eye disorders
Refractive Surgery
Introduction
Corneal refractive surgery alters the curvature of the cornea to focus light more precisely on the retina. (See Overview of Refractive Error .) The goal of refractive surgery is to decrease dependence on eyeglasses or contact lenses. Most people who undergo refractive surgery achieve this goal; over 95% do not need corrective lenses for distance vision. Ideal candidates for refractive surgery are healthy people aged 18 and older with healthy eyes who are not satisfied wearing eyeglasses or contact lenses. Contraindicationsto refractive surgery include Active ocular diseases, including severe dry eye Autoimmune or connective tissue diseases, which can impair wound healing Use ofisotretinoinoramiodarone Refraction should be stable for at least 1 year prior to surgery. Latent herpes simplex virus may be reactivated after surgery; patients should be advised accordingly. Adverse effectsof refractive surgery include temporary symptoms of Foreign body sensation Glare Halos Dryness Occasionally, these symptoms persist. Potential complicationsinclude Overcorrection Undercorrection Infection Irregular astigmatism In excimer laser procedures done on the superficial corneal stroma, haze formation is possible. If infection, irregular astigmatism, or haze formation causes permanent changes in the central cornea, best-corrected acuity could be decreased. The overall complication rate is low; chance of vision loss is<1% if the patient is considered a good candidate for refractive surgery preoperatively. 