LASIK stands for Laser Assisted In Situ
Keratomileusis. In LASIK surgery, precise and controlled removal of corneal
tissue by a special laser reshapes the cornea changing its focusing power.
The eye and vision errors
The cornea is a part of the eye that helps focus light to create an image on
the retina. It works in much the same way that the lens of a camera focuses
light to create an image on film. The bending and focusing of light is also
known as refraction. Usually the shape of the cornea and the eye are not
perfect and the image on the retina is out-of-focus (blurred) or distorted.
These imperfections in the focusing power of the eye are called refractive
errors.
You are probably NOT a good candidate
for refractive surgery if:
You are not a risk taker
.
Certain complications are unavoidable in a percentage of patients, and
there are no long-term data available for current procedures.
It will jeopardize your career.
Some jobs prohibit certain
refractive procedures. Be sure to check with your employer/professional
society/military service before undergoing any procedure.
Cost is an issue.
Most medical insurance will not pay for
refractive surgery. Although the cost is coming down, it is still
significant.
You required a change in your contact
lens or glasses prescription in the past year.
This is called refractive instability.
Patients who are:
In their early 20s or younger,
Whose hormones are fluctuating due to
disease such as diabetes,
Who are pregnant or breastfeeding,
or
Who are taking medications such as
steroids that cause fluctuations in vision,
are more likely to have refractive
instability and probably should not have a refractive procedure.
You have a disease (e.g. lupus,
rheumatoid arthritis) or are on medications that may affect wound healing
.
Certain conditions, such as autoimmune diseases and immunodeficiency
states, and some medications, such as retinoic acid and steroids, may
prevent proper healing after a procedure.
You actively participate in contact
sports. You participate in boxing, wrestling, martial arts or other
activities in which blows to the face and eyes are a normal occurrence.
You are not an adult.
Currently, no lasers are approved for LASIK on persons under the age of
18.
Contraindications
The safety and effectiveness of refractive procedures has not been
determined in patients with some diseases. Do NOT have LASIK surgery 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) and blepharitis (inflammation of the eyelids
with crusting of the eyelashes).
Eye injuries or previous eye surgeries.
Keratoconus
Other Risk Factors
Your doctor should screen you for the following conditions or indicators of
risk:
Large pupils.
Make sure this evaluation is done in a
dark room. Younger patients and patients on certain medications may be
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 colored part of the eye. Most
refractive procedures change the eye’s focusing power by reshaping the
cornea (for example, by removing tissue). Performing a refractive
procedure on a cornea that is too thin or has too few cells lining the
back surface (endothelial cells) 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.
Most patients are very pleased with the
results of their refractive surgery. However, like any other medical
procedure, there are risks involved. That's why it is important for you to
understand the limitations and possible complications of refractive surgery.
Before undergoing a refractive procedure,
you should carefully weigh the risks and benefits based on your own personal
value system, and try to avoid being influenced by friends that have had the
procedure or doctors encouraging you to do so.
You may be undertreated or overtreated.
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. If you used
reading glasses before surgery, you will still need reading glasses after
surgery.
Results are generally not as good in
patients with very small or very large refractive errors.
Patients that require rather weak or
very strong glasses or contact lens prescriptions to see well before the
procedure are less likely to have 20/20 vision without glasses or contacts
after the procedure.
Results may not be lasting.
The level of improved vision you
experience after surgery may be temporary, especially if you are
farsighted or currently need reading glasses. It is especially important
for farsighted individuals to have a cycloplegic refraction (a vision exam
with lenses after dilating drops) as part of the screening process.
Patients whose manifest refraction (a vision exam with lenses before
dilating drops) is very different from their cycloplegic refraction are
more likely to have temporary results.
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. There is little known about how
refractive procedures affect other aspects of vision, such as contrast
sensitivity (the ability to see objects clearly against a similar
background or in dim lighting conditions). Some studies suggest that
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.
Therefore, patients with low contrast sensitivity to begin with probably
should not have a refractive procedure. It is important for you to know
that not all eye centers test contrast sensitivity, and that when it is
tested, it should be done in a dark room.
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. This
condition may be permanent. Intensive drop therapy and the use of plugs
or other procedures may be required.
Additional Risks if you are
Considering the Following:
Monovision
Monovision is one clinical technique used
to deal with the correction of presbyopia, the gradual loss of the ability
of the eye to change focus for close-up tasks that progresses with age. The
intent of monovision is for the presbyopic patient to use one eye for
distance viewing and one eye for near viewing. This practice was first
applied to fit contact lens wearers and more recently to LASIK and other
refractive surgeries. With contact lenses, a presbyopic patient has one eye
fit with a contact lens to correct distance vision, and the other eye fit
with a contact lens to correct near vision. In the same way, with LASIK, a
presbyopic patient has one eye operated on to correct the distance vision,
and the other operated on to correct the near vision. In other words, the
goal of the surgery is for one eye to have vision worse than 20/20,
the commonly referred to goal for LASIK surgical correction of distance
vision. Since one eye is corrected for distance viewing and the other eye is
corrected for near viewing, the two eyes no longer work together. This
results in poorer quality vision and a decrease in depth perception. These
effects of monovision are most noticeable in low lighting conditions and
when performing tasks requiring very sharp vision. Therefore, you may need
to wear glasses or contact lenses to fully correct both eyes for distance or
near when performing visually demanding tasks, such as driving at night,
operating dangerous equipment, or performing occupational tasks requiring
very sharp close vision (e.g., reading small print for long periods of
time).
Many patients cannot get used to having
one eye blurred at all times. The difference between monovision with contact
lenses and monovision with LASIK is that you can always take contact lenses
out or have them changed (the treatment is reversible and adjustable) as
opposed to LASIK, where the result of the surgery is not reversible
or adjustable. Therefore, if you are considering monovision with LASIK, make
sure you go through a trial period with contact lenses to see if you can
tolerate monovision, before having the irreversible surgery performed on
your eyes. Just before this trial period starts, find out if you pass your
state's driver's license requirements with monovision, or if you need
supplemental glasses to drive.
In addition, you should consider how much
your presbyopia is expected to increase in the future. Ask your doctor when
you should expect the results of your monovision surgery to no longer be
enough for you to see near-by objects clearly without the aid of glasses or
contacts, or when a second surgery might be required to further correct your
near vision.
Bilateral Simultaneous Treatment
You may choose to have LASIK surgery on
both eyes at the same time or to have surgery on one eye at a time. Although
the convenience of having surgery on both eyes on the same day is
attractive, this practice is riskier than having two separate surgeries. The
second eye may have a higher risk of developing an inflammation if surgery
is done on the same day than if surgery is performed on separate days. If a
malfunction of the laser or microkeratome occurs causing a complication with
the first eye, the second eye is more likely to also experience the same
complication if the surgery is performed on the same day rather than on
separate days.
If you decide to have one eye done at a
time, you and your doctor will decide how long to wait before having surgery
on the other eye. If both eyes are treated at the same time or before one
eye has a chance to fully heal, you and your doctor do not have the
advantage of being able to see how the first eye responds to surgery before
the second eye is treated.
Another disadvantage to having surgery on
both eyes at the same time is that the vision in both eyes may be blurred
after surgery until the initial healing process is over, rather than being
able to rely on clear vision in at least one eye at all times.
Even the best screened patients under the
care of most skilled surgeons can experience serious complications.
During surgery.
Malfunction of a device or other error,
such as cutting a flap of cornea through and through instead of making a
hinge during LASIK surgery, may lead to discontinuation of the procedure
or irreversible damage to the eye.
After surgery.
Some complications, such as migration
of the flap, inflammation or infection, may require another procedure
and/or intensive treatment with drops. Even with aggressive therapy, such
complications may lead to temporary loss of vision or even irreversible
blindness.
Under the care of an experienced doctor,
carefully screened candidates with reasonable expectations and a clear
understanding of the risks and alternatives are likely to be happy with the
results of their refractive procedure.
What to expect before, during, and after
surgery will vary from doctor to doctor and patient to patient. This
section is a compilation of patient information developed by manufacturers
and healthcare professionals, but cannot replace the dialogue you should
have with your doctor. Read this information carefully and with the
checklist,
discuss your expectations with your doctor.
Before Surgery
If you decide to go ahead with LASIK surgery, you will need an initial or
baseline evaluation by your eye doctor to determine if you are a good
candidate. This is what you need to know to prepare for the exam and what
you should expect:
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 up to several weeks after you have stopped using them
depending on the type of contact lenses you wear. Not leaving your contact
lenses out long enough for your cornea to assume its natural shape before
surgery can have negative consequences. These consequences include
inaccurate measurements and a poor surgical plan, resulting in poor vision
after surgery. These measurements, which determine how much corneal tissue
to remove, may need to be repeated at least a week after your initial
evaluation and before surgery to make sure they have not changed, especially
if you wear RGP or hard lenses. If you wear:
soft contact lenses, you should
stop wearing them for 2 weeks before your initial evaluation.
toric soft lenses or rigid gas
permeable (RGP) lenses, you should stop wearing them for at least 3
weeks before your initial evaluation.
hard lenses, you should stop
wearing them for at least 4 weeks before your initial evaluation.
You should tell your doctor:
about your past and present medical and
eye conditions
about all the medications you are
taking, including over-the-counter medications and any medications you may
be allergic to
Your doctor should perform a thorough
eye exam and discuss:
whether you are a good candidate
what the risks, benefits, and
alternatives of the surgery are
what you should expect before, during,
and after surgery
what your responsibilities will be
before, during, and after surgery
You should have the opportunity to ask
your doctor questions during this discussion. Give yourself plenty of time
to think about the risk/benefit discussion, to review any informational
literature provided by your doctor, and to have any additional questions
answered by your doctor before deciding to go through with surgery and
before signing the informed consent form.
You should not feel pressured by your
doctor, family, friends, or anyone else to make a decision about having
surgery. Carefully consider the pros and cons.
The day before surgery, you should
stop using:
creams
lotions
makeup
perfumes
These products as well as debris along
the eyelashes may increase the risk of infection during and after surgery.
Your doctor may ask you to scrub your eyelashes for a period of time before
surgery to get rid of residues and debris along the lashes.
Also before surgery, arrange for
transportation to and from your surgery and your first follow-up visit. On
the day of surgery, your doctor may give you some medicine to make you
relax. Because this medicine impairs your ability to drive and because your
vision may be blurry, even if you don't drive make sure someone can bring
you home after surgery.
During Surgery
The surgery should take less than 30 minutes. You will lie on your back in a
reclining chair in an exam room containing the laser system. The laser
system includes a large machine with a microscope attached to it and a
computer screen.
A numbing drop will be placed in your
eye, the area around your eye will be cleaned, and an instrument called a
lid speculum will be use to hold your eyelids open. A ring will be placed on
your eye and very high pressures will be applied to create suction to the
cornea. Your vision will dim while the suction ring is on and you may feel
the pressure and experience some discomfort during this part of the
procedure. The microkeratome, a cutting instrument, is attached to the
suction ring. Your doctor will use the blade of the microkeratome to cut a
flap in your cornea.
The microkeratome and the suction ring
are then removed. You will be able to see, but you will experience
fluctuating degrees of blurred vision during the rest of the procedure. The
doctor will then lift the flap and fold it back on its hinge, and dry the
exposed tissue.
The laser will be positioned over your
eye and you will be asked to stare at a light. This is not the laser
used to remove tissue from the cornea. This light is to help you keep your
eye fixed on one spot once the laser comes on. NOTE: If you cannot
stare at a fixed object for at least 60 seconds, you may not be a good
candidate for this surgery.
When your eye is in the correct position,
your doctor will start the laser. At this point in the surgery, you may
become aware of new sounds and smells. The pulse of the laser makes a
ticking sound. As the laser removes corneal tissue, some people have
reported a smell similar to burning hair. A computer controls the amount of
laser delivered to your eye. Before the start of surgery, your doctor will
have programmed the computer to vaporize a particular amount of tissue based
on the measurements taken at your initial evaluation. After the pulses of
laser energy vaporize the corneal tissue, the flap is put back into
position.
A shield should be placed over your eye
at the end of the procedure as protection, since no stitches are used to
hold the flap in place. It is important for you to wear this shield to
prevent you from rubbing your eye and putting pressure on your eye while you
sleep, and to protect your eye from accidentally being hit or poked until
the flap has healed.
Immediately after the procedure, 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. You should
plan on taking a few days off from work until these symptoms subside. You
should contact your doctor immediately and not wait for your scheduled
visit, if you experience severe pain, or if your vision or other symptoms
get worse instead of better.
You should see your doctor within the
first 24 to 48 hours after surgery and at regular intervals after that
for at least the first six months. At the first postoperative visit, your
doctor will remove the eye shield, test your vision, and examine your eye.
Your doctor may give you one or more types of eye drops to take at home to
help prevent infection and/or inflammation. You may also be advised to use
artificial tears to help lubricate the eye. Do not resume wearing a contact
lens in the operated eye, even if your vision is blurry.
You should wait one to three days
following surgery before beginning any non-contact sports, depending on the
amount of activity required, how you feel, and your doctor's instructions.
To help prevent infection, you may need
to wait for up to two weeks after surgery or until your doctor advises
you otherwise before using lotions, creams, or make-up around the eye.
Your doctor may advise you to continue scrubbing your eyelashes for a period
of time after surgery. You should also avoid swimming and using hot tubs or
whirlpools for 1-2 months.
Strenuous contact sports such as boxing,
football, karate, etc. should not be attempted for at least four weeks
after surgery. It is important to protect your eyes from anything that
might get in them and from being hit or bumped.
During the first few months after
surgery, your vision may fluctuate.
It may take up to three to six months
for your vision to stabilize after surgery.
Glare, haloes, difficulty driving at
night, and other visual symptoms may also persist during this
stabilization period. If further correction or enhancement is necessary,
you should wait until your eye measurements are consistent for two
consecutive visits at least 3 months apart before re-operation.
It is important to realize that
although distance vision may improve after re-operation, it is unlikely
that other visual symptoms such as glare or haloes will improve.
It is also important to note that no
laser company has presented enough evidence for the FDA to make
conclusions about the safety or effectiveness of enhancement surgery.
Contact your eye doctor immediately,
if you develop any new, unusual or worsening symptoms at any point after
surgery. Such symptoms could signal a problem that, if not treated early
enough, may lead to a loss of vision.
Career impact - does your job prohibit refractive surgery?
Cost - can you really afford this procedure?
Medical conditions - e.g., do you have an autoimmune disease or other major
illness? Do you have a chronic illness that might slow or alter healing?
Eye conditions - do you have or have you ever had any problems with your
eyes other than needing glasses or contacts?
Medications - do you take steroids or other drugs that might prevent
healing?
Stable refraction - has your prescription changed in the last year?
High or Low refractive error - do you use glasses/contacts only some of the
time? Do you need an unusually strong prescription?
Pupil size - are your pupils extra large in dim conditions?
Corneal thickness - do you
have thin corneas?
Know all the risks and procedure
limitations
Overtreatment or undertreatment - are you willing and able to have more than
one surgery to get the desired result?
May still need reading glasses - do you have presbyopia?
Results may not be lasting - do you think this is the last correction you
will ever need? Do you realize that long-term results are not known?
May permanently lose vision - do you know some patients may lose some vision
or experience blindness?
Development of visual symptoms - do you know about glare, halos, starbursts,
etc. and that night driving might be difficult?
Contrast sensitivity - do you know your vision could be significantly
reduced in dim light conditions?
Bilateral treatment - do you know the additional risks of having both eyes
treated at the same time?
Patient information - have
you read the patient information booklet about the laser being used for your
procedure?
Know preoperative, operative, and
postoperative expectations
No contact lenses prior to evaluation and surgery - can you go for an
extended period of time without wearing contact lenses?
Have a thorough exam - have you arranged not to drive or work after the
exam?
Read and understand the informed consent - has your doctor given you an
informed consent form to take home and answered all your questions?
No makeup before surgery - can you go 24-36 hours without makeup prior to
surgery?
Arrange for transportation - can someone drive you home after surgery?
Plan to take a few days to recover - can you take time off to take it easy
for a couple of days if necessary?
Expect not to see clearly for a few days - do you know you will not see
clearly immediately?
Know sights, smells, sounds of surgery - has your doctor made you feel
comfortable with the actual steps of the procedure?
Be prepared to take drops/medications- are you willing and able to put drops
in your eyes at regular intervals?
Be prepared to wear an eye shield - do you know you need to protect the eye
for a period of time after surgery to avoid injury?
Expect some pain/discomfort - do you know how much pain to expect?
Know when to seek help - do you understand what problems could occur and
when to seek medical intervention?
Know when to expect your vision to stop changing - are you aware that final
results could take up to months?
Make sure your refraction is stable before any further surgery - if you
don't get the desired result, do you know not to have an enhancement until
the prescription stops changing?
Please call your local eye care
professional for more information about laser refractive (PRK, LASIK)
surgery . To arrange for an appointment with the laser refractive surgeons (Dr.
Manolette Roque and Dr.
Johann Reyes) of the Ophthalmic Consultants Philippines Co., kindly
call:
Initial laser shots at the optical zone.
LASIK flap made.
Our
Eye Surgeons are