Abstract
Macular pigment optical density (MPOD) models enhance understanding of macular xanthophyll distribution, particularly relevant to age-related macular degeneration. This study investigates an existing model and introduces a novel, more accurate and biologically relevant approach. MPOD spatial profiles of 48 eyes were obtained using dual-wavelength autofluorescence imaging, with structural data from OCT and OCT-angiography. MPOD data were analyzed using (a) an existing sum of exponential and Gaussian model (M(EG)) and (b) a novel sum of three Gaussians model (M(3G)). Extracted parameters generated individualized MPOD models, from which gradients and volumes were derived. M(3G)-derived variables were analyzed against OCT/OCTA data using factor analysis and multiple regression. M(3G) demonstrated a superior fit to MPOD data (SSE = 2.60 × 10(- 3)) compared to M(EG), (SSE = 35.7 × 10(- 3)) enabling automated fitting consistent over small and large datasets. M(3G) provided meaningful variables, including MPOD gradients, volumes and critical point eccentricities. Correlations included those between dependent variables of critical point eccentricities and central macular pigment volume with foveal avascular zone and foveal pit radii.The excellent data fit of M(3G) enables automated extraction of physiologically relevant parameters. Its three-component configuration is consistent with the location of macular xanthophylls. M(3G) is similar to models of foveal structure, suggesting a fundamental relationship.