Quantification of reduced macular pigment optical density in the central retina in macular telangiectasia type 2

Recently, a unique distribution, namely a reduction of macular pigment optical density (MPOD) within the central retina with a surrounding ring-like structure of preserved MPOD at about 6 degrees eccentricity was suggested to be a common finding in macular telangiectasia (MacTel) type 2. In order to quantify this reduced MPOD, 28 eyes of 14 patients with MacTel type 2 were investigated by fundus reflectometry and two wavelengths fundus autofluorescence (FAF; at 488 nm and 514 nm). Fundus reflectometry showed a reduced MPOD within the central 4 degrees eccentricity that was most absent temporal to the foveola. At 6 degrees, MP density was not different from normative values. Two wavelengths FAF was in accordance with these findings. Fundus reflectometry also allowed separate determination of lutein and zeaxanthin. The patients with MacTel type 2 showed a disproportionally high zeaxanthin reduction. The study suggests that in MacTel type 2, there might be an inability to accumulate MP in the central retina. This disease might serve as a model to further study abnormalities of MP distribution in retinal disorders and to elucidate the mechanisms of MP deposition in the retina.