Early Results of Photorefractive Keratectomy for Myopic Astigmatism

Abstract

The Technolas Keracor 116 excimer laser has been used to correct myopic astigmatism. The purpose of this study was to evaluate the early results in our patients. The Technolas Keracor 116 excimer utilizes a scanning beam to correct myopic astigmatism. Following the correction of the astigmatic error, spherical myopic component is then treated. Twenty-eight eyes with myopic astigmatism were treated utilizing a 4 x 12 mm ablation zone for astigmatism and 4.5 mm to 6.6 mm transition zone for the spherical component at the same session. The mean preoperative spherical equivalent refraction was -4.87 +/- 3.48 diopters (D) (range: -1.00 to -14.25) and the mean preoperative astigmatic error was -2.53 +/- 1.49 D (range: -1.00 to -6.00 D) All eyes received dexamethasone eye drops for 3 months. At 6 months, the mean spherical equivalent refraction was +0.23 D (range +1.38 to -1.50 D), the mean postoperative refractive cylinder was -0.16 +/- 0.99 D (range: +1.50 to -2.00 D) and 78% of the eyes had a refraction within +/- 1 D. Fifty-five percent achieved 20/40 or better uncorrected visual acuity. In three cases there was one line loss and in two cases there was two line loss in best corrected spectacle visual acuity. Early results from this study suggest that excimer laser photorefractive keratectomy effectively reduces myopic astigmatism. The treatment of astigmatism offers a new challenge for excimer laser corneal surgery. Lasers utilize different methods to control the beam that reshapes the cornea.