The relationship between corneal biomechanical parameters and treatment outcomes of orthokeratology lenses

Abstract

Abstract Background To evaluate changes in corneal biomechanical properties after long-term orthokeratology (OK) treatment and the factors affecting treatment outcomes. Methods Twenty-four myopic teenagers who wore OK lenses for more than 1 year were included. Twenty-three individuals of the same age and with the same spherical equivalent wearing single-vision spectacles (SVS) were enrolled as controls. After routine eye examinations, corneal biomechanical properties and axial length were measured. Parameters were compared between groups. Results Less axial elongation (AE) occurred in the OK group (P = 0.021). The OK group experienced a statistically significant decrease in the A1 deformation amplitude (P = 0.02), whole eye movement maximum (P = 0.026), and Ambrósio’s relational thickness to the horizontal profile (ARTh) (P < 0.001), and a statistically significant increase in the pachyslope (P < 0.001) and Corvis biomechanical index (P < 0.001). Smaller ARTh and a larger highest concavity deflection area resulted in a better refractive state. The inhibitory effect of AE was better for older patients with smaller ARTh. Conclusions Long-term OK treatment slowed myopia progression by reshaping the cornea. Smaller ARTh after OK lens wear indicated a better refractive state and slower AE and could predict OK lens treatment outcomes.

Keywords

• Ambrósio’s relational thickness to the horizontal profile
• Orthokeratology lenses
• Myopia progression
• Corneal biomechanical properties