Comparative Analysis of the Wave Front Aberrations and Ophthalmoergonomic Parameters after Excimer Laser and Orthokeratological Correction of Myopia in Patients over 35 Years

Abstract

Purpose. Comparative analysis of the wavefront aberrations and ophthalmoergonomic parameters after excimer laser and orthokeratological correction of myopia in patients aged over 35 years.Patients and methods. The study included 21 patients: 12 (24 eyes) after excimer laser correction of myopia (group 1) and 9 (18 eyes) after orthokeratology (group 2). The average age of patients after excimer laser surgery was 38.5 years, after orthokeratological correction 46.1 years. Special studies included ophthalmoergonomical tests: far and near distance visual acuity, capacity of the visual analyzer, visual productivity, reading velocity, mesopic vision, relative accommodation reserves, objective accommodative response, pseudo-accommodation volume. Wavefront aberrations were conducted on the OPD-scan 3.Results. The spherical equivalent of residual refraction was –0.625 ± 0.08D in the excimer group, and –1.58 ± 0.24D in orthokeratological group. Despite the difference in refraction, values of distance binocular and monocular visual acuity were the same in both groups: in group 1 monocular visual acuity was 0.74 ± 0.03, binocular 0.85 ± 0.03; in group 2 — 0.71 ± 0.06 and 0.89 ± 0.05 respectively. The parameters of both monocular and binocular accommodative response measured on Grand Seiko were 50 % higher in the excimer group compared to those in the orthokeratological group. Relative accommodation reserves appeared to be two times more in the excimer group. The volume of pseudo-accommodation was 2.375 ± 0.12D in group 1, which appeared to be 20 % more than in the group 2 (p = 0.0414). The level of wavefront aberrations was significantly higher in orthokeratological group with the exception of vertical aberrations and, especially horizontal coma, which were significantly higher after excimer laser surgery. Generally, the dynamics of aberrations in both groups correlates with changes of the corneal topography.Conclusion. Excimer laser surgery with hypocorrection is more recommended for patients aged 35–40, and orthokeratological correction for patients over 45 years old.