LASIK
Educational Material -
Laser Vision Surgery
Laser In-Situ Keratomileusis
Why is LASIK so popular?
LASIK is the most popular form of vision correction surgery in
the United States today. Every year, over 1 million people
receive this procedure. (Click on any topic or scroll down)
What is LASIK?
How does it work?
What does LASIK treat?
What are the results?
What is LASIK?
The word "LASIK" is an acronym (therefore spelled in capital letters)
for LASer In-situ Keratomileusis:
Laser:
intense, highly concentrated beam of light (an acronym for Light Amplification by Stimulated Emission
of Radiation; however, now such a common word that it is seldom seen
completely capitalized)
In-situ: Greek word meaning "in place"
Keratomileusis: combination of two Greek words:
kerato "the cornea"
mileusis "to shape"
Therefore, LASIK = "a light to shape the cornea in place"
LASIK is a quick and virtually painless procedure, resulting in the majority
of patients experiencing improved vision and a reduced dependency on corrective
eyewear.
Back to top
How does it work?
|
Specifically, LASIK involves the use of laser light from an excimer laser (a "cool" laser,
such as the VISX) to permanently change the shape of the cornea. 90% of the cornea
is called the stroma, with an overlying layer of cells called the epithelium.
A thin membrane separates the two and is called Bowman's membrane. |
|
|
A corneal flap is first made (using the Intralase femtosecond laser - another "cool" laser)
and then gently lifted. The corneal reshaping takes place in the deeper part
of the cornea below, called the stroma. Laser removal of stroma produces permanent
reshaping of the cornea, thereby affecting its refractive power. After the reshaping
step, the flap is then precisely replaced without the need for any sutures.
With the corneal curvature changed to provide better focus for the eye, the patient's
need for glasses or contact lenses (which used to provide this focus) is typically
greatly reduced.
Photo Refractive Keratectomy (PRK) is
a refractive procedure, popular prior to the appearance of LASIK, which utilizes
the same
excimer laser
to
reshape
the cornea without the construction
of a flap. This allows the laser to immediately start on the stroma. However,
PRK's "surface ablations" create
a temporary loss of epithelium, resulting in some patient discomfort with the
need
to
wear a "bandage" contact
lens for a few days. By comparison, LASIK patients typically experience very
little discomfort post-operatively and have no need for a bandage lens.
As LASIK is a surgical procedure conducted on a delicate part of the eye, it
is important that you are well educated on the benefits and LASIK Risks of the procedure,
understand the importance of thorough screening and comprehensive pre-operative
exam, and maintain realistic expectations.
Back to top
What does LASIK treat?
With a few exceptions, LASIK can treat the following conditions that require
the use of glasses and contact lenses for clear vision:
(Click on any topic for more information on a separate page.)
·
Myopia between -0.5 and -10 diopters
·
Hyperopia between +0.5 and +6.0 diopters
·
Astigmatism between 0.5 and 6.0 diopters
·
Presbyopia using Monovision
If, after your initial procedure, your vision without glasses is not satisfactory,
then a procedure called enhancement, glasses or contacts are options for additional
improvement in vision.
In some cases, patients who have had previous eye surgery may qualify for LASIK.
LASIK may be performed after previous Radial Keratotomy (RK), Photorefractive
Keratotomy (PRK), and cataract surgery. Dr. Seibel can discuss your options
at your initial consultation.
What are the results?
No one can guarantee exact results due to the unique healing factor of each patient
and potential variability of individual surgical techniques, eye measurements,
and equipment. An excellent surgeon can largely control the latter three variables.
United States statistics show that over 50% of patients achieve 20/20 vision
or better, although it is not essential to be 20/20 to be satisfied and functional.
The success rates can be as high as 98% with patients achieving 20/20 or better
without wearing glasses or contact lenses. For comparison, the requirement for
a driver's license in most states is 20/40, which is 3 lines larger print than
20/20.
Back to top
For more, see:
Common LASIK Questions
and Answers
.
|
LASIK Overview
