then I'll probably be able to get the surgery then. Now that I'm back home and I'm reviewing in my head everything he has told me, and having researched a lot about keratoconus, I'm really confused! I'm unsure if he said that I actually have this condition or if he's unsure as it's its early stages and won't know if I have it or not until I go back again in two years to see if there is any progression.

Really what I wanted to ask you people here is, is there a definitive test to see if you have keratoconus or do you just have to 'wait and see'? The testing I got at LVC was very extensive. All sorts of indepth scans as well as the usual stuff I was expecting so I don't think there is any test that I haven't actually had!

The surgeon said I was fine to continue as I always have with my glasses and soft daily contact lenses, too, which makes me think I don't have this condition... Anyway, thanks to anyone who managed to muddle through that long post and if anyone can offer me any insight then it would be most appreciated!

Thanks!!

[Anne Klepacz]

Hi Greeneyes and welcome to the forum!
In the bad old days, laser clinics didn't have sophisticated equipment to look at the cornea before they offered treatment and some people who'd had laser treatment then went on to develop keratoconus (or laser induced keratoconus). Now that they have state of the art equipment, they find what's called 'subclinical keratoconus' ie KC so mild that it would never have been picked up in the past. And of course they're quite right to say you shouldn't have laser treatment - it could make things worse. But equally it's quite possible that your cornea won't change in the coming years. So relax and follow their advice to leave things as they are and go back in 2 years time to see whether anything has changed. (Of course, if you notice any change in your vision before then, by all means go and see an optician). If LVC can't be sure after all the tests they did whether you actually have KC, I very much doubt whether anyone else would find anything different. With luck, it will stay at the subclinical stage and you won't have any worries.
Anne

[GreenEyes]

Thanks for the reply and the welcome! It has helped me sort it in my head much better!

I just can't help but worry and I feel a wee bit lost and helpless just waiting to see if things develop and, even though I know there's nothing I can do, I feel as though I should be doing something to stop it progressing!

I realise I'm just over-worrying myself but it's hard not to- I think I've scared myself by reading too much- your reply made good reading though!!

[Lynn White]

Hi Greeneyes,

It is likely that if you had never sought out refractive surgery, you may never have found out you had thin corneas and maybe keratoconic "indicators".

I am an optom and am just as shortsighted as you are and I also have very thin corneas and the irony never fails to strike me that I have thinner corneas than many of my own keratoconic patients! Yet I am NOT keratoconic.

The truth is that technology has overtaken diagnosis for this condition. Laser clinics have to be very sure they do not precipitate Keratoconus. Thus any cornea that looks the least bit suspicious has to be rejected as in some cases, refractive surgery on completely normal looking corneas can result in induced keratoconus many years later. Without a visit to a laser clinic, your thin corneas would never have been detected and you could have gone your entire life without it being noticed. Only the fact of being assessed for refractive surgery pointed up the possibility of keratoconus.

If you take refractive surgery out of the equation, you may never have been in a position that your corneal thickness had to be measured. My own thin corneas were only detected when I was trying out some equipment at an exhibition - I had no symptoms at all. We simply do not know how many of the normal population have such thin corneas as there have been no studies to check this.

Keratoconus is a complex condition that is only now yielding up its secrets. I know it is worrying to read all the worst case scenarios but you are nowhere near that position. The fact that you were told to have things checked out in 2 years means that the indicators are very mild. The clinic is being very careful because refractive surgery in itself thins the cornea thus running the risk of precipitating keratoconus. So, a thin cornea means refractive surgery is not advised. It does NOT mean you are going to develop KC.

All the best!

Lynn

[GreenEyes]

I'm so glad I posted here! Thanks Lynn, your reply is very comforting!

I have one more little question though! My right eye, which is the one with the thin cornea, was also identified as being a bit 'lazy'. Even with lenses, I can't see perfectly from that eye alone (I think I can get to the line two above the '20 20' line). This has never been too much of a concern before as with glasses/ contacts I obviously use both eyes to see so it hasn't posed a problem in everyday life, however, is that also another possible indicator of keratoconus?

Thanks again!

[Lynn White]

Ahhhhh!!

That is a very interesting point. I do have several patients whose "lazy eye" show some signs of keratoconus in that even if you correct with contact lenses, the vision does not improve and there are obvious signs the eye has been lazy from a very young age. In theory, KC starts AFTER any of the causes of lazy eye in early childhood and there is no scientific evidence that it begins and then stops at a young age.

However, when you say "even with lenses" do you mean spectacle lenses or contact lenses? Because if its just spectacle lenses, the KC will reduce vision in this way. Vision returns with contact lenses - usually.

One reason for vision still being blurred with contact lenses is that there are other optical surfaces to consider: the back surface of the cornea and the front and back surfaces of the internal ocular lens. These surfaces can be distorted and contribute to reducing vision. I know of a few of my "normal" elderly patients who, after undergoing cataract surgery and having an intra ocular implant, found a lazy eye "miraculously" saw perfectly again. It had been a problem with the internal lens all along, not a lazy eye at all.

Eyes can be quite tricky (and very interesting)!

Lynn

[GreenEyes]

You're right, eyes do indeed seem to be very tricky but also interesting! I feel as though I have learned so much more about my eyes after having all those scans and tests, but that also seems to be leading to more questions!

When I said that the vision in my right eye isn't perfect even with lenses, I meant with contact lenses and glasses- it's never perfect or '20 20'. I only really notice it when I'm getting my eyesight tested with my optician and have my left eye covered up though. In everyday life, I actually see slightly sharper overall with my glasses than I do with my contact lenses... Is this a positive thing? I just wasn't sure if it was coincidental that my right eye is the one with the thin cornea and the 'laziness'.

Sorry for this endless cycle of questions!!

You've been very informative

[Lynn White]

OK...

Well it could be a lazy eye or it could be due to other distortions or it might mean you have not got the optimum contact lens fit, as you say that spectacles give you clearer vision than contact lenses - its usually the other way around with keratoconus!

We are now getting into the position where examining your eyes is the only way to answer your questions. I have often wished on these boards for a virtual slit lamp and examination room as there is only so far you can go with questions and answers! Did you have a squint at all when you were younger?

There is much we don't know about early or sub clinical KC as its never been studied. Interestingly though, because laser clinics have a strong interest in working out which corneas are at risk from laser surgery, much of the research is going on there. Surgeons are looking into epithelial thickness profiling http://www.eyeworld.org/article.php?sid=5304&strict=&morphologic=&query=bausch which may well indicate KC or not even if the topography looks normal. However, until clinicians routinely screen for corneal changes on the High Street, we won't really know how many "normal" people have thin corneas/mild keratoconic changes/ other related issues.

Lynn