From: king@reasoning.com (Dick King)
Subject: Re: Can't wear contacts after RK/PRK?
Keywords: radial,keratotomy,contact,lenses
Article-I.D.: kestrel.1993Apr16.172052.27843
Organization: Reasoning Systems, Inc., Palo Alto, CA
Lines: 22
Nntp-Posting-Host: drums.reasoning.com

In article <1993Apr16.063425.163999@zeus.calpoly.edu> dfield@flute.calpoly.edu (InfoSpunj (Dan Field)) writes:
>I love the FAQ.       
>
>The comment about contact lenses not being an option for any remaining
>correction after RK and possibly after PRK is interresting.  Why is
>this?  Does anyone know for sure whether this applies to PRK as well?
>
>Also, why is it possible to get a correction in PRK with involvement of
>only about 5% of the corneal depth, while RK is done to a depth of up to
>95%?  Why such a difference?

In myopia the cornea is too curved.  There is too much of a bulge in the
center.

In PRK the laser removes a small amount of material from the center.

In RK the surgeon cuts incisions near the edge.  They heal, and the scarring
reshapes the cornea.

Entirely different mechanisms, and the action is in a different place.

-dk
