One year clinical results of photoastigmatic refractive keratectomy for compound myopic astigmatism

Purpose: To evaluate the efficacy, predictability. and safety of excimer la ser photoastigmatic refractive keratectomy (PARK) to correct compound myopi c astigmatism. Setting: Departments of Ophthalmology, Robert Debre Hospital and Rothschild Foundation, Paris. France . Methods: This retrospective study included 27 eyes with compound myopic ast igmatism treated with a Nidek EC 5000 excimer laser. The refractive results were measured at 1 year, and the cylindrical component was analyzed by the Alpins method. Mean preoperative myopia was -4.50 diopters (D) (range -0.7 5 to -4.00 D) and mean preoperative cylinder, -1.64 D (range -0.75 to -4.00 D). Results: At 1 year, the spherical equivalent was -0.47 D (range +1.00 to -3 .00 D) and residual subjective astigmatism, -0.40 (range -0.25 to -1.50 D). Uncorrected visual acuity of 20/40 or better was obtained in 22 of the 27 eyes; 21 eyes were within +/-1.0 D of emmetropia. Vector analysis showed a mean coefficient adjustment of 1.50 D +/- 0.53 (SD), a mean axis shift of 2 .64 +/- 12.10 degrees, and a mean magnitude of error of 0.45 +/- 0.56 D. Ha ze was absent in 22 eyes and grade 1+ in 5 eyes. Five eyes gained 1 line of best corrected visual acuity and 3 lost 1 line. No patient lost more than 1 line. Conclusion: Excimer laser PARK successfully corrected low and moderate myop ia combined with up to 4.0 D of astigmatism with a low mean angle of error. To increase the accuracy of toric ablation, specific algorithms for the cy linder component are needed. J Cataract Refract Surg 1999; 25:911-920 (C) 1 999 ASCRS and ESCRS.