What are some reasons someone can be rejected for LASIK eye surgery?
There are many reasons a patient might not be a good candidate for LASIK.
1) You are too nearsighted! There is a direct, proportional relationship between how much myopia (nearsightedness) you want to treat and how much cornea will be removed to accomplish that. Once you go beyond somewhere around -5 to -7 diopters in your Rx, you are getting into risky territory for long term problems.
2) Your cornea is too thin. Just as in the previous example, if your cornea is quite thin, you may not have enough left after some LASIK treatments for long term stability.
3) You have some sort of corneal abnormality. Keratoconus is the most common corneal irregularity among several such conditions that can be made worse by LASIK.
4) Dry Eye. LASIK will unavoidably damage many of the sensory nerves in the cornea while the laser reshapes it. The release of tears from the lacrimal glands occurs when those nerves are irritated. If the lacrimal glands are no longer getting a proper "message" from the LASIK cornea about its drying out, there will be inadequate tear release afterwards. This can be permanent to some degree.
5) You are farsighted, not nearsighted. LASIK does not cure presbyopia -needing reading glasses. While there are ways to "trick" one eye into reading by over or under-correcting it, this is not really a cure. LASIK can be used to treat the other type of farsightedness called hyperopia, but the effect is transient and usually wears off in 2-3 years (unlike the more permanent myopia LASIK).
6) You either have, or are developing cataracts. People over about age 55 will often have at least some degree of discoloration of the natural lens of their eyes. So no matter how well you completely treat any nearsightedness or astigmatism with LASIK, the patient will often experience a result that gets progressively undermined even with an initially good outcome.
_Written by J. Trevor Woodhams, M.D. - Chief of Surgery, Woodhams Eye Clinic