Influence of macular oedema on the measurement of macular pigment optical density

Introduction The purpose of this study was to determine macular pigment optical density (MPOD) in patients with macular degeneration as well as in patients with non-proliferative diabetic retinopathy. Methods Fifty-one phakic patients with either age-related macular degeneration (60 eyes of 30 patients; average age, 70.9 years) or non-proliferative diabetic retinopathy (42 eyes of 21 patients; average age, 61.7 years) were included in this cross-sectional study. Within the groups, patients were divided into those suffering from macular oedema and those with no oedema. An intra-subject comparison between eyes was carried out in both groups. Data were investigated on the basis of the coefficient of determination (R 2 ). Macular pigment optical density was measured by fundus reflectometry using the one-wavelength reflection method (Visucam 500; Carl Zeiss Meditec AG, Jena, Germany), in conformity with the method described by Schweitzer et al. (2010). We evaluated the maximum optical density in the measurement area (max OD) and the average optical density across the reference area in the measurement area (mean OD). Specifically, the influence of macular oedema on macular pigment optical density was examined. The subsequent measurement of retinal thickness was carried out by spectral-domain optical coherence tomography (Spectralis SD-OCT, Heidelberg Engineering GmbH, Heidelberg, Germany). Results The current study included two groups. The first group consisted of patients with non-proliferative diabetic retinopathy, as follows: no macular oedema on either side (max OD: R 2 = 43.2 %, p = 0.16; mean OD: R 2 = 68.7 %, p = 0.04); one-sided macular oedema (max OD: R 2 = 16 %, p = 0.60; mean OD: R 2 = 100 %, p = 0.04); or macular oedema in both eyes (max OD: R 2 = 79.7 %, p