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LASIK
is a surgical procedure intended to reduce a person's dependency on
glasses or contact lenses. All of the major three refractive
imperfections can be corrected: myopia (near-sightedness), hyperopia
(far-sightedness) and astigmatism (image distortion).
The surgery permanently changes the shape of the cornea,the clear covering of the front of the eye, using an excimer laser.
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A
microkeratome knife is used to cut a flap in the cornea. The flap is
folded back revealing the stroma (the middle section of the cornea).
Then, pulses from a computer-controlled laser vaporize a portion of the
stroma and the flap is replaced.
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What Other Forms of Surgery Are Available?
Radial
Keratotomy (RK) and Photorefractive Keratectomy (PRK) are other
refractive surgeries used to reshape the cornea. RK uses a very sharp
knife to cut slits in the cornea, changing its shape. PRK was the first
surgical procedure developed to reshape the cornea, by sculpting, using
a laser. Later, LASIK was developed. The same type of laser is used for
LASIK and PRK. LASIK remains the popular choice.
How is LASIK Eye Surgery Performed?
Eye
drops are the only anaesthesia. Sedation is not necessary, but you may
take an oral tranquilizer. Your eyelids and lashes are cleansed for
sterility and a sticky drape keeps your lashes out of the way. Your
lids are gently opened. You look at a blinking red light which keeps
your eye properly positioned. During the flap creation phase you have a
sensation of pressure and a greyness of vision. Then the laser is used
and you will hear a rapid clicking sound. The flap is replaced and it
takes about 3 minutes for it to stick down. After the procedure, you
will leave with an eye shield and eye drops to help your eye heal.
Also, your vision may be a little blurry for a few days. The procedure
takes under 10 minutes per eye.
How Accurate is the Excimer Laser?
Each
pulse of the 193nm laser will ablate or eliminate one three-thousandths
of one millimetre using cold energy. It is this level of unparalleled
accuracy which allows the programmed Excimer laser to precisely sculpt
the human cornea to reduce nearsightedness.
If I Require Surgery to Correct Defects, Can Both Eyes Be Treated at the Same Time?
It
is possible for most candidates to have surgery on both eyes on the
same day, conditional on the surgeon's approval and the patient's
careful informed consent. Even the safest surgery carries some small
statistical risks. Therefore, it is most conservative to separate
surgeries for the two eyes by some measure of time, depending on
patient need and situation.
What are the Risks and Benefits?
- Some patients lose vision.Some patients lose lines of vision on the vision chart that cannot be
corrected with glasses, contact lenses, or surgery as a result of
treatment.
- Some patients develop debilitating visual symptoms.Some patients develop glare, halos, and/or double vision that can
seriously affect night-time vision. Even with good vision on the vision
chart, some patients do not see as well in situations of low contrast,
such as at night or in fog, after treatment as compared to before
treatment.
- You may be under treated or over treated.Only a certain percent of patients achieve 20/20 vision without glasses
or contacts. You may require additional treatment, but additional
treatment may not be possible. You may still need glasses or contact
lenses after surgery. This may be true even if you only required a very
weak prescription before surgery. If you used reading glasses before
surgery, you may still need reading glasses after surgery.
- Some patients may develop severe dry eye syndrome.As a result of surgery, your eye may not be able to produce enough
tears to keep the eye moist and comfortable. Dry eye not only causes
discomfort, but can reduce visual quality due to intermittent blurring
and other visual symptoms. This condition may be permanent. Intensive
drop therapy and use of plugs or other procedures may be required.
- Results are generally not as good in patients with very large refractive errors of any type. You
should discuss your expectations with your doctor and realize that you
may still require glasses or contacts after the surgery.
- For some farsighted patients, results may diminish with age.If you are farsighted, the level of improved vision you experience
after surgery may decrease with age. This can occur if your manifest
refraction (a vision exam with lenses before dilating drops) is very
different from your cycloplegic refraction (a vision exam with lenses
after dilating drops).
- Long-term data are not available.LASIK is a relatively new technology. The first laser was approved for
LASIK eye surgery in 1998. Therefore, the long-term safety and
effectiveness of LASIK surgery is not known.
Am I a Candidate for LASIK Eye Surgery?
You are probably NOT a good candidate for refractive surgery if:
- It
will jeopardize your career. Some jobs prohibit certain refractive
procedures. Be sure to check with your employer, professional society,
military service (in the U.S. military, each school has its own rules)
before undergoing any procedure.
- You required a change in your contact lens or glasses prescription in the past year. This is called refractive instability.
- You
have a disease or are on medications that may affect wound healing .
Certain conditions, such as autoimmune diseases (e.g. lupus, rheumatoid
arthritis), immunodeficiency states (e.g. HIV), diabetes and some
medications (e.g. retinoic acid and steroids) may prevent proper
healing after a refractive procedure.
- You
actively participate in contact sports. You participate in combatant
sports (e.g. boxing, wrestling, martial arts). For combatant sports,
PRK is preferable, as there is no flap which can be dislodged in a
fight. This surgery is available with Mediseekers.
- You are not an adult. Currently, no lasers are approved for LASIK on persons under the age of 18.
Precautions:
The
safety and effectiveness of LASIK has not been determined in patients
with some diseases. Discuss with your doctor if you have a history of
any of the following:
- Herpes simplex or Herpes zoster (shingles) involving the eye area.
- Glaucoma, glaucoma suspect, or ocular hypertension.
- Eye diseases, such as uveitis/iritis (inflammations of the eye)
- Eye injuries or previous eye surgeries.
- Keratoconus
Other Risk Factors:
Your doctor should screen you for the following conditions or indicators of risk:
- Blepharitis.
Inflammation of the eyelids with crusting of the eyelashes, that may
increase the risk of infection or inflammation of the cornea after
LASIK.
- Large pupils. Make sure
this evaluation is done in a dark room. Although anyone may have large
pupils, younger patients and patients on certain medications may be
particularly prone to having large pupils under dim lighting
conditions. This can cause symptoms such as glare, halos, starbursts,
and ghost images (double vision) after surgery. In some patients these
symptoms may be debilitating. For example, a patient may no longer be
able to drive a car at night or in certain weather conditions, such as
fog.
- Thin Corneas. The cornea is
the thin clear covering of the eye that is over the iris, the coloured
part of the eye. Most refractive procedures change the eye’s focusing
power by reshaping the cornea by removing tissue. Performing a
refractive procedure on a cornea that is too thin may result in
blinding complications.
- Previous refractive surgery (e.g. RK, PRK, LASIK).Additional refractive surgery may not be recommended. The decision to
have additional refractive surgery must be made in consultation with
your doctor after careful consideration of your unique situation.
- Dry Eyes . LASIK surgery tends to aggravate this condition.
Will Medical Insurance Cover the Cost of Surgery?
Most medical insurance will NOT cover the cost of laser eye surgery.
What Do I Need to Do to Prepare for the Operation?
If
you wear contact lenses , it is a good idea to stop wearing them before
your baseline evaluation and switch to wearing your glasses full-time.
Contact lenses change the shape of your cornea for several weeks after
you have stopped using them. It’s best to stop wearing your contacts a
month before the operation to make sure the most accurate measurements
are taken. This will ensure the best surgical outcome.
The day before surgery, remember to stop using creams, lotions, make-up and perfumes.
Does LASIK Laser Surgery Hurt?
No.
The laser procedure itself is virtually painless. You will be aware of
a support which helps to hold your eye open. A slight pressure may be
felt during the procedure. You will be aware of the laser sounds while
you watch a red flashing light.
How Will I Feel Post-op?
Your
eye may burn, itch, or feel like there is something in it. You may
experience some discomfort, or in some cases, mild pain and your doctor
may suggest you take a mild pain reliever. Both your eyes may tear or
water. Your vision will probably be hazy or blurry. You will
instinctively want to rub your eye, but don't! Rubbing your eye could
dislodge the flap, requiring further treatment. In addition, you may
experience sensitivity to light, glare, starbursts or haloes around
lights, or the whites of your eye may look red or bloodshot. These
symptoms should improve considerably within the first few days after
surgery .
Can Anyone Guarantee 20/20 Vision?
No,
although 95% of patients with low through moderate ranges of
nearsightedness and/or astigmatism achieve normal or near normal
natural vision from just one surgery with LASIK. For those who do not
achieve this quality of vision from one surgery, enhancement surgery
can usually give the rest of the desired correction.
Is LASIK Surgery Tax Deductible?
In
the U.S. , laser surgery to fix your eyesight is a new deduction. Even
though the surgery is optional, it's now deemed a genuine medical
expense because it restores a function of the eye. When claiming, you
can include travel costs involved in getting medical care, including
hotel stays but not meals.
What are the Long Term Effects?
It
may take three to six months for your vision to stabilize after
surgery. Night vision and glare may persist for this period. After this
period, the laser correction will probably last for the rest of your
life. The cornea is a very stable tissue. |