| Bryce Carlson 2005-01-27, 8:52 am |
| Not necessarily true, Rags. Although I agree that with LASIK the 250 um RSB
rule is sufficient in healthy eyes, your analogy to RK does not hold up.
The deep radial incisions in RK *do* cause ectasia. That's the whole idea.
The intent with RK is to induce a controlled mid-peripheral ectasia that
effectively flattens the central cornea, reducing or eliminating the myopia.
However, one of the big problems with RK is that the ectasia often (~40% of
the time) does not stop with the intended initial mid-peripheral bulging.
Instead, it often slowly progresses year after year resulting in what is
called "creeping hyperopia." Many, if not most, previously myopic RK
patients eventually end up hyperopic due to this process. This is a
fundamental flaw in the RK procedure that has never been completely
eliminated.
Bryce Carlson
"Ragnar" wrote in message news:
> (snip)
>
> Incidentally... in the Radial Keratotomy procedure, the slits are made
> to a depth of 95% to 98% of the cornea... which leaves only 10 microns
> untouched. If one's eye isn't falling out of their head with just
> 10 microns untouched... certainly 250+ microns isn't going to be a
> problem.
>
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