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Laser Vision
Correction
Laser vision correction has come a long way
in a relatively short period of time.
History
In
1991, Ionas Pallikaris, MD, in Heraklion, Crete, was probably the
first to use a microkeratome to cut a thin flap of cornea and then
apply the excimer laser to remove tissue from within the cornea. He
coined the term laser in-situ keratomileusis (LASIK) for this procedure.
"Keratomileusis" is derived from two Greek word that literally mean
"to shape the cornea." "In-situ" means "in place." Therefore,
the term LASIK means "to reshape the cornea in place using laser."
Technique
The
LASIK procedure combines two sophisticated techniques of surgery to
correct refractive errors. The first technique involves the use of
an automated instrument, the microkeratome, to create a thin protective
layer of corneal tissue that covers the area to be sculpted by the
laser. This flap allows for rapid recovery of vision and reduces discomfort
after surgery. The second technique uses a computer-controlled
excimer laser -- a cold, invisible, ultraviolet laser -- to sculpt
the underlying cornea, correcting the refractive error. This is the
same laser that is used in PRK. The protective layer of tissue is
repositioned without sutures and is secure after a few minutes
so that a patch is not required. Visual recovery is typically rapid,
and there is little or no post-operative pain. Eye drops need only
to be taken for a week.
Our Results
20/40
is the vision required to pass the drivers test in the State of
California.
Recent FDA studies for the Customvue demonstrated 20/20 vision in 98% of patients
studied. A combination of the intralase and wavefront technology has the potential
for getting even better results.
Complications
In
experienced hands the complications of LASIK are extremely rare. Most
of the complications relate to the cutting of the flap and are
thus dependent on surgical skill. The worst possible complication
would be an infection with a permanent central opacity or a wrinkled
flap requiring a cornea transplant. Since Dr. Rabinowitz is an experienced
cornea transplant surgeon and often has to fix up other surgeons problems
he is ideally suited to deal with any serious complications relating
to the flap and since he routinely performs Cornea Transplants
on a weekly basis he would be best suited to deal with this problem
which to date has not occurred in any one of our LASIK patients. Other
complications beside the flap relate to the Laser itself.
Possible
Side Effects
Even
though the refractive error may be corrected and the visual acuity
may be good after LASIK, some patients experience one or more of the
following side effects of the procedure:
- Optical Aberrations: As with any refractive procedure, it is
common for patients to notice halos, ghost images, shadows,
and slight distortions for the first months after surgery. In
unusual circumstances, these optical aberrations may interfere
with normal visual activities.
- Night myopia: Because only the central portion of the
cornea is reshaped, eyes may become more nearsighted when the
pupil dilates and allows light to enter through the peripheral
cornea that had not been reshaped. Even if excellent unaided vision
is obtained during the daytime, a thin pair of glasses may be
required at night for optimum vision.
- Dry Eye: During the healing process, your eye
may feel dry, and you may need to use artificial tear replacement
for comfort temporarily.
- Discomfort: Most of the discomfort following LASIK
occurs within the first 24 hours and can easily be controlled
with Tylenol or similar mild pain relievers. The eyes may be transiently
more sensitive to sunlight following surgery.
Advantages
Consider
these important points when you are making your LASIK vision correction
decision.
- Rapid Recovery -- Most patients are back to work the
day after surgery. There is typically very little pain, and patients
recover vision within the first 24 hours, because the epithelium
is minimally disrupted. RK and PRK are more uncomfortable.
- Correction of a Full Range of myopia
-- Among the three procedures offered at Laser Eye Associates, Cedars-Sinai Medical
Center, Mark Goodson Building (RK, PRK and LASIK), LASIK is the only one that
can treat up to -15 diopters of myopia. RK and PRK can correct
only up to 5-7 DIOPTERS.
- Repeatability -- In the case of under-correction, LASIK
may be repeated by lifting the pre-made flap and adding additional
laser treatment. Once software is available for correcting astigmatism
and hyperopia, it will be possible to repeat the surgery
to treat these two disorders as well. Retreatment with PRK
requires several weeks of recovery time, several weeks or
months of treatment with steroid drops, and may induce corneal
scarring.
- Long-term Stability -- Because there is minimal disruption
of the normal corneal architecture and minimal wound healing,
it is likely that there will be minimal refractive change over
time. Although long-term data are not yet available, there
seems to be little or no change in the result between two weeks
and three months after surgery. There are no reports, thus far,
of myopic or hyperopic shift; however, many years of observation
will be required to know about the long-term stability of the
procedure.
- Structural Integrity
-- The flap is secure after the first day, and the eye is not
weakened as it is with RK.
- No Scarring -- There is little or no scarring in the
central cornea, as can occur with PRK.
- No Need for Long-term Post-operative Eye
Drops -- There is
no need to suppress wound healing with the use of steroids as
there is with PRK. LASIK patients can stop much more rapidly after
surgery.
Disadvantages
While
when weighed against the many advantages, the potential disadvantages
to LASIK vision correction are few, they should be considered nonetheless.
- Requires a Skillful Surgeon
-- Because of the complexity of the microkeratome, manual dexterity
and operative experience are required.
- Cost - LASIK is typically more expensive than
PRK.
Bladeless Intralase Technology
This very latest technology creates the flap
with a laser which offers several advantages over regular microkeratomes:
- reduced risk of vision threatening complications
- more accurate depths of flap (very important
in thin corneas)
- more accurate and reproducible results
- less need for enhancement
- true individualized customization of treatment
For more information on this technology click
here.
Frequently
Asked Questions (FAQs)
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