Crystalline lens geometry from a clinical OCT-based biometer in pre-cataract surgery patients

Understanding the interplay between crystalline geometry and refractive error is important to get insights into lens aging and guide the design and selection of artificial intraocular lenses that replace the aged crystalline lens in refractive lens exchange and cataract surgery. In this study we evaluated the relationships between the full geometry of the crystalline lens and age, axial length (AL), and refractive error in patients scheduled for cataract surgery. Optical Coherence Tomography (IOLMaster700, Zeiss) combined with custom-developed full crystalline lens shape reconstruction algorithms were applied to image 453 eyes from 327 subjects and quantify crystalline lens geometrical parameters, including thickness (LT), radius of the anterior and posterior surface (RAL, RPL), volume (LV), surface area (LSA), diameter (DIA) and equatorial plane position (EPP). Correlation and partial correlation analysis (controlling for age, AL, and refraction) were performed. Multiple linear regression models evaluated whether age and AL or refraction predicted LT, DIA, LV and LSA. Age was significantly correlated with LT, LV, LSA, DIA, EPP, and refraction, and these associations persisted after controlling for AL or manifest refraction spherical equivalent. AL was correlated with LT, EPP, DIA, RAL, and with DIA, RAL, RPL and LSA after adjusting for age. Overall, the lens expands axially and meridionally with age, increasing in thickness, diameter, volume and surface area, accompanied by a hyperopic shift. Longer eyes exhibited lenses with larger diameters and flatter anterior and posterior surfaces, partially offsetting myopia. These findings suggest that age- and growth-related lens remodeling contributes to refractive shifts.