Purpose
Macular pigment, composed of lutein, zeaxanthin, and meso-zeaxanthin, is postulated to protect against age-related macular degeneration (AMD), likely due to filtering blue light and its antioxidant properties. It was reported that the macular pigment optical density (MPOD) is associated with macular function evaluated by visual acuity and electroretinogram. However, the reproducibility of measurement of MPOD, which is essential for any application purpose, has not yet been determined. The main purpose is to determine the reproducibility of MPOD measurement by two-wave length autofluorescence method.
Methods
Fifty four eyes of 31 persons were enrolled in the study, including 6 normal eyes, 15 wet AMD, 9 dry AMD, 8 macular edema due to diabetic macular, branch retinal vein occlusion or macular telangiectasia and 16 tractional maculopathy including vitreomacular traction, epiretinal membrane and macular hole. MPOD was measured with a two-wave length (488 and 514nm) autofluorescence method with Spectralis HRA+OCT after pupil dilation. The measurement was repeated for each eye 10 minutes later. The Pearson Correlation analysis and Bland-Altman plot were used to assess the reproducibility between the two measurements.
Results
The mean sum of MPOD volume within eccentricities of 1°, 2° and 6° radius was 906.61±440.84, 2332.57±1142.44, 5872.32±3394.97 and 893.74±430.40, 2302.69±1131.46, 5832.13±3416.64 at first and second measurement respectively. The correlation coefficient of the association (r) between the two measurements was 0.994, 0.994 and 0.988 (all P<0.001) respectively, and the Bland-Altman plot showed 9.3%, 3.7% and 5.6% points outside the 95% limits of agreement, indicating an overall excellent reproducibility.The data for the reproducibility did not differ markedly among the various disease and normal eyes.
Conclusions
Under routine examination conditions with pupil dilation, MPOD measurement by two-wave length autofluorescence method showed a high reproducibility.