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Laser
eye surgery
| Laser
eye surgery is a procedure that has been used to correct
vision over the past 15 years. Although it is a relatively
common operation there are still misconceptions about
who can be treated, the effectiveness of the procedure,
and risk of complications. Today, LASIK is the most
common form of laser eye surgery, with over 6.5 million
procedures successsfully performed. Optometrist.com.au
brings you a definitive guide to Laser eye surgery (LASIK).
By Anna Ocysek,
Optometrist |
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How
does Laser eye surgery (LASIK) work?
The
etire LASIK procedure takes about 20 minutes, and involves
two surgical steps. Firstly, a specially designed instrument
is used to create a shallow cut in the front surface of the
eye, creating a paper-thin flap which is folded back.
The
second step involves the use of a cool beam excimer laser
to reshape the cornea, by removing microscopic layers of tissue,
to the precise refractive level required.
After
the treatment is completed, the flap is carefully re-positioned
to cover the newly contoured corneal tissue. The cornea has
natural bonding qualities, and almost immediately the flap
adheres to the underlying tissue, eliminating the need for
sutures. The result is an almost immediate healing response,
with the patient's vision stabilising rapidly.
Who
can be treated by Laser Vision Correction?
Although
the majority of LASIK is performed on myopic (shortsighted)
eyes, people with hyperopia (longsightedness), astigmatism,
and presbyopia can be helped with Laser eye surgery.
To
be eligible for LASIK, a person will generally have to be:
-
at least 20 years of age
- have
had stable vision for the past 12 months
- not
be pregnant
- be
free of certain diseases of the cornea and retina
- be
in good general health
Does
it hurt?
No.
Anaesthetic eye drops are used so no pain is experienced.
A slight feeling of pressure may be felt during the procedure.
Occasionally
mild discomfort is experienced after the procedure for up
to 6 hours. Approximately 2% of patients experience more significant
discomfort, which can be relieved with mild pain killers.
How
quickly after LASIK will I be able to see?
Most
patients will see an improvement in their natural eyesight
immediately after surgery. By the next day, around 99% of
all patients see well enough, independent of glasses, to drive
a car. Sight then settles down during the next couple of weeks.
Will
my good vision after LASIK be permanent?
With
the new LASIK techniques, the results achieved are expected
to last a lifetime. Experts around the world, based on the
data of more than 11 years of LASIK experience believe that
there will be no long term problems of significance with LASIK
treatment.
It
is important to realise that other eye conditions, such as
presbyopia (the need for reading glasses), and cataract will
still develop regardless of the LASIK.
Is
LASIK safe?
LASIK
has a very low incidence of complication. The most common
of these are:
-
Undercorrection
or overcorrection: Undercorrection of your
prescription is more common than overcorrection.
Initial overcorrection is usually expected and decreases
as the cornea stabilises. Both under and overcorrection
can be rectified with an enhancement. An enhancement
involves having further laser applied to the cornea.
Incidence of significant undercorrection 1-3%. Incidence
of significant overcorrection 2-3%
-
Regression:
Regression refers to the tendency of the power of
your eye to move towards its original glasses prescription
following the LASIK procedure. If regression does
occur, an enhancement may be necessary. Usually,
with LASIK the regression experienced is minimal
and is allowed for when planning the procedure.
Mild glasses may be prescribed for activities such
as night driving if only mild regression has occurred,
but in most cases an enhancement is recommended.
Incidence of significant regression: 1 in 300.
-
Decrease
in best corrected visual acuity: A small
number of patients experience a slight loss of visual
sharpness following LASIK. Incidence for shortsightedness
1%. Incidence for longsightedness 2%
-
LASIK
flap complications:
Serious flap complications are rare. Incidence 1
in 800.
-
Glare:
Sensitivity to glare may increase. Night glare is
more common and may last up to 3 months. Incidence
of significant glare: 1 in 1000.
-
Dry
Eye: If there is a pre-existing dry eye
problem, LASIK surgery can exacerbate this for the
first three months after surgery. Some people need
to use lubricating eye drops for the first 3 - 6
months. Incidence 1%.
-
Post-operative
discomfort: Discomfort is rare but may
include mild irritation, sensitivity to glare, watering
and dry eyes. These symptoms are usually short term.
Incidence 1 in 50 for discomfort, 1 in 500 for pain.
-
Post-operative
corneal haze:
Healing haze is the term for the collagen protein
that develops on the surface of the eye following
LASIK. Almost everyone develops trace degrees of
haze, usually during the first few weeks, and it
rarely affects vision. incidence of serious haze:
less than 1 in 2000.
-
Infection:
Antibiotic eye drops are used during the
procedure and for the week following the procedure.
Infection is an important issue, and fortunately,
is rare. Incidence of infection 1 in 5000.
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This
article was authored by Anna Ocysek. Anna is an Optometrist,
whose professional role includes laser education programs
and lectures for Optometrists. Anna practices in Queensland,
Australia. |
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