Excimer laser phototherapeutic keratectomy for corneal diseases: a follow-up study

We performed phototherapeutic keratectomy (PTK) in 39 eyes of 38 patients with various corneal diseases. Patients were divided into four diagnostic entities: group 1 consistent of 11 eyes with postinfectious or posttraumatic corneal scars; 15 eyes with various corneal dystrophies or keratopathies comprised group 2; group 3 consisted to two eyes with recurrent corneal erosion; and 11 eyes with either primary or recurrent pterygia composed group 4. Postoperative follow-up ranged from 3 to 15 months (mean: 9 months). The goals of PTK (visual improvement, ocular comfort, or visibility for cataract extraction) were set individually for each patient and were achieved in 19 of 38 eyes (50%); one patient was lost to follow-up. Preoperatively, best corrected visual acuity improved two or more Snellen lines in nine of 31 eyes (29%). Both cases of recurrent corneal erosions were successfully treated. One eye lost two Snellen lines because of increased irregular astigmatism after PTK. In two eyes, corneal decompensation was observed 1 month after the operation, but no other serious complications were observed. The excimer laser was combined with surgical abrasions or use of topical EDTA, with good results. The excimer laser is a valuable tool for treating anterior corneal irregularities. It can also be combined with existing surgical methods. However, results can be improved with better patient selection criteria and by evaluating PTK on the basis of visual expectations and type and location of corneal pathology.