These complications occur because the patient experiences an abnormal healing response, or because slightly too much or too little tissue is removed from the surface of the cornea. This occurs if light is entering from around the edge of the treatment area. Some people have pupils that dilate more than the treatment area. In other cases, the treatment area may be improperly centered. Re-treatment using a larger treatment zone will usually resolve this problem.
Complications affecting the health of the eye are extremely rare, but are possible.
During the early healing phase, the eye is susceptible to infection. You will be asked to follow certain instructions, including using antibiotic eye drops. Even if an infection does occur, use of antibiotic eye drops will almost always control the infection. Steroid eye drops are very important after excimer laser treatment, because they are used to control the healing response. However, if used improperly for too long, these drops can damage the eye by causing cataracts or glaucoma.