Comparison of Toric and Spherical Orthokeratology Lenses on High-Order Aberrations and Axial Length Elongation in Patients With Astigmatism.

Abstract

Purpose: To compare ocular high-order aberrations (HOAs) and axial length (AL) change between spherical and toric orthokeratology (ortho-k) lenses in the treatment of patients with moderate to high corneal astigmatism.

Methods: This was a prospective study involving 80 adolescents with myopia and moderate to high corneal astigmatism (≥1.50 diopters). These participants underwent consecutive ortho-k treatment at the Department of Ophthalmology of 363 Hospital between July 2021 and June 2023. The spherical group consisted of 41 subjects (41 eyes, 19 male and 22 female subjects; mean age: 11.15±2.09 years), who were fitted with traditional spherical ortho-k lenses. The toric group included 39 subjects (39 eyes, 15 male and 24 female subjects; mean age: 11.21±1.79 years), who were fitted with toric ortho-k lenses. All participants were followed up at 1 week, 1 month, and 3 months after wearing lenses. Uncorrected visual acuity (UCVA), lens decentration based on corneal topography, total ocular HOA, spherical aberrations (SA), coma aberrations (CA), and slitlamp microscopy were measured and compared between the two groups. Additionally, AL was assessed and compared between the groups after 12 months of lens wear.

Results: At 1 week, 1 month, and 3 months after wearing ortho-k lenses, the mean lens decentration in the toric group was (0.56±0.20) mm, (0.58±0.22) mm, and (0.56±0.24) mm, respectively, which were lower than those in the spherical group [(0.68±0.22) mm, (0.73±0.30) mm, and (0.72±0.27) mm, respectively], with statistically significant differences ( P <0.05). The CA values in the toric group were (0.27±0.17) μm, (0.30±0.24) μm, and (0.28±0.24) μm, which were lower than those in the spherical group [(0.39±0.24) μm, (0.44±0.33) μm, and (0.45±0.33) μm, respectively], with all differences being statistically significant ( P <0.05). No significant differences were observed between the two groups in terms of UCVA, total ocular HOA, SA, or corneal fluorescein staining ( P >0.05). Additionally, after 12 months of lens wear, no statistically significant difference in AL change between the two groups (spherical group: 0.25±0.18 mm; toric group: 0.24±0.12 mm; P >0.05).

Conclusion: For myopic adolescents with moderate to high corneal astigmatism (≥1.50 D), toric ortho-k lenses can reduce lens decentration compared with traditional spherical ortho-k lenses and induce less CA. However, toric and spherical ortho-k lenses demonstrate comparable outcomes in terms of UCVA, total ocular HOA, SA, safety profiles, and efficacy in myopia control.