Treatment of simple hyperopia: comparison of laser in situ keratomileusis and laser thermal keratoplasty

Abstract

Purpose To evaluate and compare the efficacy, stability, and safety of laser in situ keratomileusis (LASIK) and laser thermal keratoplasty (LTK) for the treatment of simple hyperopia. Setting John Hill Eye and Laser Centre, Cape Town, South Africa. Methods This retrospective study comprised consecutive patients having primary treatment of simple hyperopia of up to 3.0 diopters (D) with astigmatism of 0.5 D or less. Treatment methods were as follows: Group 1 (81 eyes), LASIK with the Nidek EC-5000 excimer laser; Group 2 (69 eyes), LASIK with the LaserSight LSX® excimer laser; and Group 3 (84 eyes), LTK with the Sunrise holmium:YAG laser. Results The hyperopia decreased in all 3 groups. Both LASIK groups were stable by 1 month; there was continued regression in the LTK group for up to 18 months. The percentage of eyes achieving uncorrected visual acuities of 20/20 and 20/40 at 3 months were Nidek, 41% and 92%, respectively; LaserSight, 50% and 90%, respectively; and LTK, 21% and 89%, respectively. No eye lost more than 2 lines of best spectacle-corrected visual acuity. Surgically induced astigmatism (SIA) was evident in all 3 groups; it was highest in the LTK group. The mean posttreatment astigmatism was –0.47 D ± 0.40 (SD) (range 0 to −1.50 D) in the Nidek group, –0.45 ± 0.40 D (range 0 to −1.25 D) in the LaserSight group, and –0.81 ± 0.51 D (range 0 to −2.25 D) in the LTK group. The enhancement rates were 16.75%, 22.57%, and 38.30%, respectively. Because of the SIA, 61% of the LTK enhancements were corrected with LASIK. Conclusions All 3 treatment methods corrected hyperopia, but stability was achieved early in both LASIK groups, allowing early enhancement when necessary. Because LTK cannot currently correct astigmatism, many of the LTK repeat treatments required LASIK procedures. For these reasons, LASIK remains my preferred method to treat simple hyperopia up to +3.0 D.