Higher order ocular aberrations and their relation to refractive error and ocular biometry in children.

Purpose: The interaction between higher order ocular aberrations (HOA) and refractive error is not yet fully understood. This study investigated HOA in relation to refractive error and ocular biometric parameters in a population with a high prevalence of ametropia. Methods: HOA were investigated in two cohorts of Caucasian children aged 9-10 and 15-16 years (n=313). HOA were measured for a 5mm pupil with the IRX3 aberrometer (Imagine Eyes, France). Cycloplegic refractive error and ocular biometry measures, including axial length and corneal curvature, were also assessed with the Shin-Nippon SRW-5000 auto-refractor and Zeiss IOLMaster respectively. Participants were divided into refractive groups for analysis of HOA. Results: The magnitude of total HOA was higher in this population at 0.27μm (Inter-quartile range (IQR) 0.22-0.32μm) than other HOA reported in the literature. The profile of HOA was not significantly different across the two age cohorts or across refractive groups; nor did spherical aberration differ significantly with age ( =0.07μm for both cohorts). Multivariate linear regression analysis demonstrated spherical aberration was significantly related to axial length (but not refractive grouping), with longer eyes having less positive values of fourth order and RMS spherical aberration. Conclusions: This study found no significant difference in HOA across refractive groups. The current study also highlights the importance of knowledge of axial length when analysing HOA.