Laser Eye Surgery - Everything you need to know
What is Lasik 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.
There are three primary types of refractive errors: myopia,
hyperopia and astigmatism. Persons with myopia, or
nearsightedness, have more difficulty seeing distant objects as
clearly as near objects. Persons with hyperopia, or
farsightedness, have more difficulty seeing near objects as
clearly as distant objects. Astigmatism is a distortion of the
image on the retina caused by irregularities in the cornea or
lens of the eye. Combinations of myopia and astigmatism or
hyperopia and astigmatism are common. Glasses or contact lenses
are designed to compensate for the eye's imperfections. Surgical
procedures aimed at improving the focusing power of the eye are
called refractive surgery. In LASIK surgery, precise and
controlled removal of corneal tissue by a special laser reshapes
the cornea changing its focusing power. More about this and
everything else to do with Laser Eye Surgery can be found at
http://www.freewebs.com/lasik. This site contains all the info
you will ever need on the subject. Other types of refractive
surgery Radial Keratotomy or RK and Photorefractive Keratectomy
or PRK are other refractive surgeries used to reshape the
cornea. In RK, a very sharp knife is used 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. Often the exact same laser is used for the two
types of surgery. The major difference between the two surgeries
is the way that the stroma, the middle layer of the cornea, is
exposed before it is vaporized with the laser. In PRK, the top
layer of the cornea, called the epithelium, is scraped away to
expose the stromal layer underneath. In LASIK, a flap is cut in
the stromal layer and the flap is folded back. Another type of
refractive surgery is thermokeratoplasty in which heat is used
to reshape the cornea. The source of the heat can be a laser,
but it is a different kind of laser than is used for LASIK and
PRK. Other refractive devices include corneal ring segments that
are inserted into the stroma and special contact lenses that
temporarily reshape the cornea (orthokeratology). What the FDA
regulates In the United States, the Food and Drug Administration
(FDA) regulates the sale of medical devices such as the lasers
used for LASIK. Before a medical device can be legally sold in
the U.S., the person or company that wants to sell the device
must seek approval from the FDA. To gain approval, they must
present evidence that the device is reasonably safe and
effective for a particular use, the "indication." Once the FDA
has approved a medical device, a doctor may decide to use that
device for other indications if the doctor feels it is in the
best interest of a patient. The use of an approved device for
other than its FDA-approved indication is called "off-label
use." The FDA does not regulate off-label use or the practice of
medicine. The FDA does not have the authority to: Regulate a
doctor's practice. In other words, FDA does not tell doctors
what to do when running their business or what they can or
cannot tell their patients. Set the amount a doctor can charge
for LASIK eye surgery. "Insist" the patient information booklet
from the laser manufacturer be provided to the potential
patient. Make recommendations for individual doctors, clinics,
or eye centers. FDA does not maintain nor have access to any
such list of doctors performing LASIK eye surgery. Conduct or
provide a rating system on any medical device it regulates. The
first refractive laser systems approved by FDA were excimer
lasers for use in PRK to treat myopia and later to treat
astigmatism. However, doctors began using these lasers for LASIK
(not just PRK), and to treat other refractive errors (not just
myopia). Over the last several years, LASIK has become the main
surgery doctors use to treat myopia in the United States. More
recently, some laser manufacturers have gained FDA approval for
laser systems for LASIK to treat myopia, hyperopia and
astigmatism and for PRK to treat hyperopia and astigmatism. To
find out everything you need to know about Laser Eye Surgery
visit http://www.freewebs.com/lasik