Stereoacuity Following LASIK

Purpose: To evaluate the effect of laser in situ keratomileusis (LASIK) on stereoacuity(SA).Methods: This prospective study includes 200 patients scheduled for LASIK. SA was evaluated preoperatively and one week, one month and three months postoperativelyusing the Random Dot test. Patients with preoperative SA worse than 480 sec/arc wereexcluded from the study.Results: The study included 138 female (69%) and 62 male (31%) subjects. Sphericalequivalent was -0.5 to -12.0 D. Mean preoperative SA was 124.80±124.64 (range 480-15)sec/arc which deteriorated to 138.30±126.48 sec/arc one week after surgery (P=0.158)but improved to 111.30±112.15 sec/arc (P=0.002) one month and 103.65+112.20 sec/arc(P=0.001) three months postoperatively. Overall, stereoacuity decreased in 9.5%, increasedin 32.5% and remained unchanged in 58% of patients (P=0.007). Patients withanisometropia had worse SA; eventually, SA increased in 5 non-amblyopic anisometropicpatients.Conclusion: Despite the overall improvement in mean SA after LASIK, a minority ofpatients experienced decreased SA. Anisometropic patients without amblyopia seem to have a chance for improved SA after LASIK.