PHOTOASTIGMATIC REFRACTIVE KERATECTOMY FOR PRIMARY-TREATMENT AND REVISION OF MYOPIC ASTIGMATISM

Purpose: To evaluate the results in 43 eyes treated with a rotating ma sk for myopic astigmatism and followed for up to 1 year. Setting: Luce rne Eye Clinic, Cantonal Hospital, Lucerne, Switzerland. Methods: Thir ty-two patients (42 eyes) were selected to have photoastigmatic refrac tive keratectomy (PARK). In 33% (14 eyes), this treatment was the seco nd or third ablation. The Aesculap Meditec MEL 60 excimer laser was op erated in the scanning slit mode, and a rotating mask was used. To eva luate cylindrical shaping, vector analysis was performed. Results: One year after PARK, mean uncorrected visual acuity in all patients (26 e yes) improved from 20/160 preoperatively to 20/40. Surgically induced astigmatism in 20 of 26 eyes (77%) was within +/-1.00 diopter (D) of t he targeted induced astigmatism. At 1 year, 81% of patients who had pr imary excimer laser treatment for myopic astigmatism equivalent to -10 .00 D or less were within +/-1.00 D of target refraction compared with 44% of re-treated eyes. Conclusion: The result of PARK in eyes with l ow to moderate degrees of myopic astigmatism was satisfactory. However , in eyes with extensive scarring and wound healing activity after the first ablation, re-treatment was less predictable.