Interocular Differences in Lens Morphology in Children With Unilateral Myopia

Abstract Purpose To investigate interocular differences in lens morphology in children with unilateral myopia, aiming to further explore the relationship between lens morphological changes and myopia development in the pediatric population. Methods This cross-sectional study enrolled children and adolescents with unilateral myopia. Unilateral myopia was defined as spherical equivalent (SE) ≤ − 0.75 D in one eye following cycloplegia, and SE between − 0.50 D and + 0.75 D in the fellow eye. Ocular biometric parameters, including axial length (AL) and lens thickness (LT), were measured using the IOLMaster 700. Lens parameters, including the anterior lens radius of curvature (ALR), posterior lens radius of curvature (PLR), and lens diameter (LD), were measured using the CASIA2 swept-source optical coherence tomography. Lens power (LP) was calculated using the Bennett formula. Paired t-tests were used to assess interocular differences in biometric parameters, and Linear regression analysis was performed to identify factors associated with refractive error. Results A total of 130 participants (age range 6–18 years; 49.23% female) were included. Compared with the emmetropic eyes, myopic eyes showed a smaller LT (P < 0.001) and larger ALR, PLR, and LD (all P < 0.05). Subgroup analyses revealed: In participants aged ≤ 11 years, myopic eyes exhibited larger ALR, PLR, and LD (all P < 0.05). In those aged > 11 years, myopic eyes exhibited larger ALR (P < 0.05), but no significant differences in PLR or LD. When anisometropia was ≤ 1.50 D, myopic eyes exhibited larger PLR (P < 0.05), but no significant differences in ALR or LD. When anisometropia was > 1.50 D, myopic eyes exhibited larger ALR and LD (all P < 0.05), but no significant difference in PLR. Conclusions In myopic eyes, lens power is reduced, and the lens morphology becomes flatter and thinner. PLR appear to serve as potential tipping points for these morphological changes.