Is LASIK new?
Yes and no. Historically keratomileusis
has been performed for over 30 years. Early surgery consisted of lifting
a cap of cornea tissue (dissection was done by hand), removing it temporarily
and reshaping the cap to achieve the vision correction desired. The
cap was frozen and lathed to thin it. The surgery was a testimony to
the surgical skill of the pioneering surgeons but the great difficulty
precluded its widespread use.
What did the early
surgery teach us?
Among other things, that the eye could tolerate this surgery - so LASIK
really has a lengthy history.
So what is new about
LASIK?
First, the microkeratome - an instrument
which cuts the corneal flap to the thickness of about one human hair,
predictably. It is usually motor driven with the depth set so the surgeon
does not have the arduous and almost impossible task of performing the
cut by hand.
Second, the reshaping is performed by
a computer driven laser - this results in minimal damage to the cornea
with extreme accuracy. Both were not possible with earlier keratomileusis.
What's the worst
thing that can happen to an eye during LASIK?
As with any surgery, complications are possible, and infection would
be the worst possible complication. Fortunately it is extremely rare
as modern sterile technique and antibiotics guard against this problem.
An infection, if caught early can often be cured with minimal damage.
Therefore it is imperative that each patient have a good relationship
with his or her surgeon, and understand clearly the doctor's on call
philosophy.
What is LASIK?
It is laser assisted in situ keratomileusis.
There are three steps. A keratome, acting like a lathe lifts a cap of
cornea much like opening the front cover of a hardbound book. The cap
looks like a perfect contact lens and is attached at one point like
a hinged door. Then the computer driven laser etches or removes a minute
amount of corneal tissue beneath the flap, the amount and shape determined
by the computer, which is programmed with the patient's visual error.
Finally the cap is replaced, again like closing the cover of the book.
What is no touch
laser?
It is PRK or photorefractive
keratectomy. This is an alternative to LASIK, an earlier surgery. Instead
of lifting the cap as in LASIK, the top layer of cells are removed either
with an instrument or with the laser, then the same tissue removal is
performed. However since the top layer of cells is removed it must regenerate
for the eye to heal.
What is the difference?
The overall results of one year is roughly the same. However LASIK recovery
as far as vision and discomfort is much faster, usually hours to one
day. PRK, since the cells must regrow over the central portion of the
cornea, is more painful for about 2 days and slower for vision return,
up to 10 days.
What are the risks
of PRK?
Infection and a hazy cornea after healing.
The latter is rare, about 1-2 percent but is particularly troublesome
as far as the visual result.
Risks of LASIK?
Infection, a wrinkled flap (requiring
repositioning), inflammation under the flap (requiring drops or sometimes
lifting and treating the flap).
Risks common to both LASIK and
PRK
Night glare - if the person's pupil dilates wider than the zone of
treatment, the person may notice glare around lights at night. This
is very bothersome but usually subsides with time. Night glare can
also result if there is left over correction which needs to be addressed
with glasses or a repeat treatment.
Loss of reading vision after the age of 40 - a nearsighted person,
by definition, sees up close. Treatment to restore distance vision
will remove the nearsightedness and therefore the ability to see up
close after the person is 40, this is very important to fully appreciate.
Less than perfect vision. All people want perfection, and it is possible,
but it is unwise to demand perfection of this surgery or your doctor.
Each person absorbs laser energy slightly differently and heals differently.
A very high percentage of patients see very well (20/40 or better
- legal driving vision) so this surgery represents a major lifestyle
change BUT if perfection is demanded surgery may not be a good choice.
What about touch-up
or enhancement surgery?
If the person sees less than the desired
result and there is a treatable correction left, the flap can be lifted
at a later date and more treatment administered. This possibility is
a comfort to those who preoperatively are perfectionists and to those
postoperatively who are not completely satisfied with their result.
Can 'no glasses no
contact lens' result be guaranteed?
No. Each patient must accept the slim
possibility of needing correction part time or all the time. AND, unless
one eye is left nearsighted purposely reading glasses will be necessary
for all people some time after the age 40.
Is this surgery helpful
for reading?
NO, it is a distance surgery only --- unless one eye is made nearsighted
on purpose which means that eye does not see far. This situation is
done with contact lenses so it is possible but a person should be very
sure he or she wants this type of result before surgery. Discuss this
with your surgeon carefully.
Should both eyes
be operated on at the same time?
You can but you must do what is comfortable for you and what is consistent
with what your surgeon believes. Bilateral simultaneous surgery is preferred
because of the convenience and rapid rehabilitation. Sequential e=surgery
is done for a greater margin of safety as far as risk of infection.
Statistics have shown that infection is extremely rare, but not impossible.
What are the alternatives?
Glasses, contact lenses, radial keratotomy
(deep vertical incisions made to reshape the cornea - an old effective
surgery still performed but largely replaced by lasers), intraocular
lens implants ( new technology not approved by the FDA but in use in
Europe and helpful for patients with vision errors beyond the reach
of the laser), intra-corneal implants called Intacs (FDA approved ring
implants placed in the layers of the cornea - a non-laser option which
does not remove tissue, does not directly affect the central cornea,
which is potentially reversible but works only for minor degrees of
nearsightedness. Thermal treatment of the cornea (non FDA approved reshaping
of the cornea by virtue of laser energy changing the shape with heat
changes.
Who can be treated
with LASIK?
Near and farsighted eyes as well as
astigmatism but not those eyes which need reading glasses. There are
limits to what the laser can do thus each person needs to consult a
physician.
How do I pick a surgeon?
Pick a doctor who has extensive micro
surgical experience, is board certified, is certified with the laser
and keratome he is using. Advertising is merely that and does not guarantee
any level of expertise. There are different approaches you will encounter
- choose what is comfortable for you. Some surgeons state they are LASIK
specialists only and do a volume oriented practice in which personal
contact with the surgeon is minimal and most evaluation is performed
by technicians or other doctors. Other surgeons are less geared towards
volume and work on a more personal basis, providing comprehensive care
for all eye problems while also performing LASIK. The MD's usually do
most if not all of your pre and post operative care as well as the surgery.
How long does the
LASIK take?
About 5-10 minutes per eye.
What is the recovery
like?
Your vision immediately after the surgery is blurry like looking under
water. Usually you are to go home and take a nap to let the flap stabilize
in position. The next morning your vision is usually quite good, and
should continue to clear. Pain is rare and mild and usually just the
first few hours after surgery.
Instructions after
surgery?
Usually wear a shield at night to prevent rubbing the eye for about
a week. Do not rub the eye for any reason for two weeks. Drops are used
for about two weeks. full Activity can be resumed almost immediately
as long as the flap is respected - avoid dirty areas, swimming, makeup
and again do not rub the eye!
When can any touch
up surgery be done?
Once the eye has stabilized and a reliable
residual error can be measured - usually 6 weeks to six months.
