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Eye Surgery has become a
mainstream method of vision correction, and this
article will explain the advantages and
disadvantages of three different methods being
offered to the medical consumer.
Lasik Eye Surgery
LASIK is the acronym for Laser-Assisted In Situ
Keratomileusis and is an eye surgical system which
permanently corrects vision by removing a thin layer
of the cornea. This procedure works best on patients
with moderate to high degrees of myopia
(nearsightedness), low to moderate degrees of
hyperopia (farsightedness) and astigmatism
associated with myopia, and who have thick corneas.
It is the most well-known surgical vision correction
method.
People with normal eye sight see objects clearly
because images are brought into a correct focal
point by the cornea and lens of the eye. Ideally,
the cornea’s curvature is evenly matched to its
length in a normal eye. People with astigmatism,
myopia or hyperopia have irregularly shaped corneas,
so the objects seen are not focused properly. LASIK
changes corneal shape by precise removal of corneal
tissue, and by doing so corrects the eyes’ focusing
power.
There are, however, risks to LASIK eye surgery.
There is a remote chance of complete loss of vision.
If this happens, it is usually because the patient
had a pre-existing condition which should have
precluded the surgery in the first place, such as
pregnancy, cataracts, arthritis, diabetes, glaucoma,
or lupus. People with large pupils are also poor
candidates for LASIK. Dry eye syndrome will be
aggravated by this procedure.
A few patients complain that they permanently see
"ghost" images, have blurred vision, diminished
contrast and bad night vision. When LASIK was first
introduced, 5% of patients had post-operative
complaints; however, refinements in the procedure
have caused this rate to drop to less than 1% if
LASIK is performed by skilled practitioners and
patients are properly screened prior to surgery. If
problems do occur, they can often be resoved by a
retreatment.
FDA has approved LASIK laser eye surgery since 1998.
While there are a lot of satisfied patients, there
are however no long term studies about its effects.
Realize the limitations and the risks of LASIK eye
surgery before you sigh up for the procedure.
Intacs
Though less well known, these small implants can
improve vision in patients with mild to moderate
myopia without the risk of permanent eye damage
inherent in the tissue removal technique of LASIK.
Intacs are semi-circular disks implanted in the
cornea which stretch it to assume a flatter shape.
Though slightly less precise than LASIK, they are
removeable and replaceable, so if the patient has an
unexpected over- or under-correction, the implant
can be removed and another of a different size
inserted to obtain the desired correction. The
implants are located at the edge of the cornea, so
the central visual area is completely intact and
undamaged, and the strength of the cornea is
undiminished, making it a better option for pilots
and those who engage in contact sports where eye
injury is a possibility.
Intacs are unsuitable for severe myopia and more
than minor astigmatism (1.00 diopters), as the
cornea can only be stretched so far. If the Intacs
are removed, vision returns to its preoperative
level. Aside from vision correction, Intacs are also
used to treat keratoconus.
Intacs are FDA approved and 10 year studies have
revealed no major problems with Intacs and very few
patient complaints; however, because the procedure
takes more training than LASIK, there are fewer eye
surgery clinics offering it. However, the Intacs
website gives a list of practitioners in each state,
as well a few in Canada, Europe and Mexico.
Implants
Because many people do not want to risk LASIK and
Intacs cannot help those with severe vision
problems, intraocular lens implants (IOL) are a new
option approved by the FDA in 2004 to correct
moderate to severe nearsightedness. The Artisan
lens, manufactured by Ophtec, is similar to the type
of lens implant utilized to restore vision following
cataract eye surgery.
The new IOL, called the Artisan, is intended for
only patients who have 2.5 diopters or less of
astigmatism.
The artificial lens does not replace the natural
lens, but is inserted in front of it. The main
problem found with the implant was the steady loss
of endothelial cells in the corneas of patients who
received the implants. The endothelium is a layer of
cells that line the undersurface of the cornea and
are essential in keeping the cornea clear. A
three-year study showed a continual steady loss of
endothelial cells of 1.8 percent a year. At this
point, no one can predict whether this loss will
proceed at the same rate indefinitely, or even its
impact on corneal function.
To minimize long-term effects of the device on the
corneal endothelium, the FDA is requiring that the
new lenses be labelled to specify that they should
only be implanted in patients whose corneal
endothelial cells are thick enough to withstand
minor cell loss.
More serious complications were few: retinal
detachment (0.6%), cataract development (0.6%), and
corneal swelling (0.4%). The FDA is requiring Ophtec
to conduct a five-year follow-up survey of its
implant patients to better assess the post-surgical
incidence of cataract development, retinal
detachment and other ophthalmic diseases.
The Artisan lens is intended to be a permanent
implant.Though it can be removed surgically, vision
may not always return to what it was prior to
getting the lens. Because it does not affect
astigmatism, patients with this problem might still
require glasses.
About the Author:
Frank Hague's girlfriend has Intacs and is extremely
happy with them.
http://www.eye-surgery-now.info
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