Comparison of macular pigment optical density measured with dual wavelength autofluorescence between 6° and 9° plateau references in non-advanced age-related macular degeneration and control patients

Abstract

Purpose : Macular Pigment Optical Density (MPOD) can be measured with Heidelberg Spectralis dual wavelength autofluorescence by setting the plateau reference at different perifoveal eccentricities, where the MPOD value is arbitrarily defined as zero. Previous studies have used different plateau references, and there is a lack of evidence whether the choice of plateau location affects MPOD measurements across various macular disorders. We compared the MPOD values obtained with 2 commonly used plateau references of 6° and 9° in non-advanced Age-Related Macular Degeneration (AMD) and control patients.

Methods : Cross-sectional study where we prospectively enrolled 295 eyes of 166 individuals; 210 with non-advanced AMD (19 early AMD, 191 intermediate AMD) and 85 controls (>50 years) after institutional IRB approval. Participants were imaged and classified with color fundus photographs for AMD (Age-Related Eye Disease Study classification). Imaging was performed using Heidelberg Spectralis dual wavelength autofluorescence. MPOD sum of volume at 2° (SoV-2^o) values were calculated by setting plateau reference to 6° and 9°. A linear mixed-effects model was used to find association of the pairwise difference between SoV-2° values using 9° and 6° plateau references, with the various predictors of MPOD values, including age, presence of AMD, intra-ocular lens status, AREDS supplement use, and smoking history.

Results : On average, SoV-2^o was 13% higher when calculated using the 9^o reference plateau point (mean ± std. = 3227 ± 1172) instead of the 6^o reference (mean ± std. = 2853 ± 1034), with 374 ± 315 as the mean ± std. within-eye pairwise difference between the two plateau references. The SoV-2° calculated for 9^o and 6^o references were highly correlated (R = 0.96, p < 0.001). The pairwise difference between SoV-2° calculated with the 9^o and 6^o reference was not associated with age, presence of AMD, intra-ocular lens status, AREDS supplement use, or smoking history.

Conclusions : The MPOD sum of volume measurements calculated using the 9^o or 6^o references appear to be equivalent in non-advanced AMD and control patients. This work will enable direct comparison of the findings between studies using different plateau references.

This is a 2021 ARVO Annual Meeting abstract.