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the task. While the risk of serious vision-threatening complications
after having LASIK is low
(< 1%), some complications
could have a signifi cant impact
on visual performance in a
cockpit environment.
Relative Risk of Post-Surgical Complications:
4 Prolonged healing periods: 3 months or more
4 Night glare (halos, starbursts): 1 in 50
4 Under/over-correction: less than 1 in 100
4 Increased intraocular pressure: non signifi cant
4 Corneal haze: 1 in 1,000
4 Corneal scarring: non signifi cant
4 Loss of BCVA: 1 in 100
4 Infection: 1 in 5,000
4 Corneal fl ap complications (dislocated fl ap, epithelial ingrowth):
less than 1 in 100
Following LASIK, patients are cautioned to avoid rubbing their eyes
and to stay out of swimming pools, hot tubs, or whirlpools for at
least a week. Contact sports should be avoided for a minimum of 2
weeks, and many eye surgeons recommend wearing safety eyewear
while playing sports. Even after the patient’s vision has stabilized and
healing appears complete, the corneal fl ap may not be completely readhered.
There have been reports of corneal fl ap displacement due to
trauma up to 38 months after the procedure.
After surgery, patients are cautioned to not wear eye makeup or use
lotions and creams around their eyes for a minimum of 2 weeks and
to discard all previously used makeup to reduce the risk of infection.
In some instances, LASIK may be an option for patients with higher
refractive error than can be safely corrected with PRK or those with
conditions that can delay healing (e.g., lupus, rheumatoid arthritis).
Since LASIK minimizes the area of the epithelium surgically
altered, it reduces some of the risks associated with delayed healing.
Additionally, ablation of the underlying stromal tissue results in less
corneal haze and the tendency for the cornea to revert back to the
original refractive condition during the healing process (refractive
regression), which improves predictability. Most patients do not
require long-term, postoperative steroid use, decreasing the possibility
of steroid-induced complications (cataract, glaucoma).
As with any invasive procedure, there are surgical risks, and the
recovery process often varies with each individual. Post-LASIK
patients report experiencing mild irritation, sensitivity to bright light,
and tearing for a few days after surgery. For most, vision stabilizes
within 3 months to near-predicted results, and residual night glare
usually diminishes within 6 months. In rare cases, symptoms have
lingered longer than a year. Earlier versions of LASIK used a smaller
ablation zone which sometimes resulted in glare problems at night.
Ablation zones have an area of transition between treated and
untreated corneal tissue. As the pupil dilates and becomes larger than
the ablation zone, light (car headlights, streetlights, and traffi c signals
lights) entering through these transition areas becomes distorted,
resulting in aberrations perceived as glare. These patients often
complain of diffi culties seeing under low-light conditions.
Patients that develop postoperative haze during the healing process
have complained of glare (halos and starbursts). Furthermore, it has
been reported that exposure to ultraviolet radiation or bright sunlight
may result in refractive regression and late-onset corneal haze. It
is therefore recommended that all refractive surgery patients wear
sunglasses with UV protection and to refrain from using tanning beds
for several months after surgery.
For those with larger amounts of refractive correction, the
predictability of the resulting refractive correction is less exact.
This can lead to under-correction (requiring an additional laser
enhancement procedure and/or corrective lenses) or over-correction
of the refractive error. In the case of overcorrection, premature
presbyopia and the need for reading glasses can result.
It has been reported that there can be a slower recovery of BCVA and
UCVA with hyperopic LASIK compared with those having myopic
LASIK. This is especially true for older patients who may be even
less likely to achieve UCVA of 20/20 or better. (Note: Loss of BCVA
is reportedly 5 to 15 times more likely with refractive surgery than
from the use of extended-wear contact lenses.)
Older patients with presbyopia may opt for monovision LASIK,
which corrects the dominant eye for distant vision and the other
eye for near vision. The procedure is intended to eliminate the need
for a patient to wear corrective lenses for near and distant vision.
Anisometropia (difference in correction between the eyes) induced
　
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