Excimer laser keratectomy for astigmatism occurring after penetrating keratoplasty

Purpose: To review the results of photorefractive keratectomy used to treat astigmatism occurring after penetrating keratoplasty. Methods: Seven patients who had undergone corneal transplantation previously and had significant postoperative astigmatism were included. All these patients were intolerant of spectacle and contact lens correction. Excimer laser keratectomy was performed to reduce the astigmatic error. Minimum follow-up of 12 months was necessary for study inclusion. Results: The average refractive cylinder decreased from 5.32 diopters (D) preoperatively to 2.79 D postoperatively. The refractive cylinder was reduced in six of the seven eyes attempted. The average preoperative keratometric cylinder decreased from 5.54 D (range, 1.50-10.00 D) to 4.00 D (range, 1.00-7.50 D) postoperatively. The best spectacle-corrected visual acuity was unchanged (within 1 line) in three eyes, improved in two, and decreased in two. The complications included a loss of at least two lines in spectacle-corrected visual acuity in two eyes and scarring in one. Conclusions: Excimer laser keratectomy can reduce the astigmatism after penetrating keratoplasty. The excellent results in some eyes offer promise for this technique in the future.