Laser eye surgery is a process by which the vision of an individual is corrected by means of a low-powered laser. It is an effective and popular practice and an alternative to either corrective eyeglasses or contacts.
History
Vision-repair surgery, also known as refractive eye surgery, is a relatively modern phenomenon that has emerged from years of experiments with the eye. The concept of correcting vision by reshaping the cornea is one that developed sometime in the mid 1800s. In the 1930s, Japanese doctor Tutomu Satu experimented on rabbits, and later on humans, by making incisions into the cornea. In Russia, Dr. Fyordorov adapted Dr. Satu's method and utilized radial keratotomy to correct vision. These early procedures of the 1980s were rather crude, but the procedures led to the first laser vision-correction procedure that removed tissue from the eye's surface and changed the curvature of the cornea.
Types of Laser Procedures
There are primarily two types of laser eye-surgery procedures: Photorefractive Keratectomy (PRK) and Laser-Assisted in situ Keratomileusis (LASIK). Although fundamentally similar, there are obvious distinctions between the two procedures. In PRK surgery, the top surface of the cornea, the epithelium, is removed so that the inner cornea can be exposed. The computer-assisted laser can then resculpt the curvature of the eye. The epithelium layer regenerates itself after the operation. In LASIK eye surgery, an incision is made either by a blade or a laser to create a small flap of the cornea. This flap is pulled back to allow the computer-assisted laser to resculpt the curvature of the eye. The flap is then returned to its original position.
The Laser
The laser used in the cases of both PRK and LASIK procedure is called an excimer laser. The excimer laser is an ultraviolet laser that is utilized in eye surgery because of its ability to add just enough energy to disrupt the bonds of biological matter. It does not cut or burn the matter as other lasers tend to do. The biological matter is removed by ablation, or evaporation, instead of by burning. The ability of the laser to remove very fine layers of material lends itself excellently to the delicate process of eye surgery.
Benefits
In both PRK and LASIK laser eye surgery, the procedures take less than 30 minutes to complete. They are done under local anesthesia. Recovery is generally painless and the results are close to immediate. LASIK offers a quicker recovery time because the flap of epithelium does not have to regenerate as is the case with PRK. The vision of the patient is very often corrected to 20/20 and that patient no longer requires the use of corrective lenses.
Warning
Although a majority of patients recover their full vision, there have been cases in which side effects have occurred. Patients recovering from both procedures have complained of cloudy vision, glare, double vision, halos and regression. There have also been reported cases of eye infection and severely dry eyes. LASIK eye surgery, specifically, can lead to complications with the creation of the flap of epithelium. The flap can be dislodged or completely removed.
Tags: biological matter, both LASIK, computer-assisted laser, excimer laser, flap epithelium, LASIK surgery, resculpt curvature