Macular pigment (MP), composed of hydroxycarotenoids (lutein, zeaxanthin, and meso-zeaxanthin), has been shown to enhance visual function in humans and is postulated to protect against age-related macular degeneration.
1,2 Previous studies have suggested that the spatial distribution of MP correlates with structural characteristics of the fovea, including the steepness, width, and depth of the foveal pit.
3 The optical density of macular pigment, known as macular pigment optical density (MPOD), peaks at the center of the foveola and characteristically decreases until it starts to plateau at approximately 6° to 8° eccentricity. Previous studies on normal eyes showed that MPOD measurement by dual-wavelength autofluorescence (AF) has an overall good intra-session and inter-session repeatability.
4,5 Previous studies have also shown good agreement between dual-wavelength autofluorescence technique and psychophysical techniques such as heterochromatic flicker photometry and motion photometry.
5–8 Several studies have confirmed a bimodal spatial distribution of MP that is characterized by a central peak of highest MP density surrounded by a ring with high-density values at approximately 0.7° from the fovea.
9–11 However, most of these values are represented as rings of various diameters centered on the fovea. To correlate MPOD with macular structural characteristics, it may be necessary to estimate the values along 30° radial sectors centered at the fovea and with the classical Early Treatment Diabetic Retinopathy Study (ETDRS) grid, which is used in describing optical coherence tomography (OCT)-related parameters in diabetic retinopathy.
12 This approach is more robust in the case of radial asymmetry of MP and could help to determine spatial correlations among color fundus photographs, OCT thickness values, and MPOD in health and in disease. The aim of the present study was to estimate MPOD values across different age groups in an Indian population across various spatial profiles using dual-wavelength autofluorescence.