Howerton
Eye Center - Austin Texas
Lasik - Laser Vision Correction
THE GOOD, THE BAD, AND THE VISUALLY
ACCEPTABLE
The benefits and risk of LASIK –
Laser Vision Correction
by Shawn Powell
- Austin, Texas
During consideration
of having LASIK – Laser Vision
Correction, each patient must
weigh the benefits and risks of having
such a procedure. It is essential
that patients understand potential
risks associated with the LASIK procedure.
Although, it has received FDA approval
and is considered to be safe, there
is risk of having a serious vision-threatening
complication. While approximately
1% of patients have complications
with their LASIK procedure, even fewer
experience a serious flap related
complication. LASIK is an extremely
effective procedure that is suitable
for high, moderate or low prescriptions.
Complications can
occur due to the Laser component of
the procedure or the Keratectomy step
of the procedure. There have been
no reported cases of blindness following
either PRK or LASIK, anywhere around
the world.
Undercorrection, is when the intended
amount of laser correction is not
obtained during the primary procedure.
In extreme cases of undercorrection,
after stabilization, an enhancement
may be necessary to obtain optimum
results. Undercorrection can result
from a number of factors: the healing
response of the eye, the hydration
of the cornea during treatment, the
laser’s calibration, or temperature
and humidity. Often time undercorrection
is deliberately induced to create
a monovision effect.
Overcorrection occurs
when the desired treatment is exceeded,
this causes an eye to become farsighted.
Often this condition will correct
itself, as the cornea tends to bounce
back somewhat towards its original
shape following the procedure. However,
should the patient remain hyperopic
(farsighted), it is possible to perform
an enhancement to obtain the desired
correction.
Corneal haze occurs
in the normal healing process of the
cornea; however for most patients
(95% +) it does not affect their vision.
The haze is actually caused by a collagen
protein that has developed on the
surface of the eye. For those patients
who do develop haze, it usually clears
gradually over many months following
the procedure.
People may experience
poor night vision, night glare, haloes
and starbursts even before having
vision correction by laser. Night
glare is common immediately following
the LASIK procedure and typically
last for a short period of time; however,
it is important that you discuss your
pupil size with your physician. Patients
with large pupils when dilated are
at a higher risk of having decreased
night vision.
Although the risk
of infection is rare, it is probably
the greatest risk during the first
48 to 72 hours following LASIK. Because
of the potential dangers resulting
from infection, antibiotic drops are
dispensed both before and after the
procedure.
Another complication
involves a non-infectious infiltrate
developing beneath the flap. A cloudy
accumulation of inflammatory cells
gives the appearance of swirling sand
and has been dubbed “Sands of
the Sahara”. The cause is unclear;
however, it can be successfully treated
by the use of topical steroid eye
drops or lifting the flap to remove
the debris.
Some patients find
their best vision after LASIK not
as good as with their glasses or contacts.
This is called a loss of best corrected
visual acuity. The final result depends
not only the procedure but how a patient
heals. Healing determines the speed
of visual recovery, the sharpness
of vision and the need for enhancement.
As the degree of correction increases,
the importance of healing to the final
visual outcome also increases.
Blindness is the
number one concern of all patients
considering LASIK. In surgery, as
in life, anything is possible; however,
there has not been a reported case
of permanent blindness occurring after
LASIK surgery.
A major component
of LASIK surgery is the creation of
the corneal flap (keratectomy). The
first complication associated with
the keratectomy is an incomplete flap,
which can be caused by an obstructed
microkeratome. Second is a thin flap,
which occurs if there is a loss of
suction. These types of complications
will not affect the final outcome;
however, it can prolong the recovery
process sometimes leading to a secondary
procedure to complete the correction.
Another complication
resulting from the keratectomy is
a “free cap”. A free cap
occurs when the flap is cut completely
across the cornea leaving no connecting
tissue. Although this is considered
a complication, LASIK was originally
performed without a hinge. This condition
is manageable by the surgeon, and
excellent vision can still be achieved.
LASIK dramatically
reduces your recovery time and decreases
the chance of many of the procedural
risks, as opposed to RK. The procedure
takes only a few minutes to complete
and entails minimal discomfort. LASIK
requires more technical skill and
training than other laser procedures.
The number of people
considering refractive surgery is
at an all time high and LASIK is considered
by virtually all refractive surgeons
to be the procedure of choice today.
Experience has shown
us that vision correction using the
excimer laser has been overwhelmingly
successful in reducing myopia, hyperopia
and astigmatism. While vision improves
following the procedure, the degree
of improvement may vary with each
individual. Overall, 98% of typical
patients achieve 20/40 vision or better
after one procedure allowing them
to drive legally, play sports, and
join the police or fire departments.
Patients may receive a second enhancement
procedure to further improve their
results if their vision is below legal
driving levels. Generally, there is
a 10% chance that a patient will require
an enhancement procedure. This chance
is less in patients with mild myopia
(approximately 5% chance) and greater
in patients with extreme myopia (approximately
20% chance).
What makes
LASIK an excellent vision correction
option for many people is the technology
provides an unparalleled degree of
precision and predictability.
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