Preoperative examination excludes people with active ocular infection or inflammation. Candidates should not have a history of autoimmune or collagen vascular disease because of potential problems with wound healing. Latent herpes simplex virus may become reactivated after surgery, thus patients should be advised accordingly. 18 yr of age. People who tend to form keloids are discouraged from having refractive surgery because of the potential for increased scar tissue and haze formation in the cornea.
Patient motivation is essential, because although the risks of surgery are low, they do exist.
It is only when patients' expectations are met that they perceive a successful outcome of refractive surgery. The side effects of the refractive procedures discussed below include temporary foreign-body sensation, glare, and halos. Potential complications include over- and undercorrection, infection, irregular astigmatism, and, in excimer laser procedures, haze formation. If infection, irregular astigmatism, or haze formation causes permanent changes in the central cornea, a loss of best-corrected acuity could result. Although the complication rate is very low, the patient must be fully informed of all the potential risks and benefits of surgery so as to maintain realistic expectations.