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.