Laser eye surgery is a vision correction option for many people with nearsightedness, farsightedness or astigmatism. These vision problems are called refractive errors. Laser vision-correction procedures reshape the cornea--the clear area at the front of the eye--to correct the misaligned focus that causes refractive errors. Different types of laser vision-correction surgery available in the United States include LASIK, PRK and LASEK.
LASIK
Laser-assisted in situ keratomileusis, or LASIK, is the most commonly performed laser vision-correction surgery in the United States. Approximately 700,000 LASIK procedures are performed annually, according to the American Academy of Ophthalmology and the International Society of Refractive Surgery.
The LASIK procedure begins with numbing the eye surface. After applying a cup over the eye to prevent movement, the eye doctor cuts and removes a small flap of corneal tissue from the front of the eye. A computer-guided laser then reshapes the exposed cornea. The corneal flap is replaced over the newly shaped tissue. The flap bonds within a few minutes, making stitches unnecessary.
The American Academy of Ophthalmology and the International Society of Refractive Surgery note that LASIK not an option for people with certain conditions, including advanced glaucoma, cataracts and certain diseases of the cornea. Additionally, LASIK may not may be appropriate for people with dry eye syndrome because the procedure may worsen the condition, reports the U.S. Food and Drug Administration.
PRK
Photorefractive keratectomy, or PRK, was the first laser vision-correction surgery approved by the FDA in 1995, reports the patient information site All About Vision. PRK differs from LASIK in that the laser correction occurs directly on the cornea surface without the creation of a flap. For this reason, PRK may be preferred over LASIK among people with thin corneas in whom creation of a flap may prove challenging, reports the Cleveland Clinic.
The thin outer layer of the cornea, the epithelium, is removed for a PRK procedure. Eye discomfort typically occurs for several days after the procedure until the corneal epithelium regrows. A bandage contact lens protects the eye surface during the corneal epithelium healing process.
LASEK
Laser-assisted subepithelial keratomileusis, or LASEK, is a modified version of PRK. Rather than removing the corneal epithelium, it is cut from the eye surface and replaced after laser reshaping of the cornea. As with PRK, a bandage contact lens protects the eye for several days after the LASEK procedure. Eye discomfort is common during this initial phase of the healing process. People undergoing a LASEK procedure have less risk of developing postoperative dry eye compared to those who undergo a LASIK procedure, reports the patient information website All About Vision.
References
- American Academy of Ophthalmology and the International Society of Refractive Surgery: Is LASIK for Me? A Patient's Guide to Refractive Surgery
- Eye Surgery Education Council: LASIK Fundamentals: Step By Step
- U.S. Food and Drug Administration: When is LASIK not for Me?
- All About Vision: Corrective Eye Surgery Basics
- Cleveland Clinic: Photorefractive Keratotomy (PRK) Eye Surgery
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