Reduced Macular Pigment Optical Volume Is Linked to High-Risk OCT Biomarkers and Lower Contrast Sensitivity Function in iAMD.

PURPOSE: To investigate relationships among macular pigment optical volume (MPOV), optical coherence tomography (OCT) biomarkers, and contrast sensitivity (CS) measured by the quantitative contrast sensitivity function (qCSF) test in intermediate age-related macular degeneration (iAMD).

METHODS

Sixty-five eyes from 34 patients with OCT-confirmed iAMD, visual acuity (VA) >20/100, and no confounding comorbidities underwent same-day qCSF testing (area under the logarithmic CS function [AULCSF], contrast acuity [CA], and CS at 1-18 cycles per degree [cpd]), MPOV imaging, and macular OCT. OCT features evaluated within the central 3-mm circle included outer nuclear layer (ONL) thickness, retinal pigment epithelium (RPE) volume, subretinal drusenoid deposits, hyporeflective drusen cores (hDCs), intraretinal hyperreflective foci, and incomplete RPE and outer retinal atrophy (iRORA). MPOV was quantified at 1°, 2°, and 9° eccentricities (plateau set at 9°). Generalized linear mixed-effects models assessed associations of MPOV with OCT biomarkers and qCSF metrics.

RESULTS

Lower MPOV values were associated with reduced ONL thickness (β*, 0.343-0.424; all P < 0.01), presence of hDCs (β*, -0.80 to -0.60; all P < 0.01), and iRORA at 1° (β*, -0.43; P = 0.03). MPOV at all eccentricities was associated with lower AULCSF (β*, 0.32-0.45), CA (β*, 0.38-0.48), and CS at 3 cpd and 6 cpd (β*, 0.39-0.69; all P < 0.05), but not with VA (β*, 0.10-0.28; all P > 0.05).

CONCLUSIONS

MPOV was significantly associated with high-risk OCT biomarkers and qCSF-derived CS metrics in iAMD, highlighting its potential role as a biomarker of structural integrity and functional impairment not captured by standard VA testing.