Relationship between macular pigment and visual acuity in eyes with early age-related macular degeneration

Abstract. Purpose: Today the extent to which MP impacts visual function in early AMD remains unclear. This study examines the relationship between macular pigment optical density (MPOD) and high-contrast visual acuity (HC-VA) and low-contrast visual acuity (LC-VA) in eyes with early age-related macular degeneration (AMD). Methods: Measurements were made in 22 subjects with early AMD and 27 healthy control subjects. Distance best-corrected VA was measured using HC (96%) and LC (10%) Bailey-Lovie logMAR letter charts under photopic luminance conditions. MPOD was determined at the fovea through apparent motion photometry using the cathode ray tube-based Metropsis psychophysical vision test (Cambridge Research Systems). Results: No significant differences in foveal MPOD were detected between the control eyes (0.30 +/- 0.24 log units) and eyes with early AMD (0.27 +/- 0.15 log units). Neither were differences detected between the two groups in mean HC- and LC-VA. Foveal MPOD showed significant correlation with both photopic HC-VA (r = -0.47, p = 0.0008) and LC-VA (r = -0.46, p = 0.0008) such that as MPOD increased, photopic HC-VA and LC-VA improved (lower logMAR values). Conclusions: Low MP levels were related to worse visual function in both healthy eyes and eyes with early AMD. Our findings provide direction for future studies designed to improve retinal function through the use of oral supplements known to increase MP levels, especially in eyes with AMD and a low MPOD.