Structural and functional analysis of the eye according to the accommodation-age relationship

This study investigates how accommodative demand affects ocular function by examining variations in the anterior chamber depth (ACD), as well as the retinal and anterior surface curvatures of the crystalline lens across different age groups. The study included 96 right eyes from healthy individuals aged 18 to 66 years. Accommodation was assessed using an aberrometer under demands up to 5 diopters (D). Images of the anterior segment and retina were recorded and analyzed with custom software to adjust these surfaces to conic curves, providing data on changes in ACD, anterior surface curvature of the crystalline lens, and retinal shape during accommodation. The average age of participants was 35.42 ± 13.55 years. Accommodation matched the demand at low levels (up to 1D) but under-accommodated at higher demands. No significant differences were found in the anterior surface curvature of the crystalline lens with increased accommodation, though a weak trend was observed in younger individuals. ACD significantly decreased with accommodation due to the anterior displacement of the lens. Retinal curvature showed significant changes, including flattening, with increased accommodative demand. There were correlations between the anterior surface eccentricity of the crystalline lens and both ACD changes and retinal eccentricity. In conclusion, accommodation effectively responds to demands up to 1D across all ages. Our findings suggest a tendency for retinal curvature to flatten to higher demands, requiring further validation. While the central curvature of the anterior surface of the crystalline lens does not change significantly, ACD decreases with accommodation, indicating how age and presbyopia influence accommodative capacity and structural changes in the eye.