LASIK can be performed on virtually any
eye; however, sometimes it is not advisable or even permitted. The reasons
for exclusion are legal, medical, psychological, and ocular. It is important
that each person considering the surgery be fully informed as to the
nature and expected outcome of the surgery. Additionally, it is essential
that each perspective patient communicate his/her relevant health information
and expectations to the refractive surgeon.
AGE : It is required by the FDA that
a person undergoing LASIK must be at least eighteen years old. It is
assumed that the refractive error (prescription) of the patient will
be fairly stable at this time. Also, since this procedure is essentially
cosmetic surgery, attainment of legal age is appropriate in order to
provide fully informed consent. There is no upper age limit to LASIK
eligibility; neither does it affect the nature or outcome of the surgery.
ENDOCRINE : Hormone fluctuations can
affect the refractive error of a person's eye. Surgery during a period
of such instability would probably produce changes which would not
be correct once the endocrine system returns to normal. Therefore,
LASIK is not recommended for women who may be pregnant, nursing, or
undergoing changes in oral contraceptive therapy.
HEALTH : The cornea is composed of a
matrix of collagen fibers, the same material which comprises tendons
and other connective tissue. Therefore, persons who have autoimmune
disorders, e.g., rheumatoid arthritis, Sjogren's Syndrome, Systemic
Lupus Erythematosis, etc., may be at risk for unpredicted changes following
surgery. Other medical problems, such as diabetes mellitus, high blood
pressure, heart problems, etc. do not affect the outcome of LASIK surgery.
PSYCHOLOGICAL : Awareness and acceptance
of less than a 'perfect' result is essential prior to undergoing LASIK.
The results of surgery are usually excellent but there is no guarantee
that the surgery will meet or exceed a patient's expectations. The
proper mental attitude for the prospective patient is to expect that
LASIK will substantially improve the uncorrected visual acuity but
glasses may be necessary for some activities.
HERPESVIRUS INFECTION : A history of
herpes simplex infection of the eye may be a contraindication to LASIK
surgery. It is believed that the virus may permanently reside in nerve
cells outside the eye and that any trauma (such as LASIK) might reactivate
an infection. However, this area is undergoing change. Studies are
being done to see if treatment with antiviral medication prior and
after the operation might prevent such a recurrence.Herpes infections
of other parts of the body do not pertain to qualifying for LASIK surgery.
PUPIL SIZE : The excimer lasers in the
United States currently treat an area of the cornea that measures 7
- 8 mm in diameter. Therefore, it is important that the pupil size
be less than the area of treatment. Measurement of the pupil size should
be performed with distance fixation in dim illumination. Most of the
reported difficulties with glare experienced by LASIK patients come
from those with pupillary size irregularities. This picture of the
black pupil is slightly smaller than the largest pupil size eligible
for LASIK surgery...

REFRACTIVE ERROR : Most persons are either
nearsighted or farsighted with some degree of astigmatism. After the
age of 42, people also experienced difficulties with focusing at near — this
is known as presbyopia. LASIK does not correct presbyopia; reading
glasses are a must for older patients following surgery. The range
of refractive errors which can be treated are:
Myopia (nearsightedness) : -0.75 diopters to 10.0 diopters
Hyperopia (farsightedness) : +0.75 diopters to +5.0 diopters
Astigmatism (associated with myopia) : 0 to 4.0 diopters
Presbyopia : no treatment (clinical trials now taking place)
It is important not to confuse 'eligibility' with 'desirability'. LASIK
is a cosmetic procedure which is expensive and may have side effects
and complications. One should carefully weight the plusses and minuses
on a percentage basis, mix in the $$$, discuss the idea with loved ones,
and only gradually make a decision for surgery.