Corneal higher-order aberrations in early-onset cataract patients without identifiable risk factors: a retrospective...

This study aimed to evaluate anterior corneal higher-order aberrations (HOAs) and corneal curvature measurements in patients with idiopathic early-onset cataract (EOC) without identifiable risk factors and to compare these findings with those of patients with age-related cataract (ARC) and healthy controls.

This retrospective case-control study included 180 eyes from 90 subjects: 60 eyes from 30 EOC patients, 60 eyes from 30 ARC patients, and 60 eyes from 30 healthy controls. Subjects with systemic, genetic, or ocular disorders, previous ocular surgery, significant refractive error, regular medication use, smoking, regular alcohol consumption, or other factors that could affect corneal measurements were excluded. Anterior corneal aberrations and corneal curvature parameters were measured using a Scheimpflug-Placido topographer. Linear mixed models were used to account for inter-eye correlation, with group as a fixed factor and age as a continuous covariate. Pairwise post-hoc comparisons were performed only for outcomes with a significant overall group effect, and Holm-Bonferroni adjustment was applied.

After adjustment for age and inter-eye correlation, no significant group differences were observed in anterior segment biometric or corneal curvature parameters. Significant group effects were found for the root mean square of higher-order aberrations (RMS HOA), RMS coma, and RMS spherical aberration (RMS SA). RMS HOA and RMS coma were higher in EOC than in healthy controls (0.453 vs 0.287 μm and 0.352 vs 0.189 μm, respectively; adjusted p<0.001). RMS SA was higher in both EOC and ARC than in healthy controls (0.294 μm, 0.260 μm, and 0.092 μm, respectively; adjusted p<0.001). Across these outcomes, no statistically significant EOC-ARC contrasts were detected in the age-adjusted primary models. However, because the observed age ranges of the EOC and ARC groups did not overlap, these comparisons depended on extrapolation to a common age and do not establish equivalence. No significant group effect was found for RMS trefoil or RMS pentafoil.

Idiopathic EOC eyes showed higher age-adjusted anterior corneal aberrations, including RMS HOA, RMS coma, and RMS SA, than healthy controls. No statistically significant EOC-ARC contrasts were detected in the age-adjusted models; however, because the observed age ranges of the two groups did not overlap, these comparisons relied on extrapolation and should not be interpreted as evidence of equivalence. Corneal aberration assessment may provide additional information in EOC, although these exploratory findings require larger prospective studies before potential implications for cataract surgery planning and IOL selection can be clarified.