Evaluation of corneal functional optical zone after laser in situ keratomileusis

Abstract

Purpose: To evaluate the corneal functional optical zone (FOZ) after laser in situ keratomileusis (LASIK) using a primary 6.0 mm ablation diameter without a transition zone. Setting: University-based practice. Methods: In this retrospective study, 76 eyes of 53 patients who had LASIK for myopia were evaluated. The size of the preoperative and postoperative FOZ was compared in each eye. Preoperative refraction, attempted correction, and achieved correction were correlated with the preoperative and postoperative FOZ using regression analysis. Results: After LASIK, the FOZ decreased a mean 1.2 mm ± 0.67 (SD) (P < .0001). The size of the FOZ was correlated with the preoperative manifest refraction, attempted correction, and achieved correction (P < .0001). The FOZ reduction was significantly correlated with the preoperative manifest refraction, attempted correction, and achieved correction (P < .05). Before LASIK, there was no correlation between the FOZ and the preoperative manifest refraction (P =.9427). Conclusions: Spherical aberrations exist within the laser ablation zone and are related to the amount of myopic treatment. This has implications for patients with large pupil diameters under mesopic conditions. Future studies are necessary to understand the implications in patients with high refractive errors.