Excimer Laser Photorefractive Keratectomy for Myopia: Results in 1165 Eyes

Abstract

BACKGROUND: We report the results of a prospective study conducted in Italy to evaluate the efficacy, safety, predictability, and complications of excimer laser photorefractive keratectomy for the correction of myopia. METHODS: Photorefractive keratectomy was performed on 1236 myopic sighted eyes in 16 centers, using the Summit Excimed 193 nm excimer laser. The attempted correction ranged from -0.80 to -25.00 diopters (mean, -7.83 ± 3.88 D). The population was divided into three groups of attempted correction: between -0.80 and -6.00 D, between -6.10 and -9.90 D, and between -10.00 and -25.00 D. We report the data of 1165 eyes at 1 month, 970 eyes at 3 months, 752 at 6 months, and 330 at 1 2 months. At each visit, we evaluated (1) the refractive changes over time; (2) the difference between attempted and achieved correction; (3) uncorrected and best spectacle corrected visual acuity; and (4) haze. RESULTS: Twelve months after surgery, the spherical equivalent refractive error in 146 eyes with attempted correction of -0.80 to -6.00 D was -0.52 ±1.04 D; 104 eyes (71.2%) were within ± 1.00 D of attempted correction. In 145 eyes with attempted correction of -6.10 to -9.90 D, the spherical equivalent refractive error was - 1 .66 ± 1.88 D; 50 eyes (34.5%) were within ± 1.00 D of attempted correction. The spherical equivalent refractive error in 39 eyes with attempted correction of - 1 0.00 to - 25.00 D was - 1 .86 ± 3.47 D; 1 1 eyes (28.2%) were within ±1.00 D of attempted correction. Eight eyes (2.4%) lost two or more Snellen lines of best spectacle corrected visual acuity. None of the treatments caused severe postoperative complications, or scarring. CONCLUSIONS: Photorefractive keratectomy proved safe and effective, but highly predictable only in the correction of myopia up to -6.00 D. Refract Corneal Surg 1 993;9:95- 1 04.) RÉSUMÉ INTRODUCTION: Nous présentons les résultats d'une étude prospective conduite en l'Italie afin d'évaluer l'efficacité, la sûreté, la prévisibilité, et les complications de la kératectomie photorefractive au laser excimer pour la myopie. MÉTHODES: 1236 yeux voyants ont subi la kératectomie photo- refractive dans 16 centres par le Summit ExciMed laser excimer à 193 nm. La correction souhaitée variait entre -0,8 et -25 dioptries (moyenne -7,83 ± 3,88 dioptries). La population fut divisée en trois groupes de correction souhaitée: entre -0,8 et -6,0 dioptries, entre -6,1 et -9,9 dioptries, et entre - 10,0 et -25,0 dioptries. Nous présentons les données de 1165 yeux suivis d'un mois, 970 yeux suivis de trois mois, 752 yeux suivis de six mois, et 330 yeux suivis de douze mois. À chaque visite nous évaluions (1) le changement réfractif avec le temps, (2) la différence entre la correction souhaitée et la correction réalisée, (3) l'acuité visuelle avec et sans correction, (4) la légère brume sous-épithéliale.