Laser in-situ keratomileuis (Lasik) is a laser refractive procedure in which a portion of the outermost layer of the eye is temporarily pulled away to allow a laser beam to make direct contact with the stroma of the cornea. The laser beam is used to reshape the cornea so that it focuses light properly into the eye. The outer layer of the eye is then replaced. Recovery time after a Lasik procedure is usually very short, often a matter of hours, and patient satisfaction with the procedure is very high. The procedure is nearly painless, and it can be used to treat myopia, hyperopia, and astigmatism. Lasik was introduced in the mid 1990’s, and is now the most commonly performed laser vision correction procedure.
PRK
Photorefractive keratectomy (PRK) was one of the first laser refractive surgery procedures performed to correct vision defects. In PRK, the outermost layer of the eye is removed, and then a laser beam is used to reshape the cornea. PRK can be used to correct myopia, hyperopia, and astigmatism, and results are fairly predictable. The removal of the outermost layer of the eye can result in significant discomfort, long recovery time, and the need for steroid drops to reduce inflammation in many patients. PRK was introduced in the early 1990’s.
RK
Radial keratotomy (RK) was introduced in the 1980’s as a surgical technique to correct myopia. RK involves surgical scarring of the peripheral cornea to change the curvature of the cornea. Small incisions are made at even intervals around the surface of the eye. As the incisions heal, scar tissue develops and causes the cornea to reflect light at different angles. RK outcomes are often unpredictable and rely heavily on the individual surgeon performing the procedure. It also introduces the possibility for serious eye damage and compromises the integrity of the eye. Since the introduction of the laser refractive procedures, RK has rarely been performed in the United States.
AK
Astigmatic keratotomy (AK) is a variation of RK that corrects astigmatism. In AK, incisions are made in the eye at angles instead of at even intervals. AK, like RK, is rarely performed in the United States due to the significant potential for complications and the introduction of laser refractive procedures.