I was just thinking about it just now. I know they remove the
epithelium in PRK, laser your cornea then let the epithelium regrow. If
the epithelium regrows thicker than usual, you regress and end a bit
myopic instead of plano. This is why they sometimes overcorrect you
slightly to allow for regression.

So why not do just the epithelium removal without any laser surgury if
your pescription is very mild or to reduce mild to moderate
pescriptions? I am not sure how much myopia or hyperopia could be
addressed with this method. Id say a diopter is easy with two or even
three diopters possible? This would be great for mild myopes, hyperopes
or to give monovision. Moderate myopes and hyperopes would reduce their
pescription and improve their uncorrected vision threefold, fourfold or
even more!

There may be chemicals that stimulate agressive growing of the
epithelium or to slow down the regrowth so it grows back thinner.
Average thickness is 50 microns. I dont know how much thinning you can
safely do, but I know orthoK can thin it up to 40-50% temporary in an
oblate 6mm zone. Removing the epithelium and letting it regrow would
result in a prolate zone that covers your entire cornea of 12mm.
Perhaps you can thin the epithelium to 35 microns or thicken it to 80+
microns. Its likley youll be able to treat more hyperopia than myopia.
Pupil size would be a nonissue. The risks would be small and no cornea
would be removed, just the epithelium which regrows back in a week or
less.

This will be a blessing for those with mild pescriptions and still
benefit those with moderate pescriptions. Its much safer than laser
surgury. Lasik will stay but itll be used for more severe pescriptions.
Someone with -1 diopters could likley end plano. A -2 may end plano or
if not then 20/25 or 20/30 which will vitrually eliminate glasses
dependancy anyway. A -3 could have his pescription reduced by half to
two thirds and his vision improved around five-fold! May end 20/40 to
20/70 most likley(compared to 20/200 to 20/300) Someone whos -4 may not
experience benefits to the extent low myopes will but he can still
reduce his pescription by a third to half. This will improve his 20/400
uncorrected vision around threefold and get him in the 20/100 to 20/150
range. More than -4 and the amount of improvement will be pretty small
and many may just consider lasik or prk instead for full improvement.
Hyperopes would likewise experience improvements.

Epithelium thinning or thickening can also be used to combat
anisometropia. I know this lady in real life who was -6 in one eye and
-3.5 in the other. Her worse eye was almost three times blurrier. With
glasses, she saw different sized images. She said she was getting
intralase laser in about 3 months to take care of the anisometropia and
of course ditch those akward glasses. Epithelium thinning in her -6 eye
could greatly reduce the anisometropia and it would only have to be
done in one eye. A great alternative if you dont mind still wearing
glasses and not willing to take the risk of lasik but you want to
minimize the anisometropia.

So.........is epithelium thinning/thickening done now or is it in
research as an alternative to refractive surgury?