Photoastigmatic Refractive Keratectomy or Laser in situ Keratomileusis for Moderate and High Myopic Astigmatism

Abstract

To compare the efficacy and safety of laser in situ keratomileusis (LASIK) and photoastigmatic refractive keratectomy (PARK) to treat moderate and higher myopic astigmatism. A retrospective nonrandomized study of 78 eyes with myopic astigmatism (range, 2.00 to 6.00 D) was undertaken. Thirty-eight eyes were treated with LASDK and 40 eyes were treated with PARK. Groups were similar in terms of baseline sphere and refraction. Photoablation for both LASDX and PARK was performed by single pass for correction of -6.00 D or less spherical equivalent refraction or multi-pass, multi-zone at 4, 5, and 6 mm for corrections greater than -6.00 D. Astigmatism was corrected using a single-pass ablation at 6.0 mm diameter. Visual acuity, manifest refraction, corneal topography, and patient satisfaction were measured preoperatively and postoperatively. Six months postoperatively, uncorrected visual acuity was 20/40 or better in 100% of LASEK eyes and 90.0% of PARK eyes; 20/25 in 86.84% LASEK eyes and 47.5% of PARK eyes; 20/20 in 65.75% of LASEK eyes and 15% of PARK eyes. Postoperative residual cylinder was -0.54 ± 0.32 D in LASEK eyes and -1.28 ± 0.80 D in PARK eyes. Postoperative residual cylinder axis remained stable (within 15° at 1 month postoperatively) in 61.1% of LASEK eyes and 40% of PARK eyes. In 5.3% of the LASEK eyes, corneal haze developed; 95.5% of PARK eyes developed corneal haze. One LASIK eye lost best spectacle-corrected visual acuity and 3 eyes (7.89%) had a cap complication. Three eyes (7.5%) lost 2 lines of spectacle-corrected visual acuity due to severe corneal haze. Among LASEK patients, 92.1% were highly satisfied and 62.5% of PARK patients were highly satisfied. For myopic astigmatism between 2.00 and 6.00 D, LASEK provided better accuracy, fewer complications, and higher patient satisfaction than PARK. PARK may achieve an incomplete cylindrical correction and may have a higher associated rist of loss of best spectacle-corrected visual acuity. [J Refract Surg 2000;16(suppl):S268-S271).