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LASIK Surgery
LASIK Information LASIK Surgery Laser Eye Surgery
2009
Eye Doctors Ophthalmologists Optometrists
Astigmatism Myopia Hyperopia Farsighted Farsightedness Nearsighted Nearsightedness Vision 20/20
Retina Cornea Lens
Refractive Surgery Radial Keratotomy Photorefractive Keratectomy
RK PRK
Informed Consent Bladeless LASIK Custom LASIK
20 / 20 Vision |
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What is meant by the term "LASIK surgery?"
LASIK is a surgical procedure intended to improve a person's vision and reduce their dependency on glasses / contact lenses. The acronym "LASIK" refers to the term laser assisted in situ keratomileusis or creating a flap in the cornea and then using a laser to reshape the underlying portion of the cornea.
How does LASIK sugery work? LASIK is a surgical improvement to correct the focusing
power of the eye performed by lifting the front surface of the eye, the corneal
epithelium. A mechanical microkeratome (a blade device) or a laser keratome (a
laser device) is used to cut a flap in the cornea. A hinge is left at one end of
this flap. The flap is folded back revealing the stroma, the middlesection of
the cornea. Pulses from a computer-controlled laser vaporize a portion of the
stroma and the flap is replaced.
Is the improvement permanent? LASIK is designed to be a permanent correction to the
vision. Studies to date show excellent vision stability for more than a decade
following treatment.
How do I know if I’m a
candidate to have LASIK? You’ll need to meet with a qualified LASIK surgeon for an
eye exam to know for sure if you are a good candidate for LASIK, but in general,
you should be eligible if you're over the age of 18 and have myopia
(nearsightedness), hyperopia (farsightedness) or astigmatism.
In addition, you must be in good general health with no health issues
that affect the eyes. You must not
have any active eye conditions that would affect healing.
Certain conditions, such as autoimmune diseases (e.g., lupus, rheumatoid
arthritis), immunodeficiency states (e.g., HIV) and diabetes, and some
medications (e.g., retinoic acid and steroids) may prevent proper healing after
a refractive procedure. You need to have had a stable vision prescription for at
least one year, and be free of any condition that could contribute to refractive
instability—if you have fluctuating hormones due to disease such as diabetes,
are pregnant or breastfeeding, or are taking medications that may cause
fluctuations in vision. LASIK surgeons cannot correct presbyopia, an age-related
vision problem, which occurs in most individuals starting in the early 40s and
progresses with age as muscles in the eye lose flexibility, making reading more
difficult. However, people who have presbyopia in combination with one of the
other conditions that is correctable by LASIK may still be candidates, although
the presbyopia would not be treated.
What are the benefits of
LASIK? With recent advances in technology, more and more people are
becoming candidates for LASIK, and it is now one of the most frequently
performed elective surgeries in the U.S.
Laser vision correction offers a permanent improvement for your vision,
and eliminates the ongoing expense and hassle of contact lenses and glasses,
without depriving the cornea of oxygen or irritating the eyes as contact lenses
can.
What are the possible
complications? As with any surgical procedure, there is always a risk of
complications from LASIK, but the risk of having a vision-reducing complication
is less than 1%. There have been no
reported cases of blindness resulting from laser eye treatment in the United
States, however the following risks exist:
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
nighttime 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).
What factors increase my risk
of developing a complication? The safety and effectiveness of refractive procedures 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 Are there 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
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 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. Is LASIK surgery FDA approved? Yes. After 10
years of trials, the FDA approved LASIK in 1998.
Since then, the technology has continued to evolve.
Is LASIK surgery painful? Most patients experience virtually no discomfort during the
LASIK procedure. Eye drop anesthesia is used to numb the eye prior to the
procedure, so no injections are necessary. Immediately after treatment, some
patients have reported minor discomfort, like having an eyelash or a dry contact
lens in their eye.
How long does the procedure
take? The LASIK procedure time is between five and fifteen
minutes. However, you should plan to
spend about 2 hours total for procedure preparation, additional paperwork, a
final examination, and to have ample opportunity to ask questions after the
procedure.
What is recovery like? Some patients have improved vision immediately after LASIK,
but it is important to take it easy for the first 24 hours following the
procedure. You should plan to
restrict activities to a minimum and keep eyes well lubricated with artificial
tears. It is not recommended to do any reading, computer work, or watch TV. Your vision may be hazy or blurry. This is typical as your
eyes continue to heal during LASIK recovery. Your eyes may burn, tear, itch, be
slightly red/swollen or feel like there is something, like an eyelash, in them.
You may experience sensitivity to light, glare, starbursts or halos around
lights. Any of these symptoms should improve considerably within the
first few days following treatment. The majority of patients are able to go to
work the next day, though vision continues to improve as the eyes heal and
adjust to their new shape. It will take up to 3-6 months for you vision to stabilize
and the healing process to be complete.
Vision may fluctuate from day to day as the eyes continue to heal, though
each person’s healing process will be different. What other types of eye surgeries are available?
Radial Keratotomy (RK) and Photorefractive Keratectomy (PRK) are two other eye
surgeries used to adjust the cornea.
With Radial Keratotomy a knife is used to cut small slits in the cornea to
change the shape. Photorefractive Keratectomy is a procedure that also uses a laser to reshape the cornea. This procedure was developed prior to LASIK surgery. LASIK and PRK both use the same type of laser. The primary difference between the two surgeries is the way surgeons expose the stroma before zapping it with the laser. In a PRK procedure, the epithelium, is scraped away to reveal the stroma. In a LASIK procedure, the surgeon cuts a flap in the stroma, the laser is used, then the flap is folded back into place. Additional glossary of eye and LASIK surgery related terms (all definitions courtesy FDA). Ablation zone
- The tissue that is removed during laser surgery. All-Laser LASIK - When a laser keratome
device is used to cut a corneal flap for LASIK surgery (sometimes referred to as
“bladeless LASIK”). Astigmatism
- A distortion of the image on the retina caused by irregularities in the cornea
or lens of the eye. Cornea
- The clear, front portion of the eye. The
cornea is the first part of the eye that refracts light and provides most of the
focusing power. Diopter
- The measurement of refractive error. A negative diopter value signifies
an eye with myopia (nearsightedness) and positive diopter value signifies an eye
with hyperopia (farsightedness). Dry Eye Syndrome
- A condition that occurs when the eyes do not produce enough tears to keep the
eye moist and comfortable. Ghost Image
- A fainter second image of the object someone is viewing. Halos
- The rings around lights due to optical imperfections in the eye. Haze
- Corneal clouding that causes the sensation of looking through a fog. Iris
- The colored ring of tissue suspended behind the cornea and immediately in
front of the lens. Keratectomy
- Surgical removal of corneal tissue. Keratotomy
- A surgical incision of the cornea. Keratitis
- inflammation of the cornea. Keratomileusis
– A carving of the cornea to reshape it. Laser
- An instrument that produces a powerful beam of light that can vaporize tissue. Laser Keratome - A laser device used to
create a flap in the cornea. Lens
- The part of the eye that provides focusing power. Microkeratome
- A surgical device that is affixed to the eye by use of a vacuum ring during
LASIK surgery. Once secured, a sharp
blade cuts a layer of the cornea to a predetermined depth. Myopia
- the inability to see distant objects as clearly as near objects. Nearsightedness
- the common term for myopia. Ophthalmologist
- A medical doctor that diagnoses and treats eye disorders and diseases. Optician
- An expert in making and fitting glasses and may also dispense contact lenses. Optometrist
- a primary eye care provider who diagnoses, manages, and treats disorders of
the visual system and eye diseases. Over-correction
- a complication of refractive surgery where the achieved amount of correction
is more than desired. PRK
- The acronym for photorefractive keratectomy which is a procedure involving the
removal of the surface layer of the cornea (epithelium) by scraping and use of
an excimer laser to reshape the part of the eye known as the stroma. Presbyopia
– An age related condition whereby reduced elasticity of the lens results in a
reduced ability of the eye to maintain clear focus as objects are moved closer.
Radial Keratotomy
- A surgical procedure designed to correct myopia (nearsightedness) by
flattening the cornea using radial (slit) cuts (often referred to as an “RK”). Retina
- A layer of tissue that lines the inside wall of the eye.
Sclera
- The tough, white, outer layer (coat) of the eyeball that, along with the
cornea, protects the eyeball. Stroma
- The middle, thickest layer of cornea tissue. Under-correction
- A complication of LASIK and other eye surgeries where the achieved amount of
vision correction is less than desired. Copyright 2010, 2009 |
