Loss of Muller's Cells and Photoreceptors in Macular Telangiectasia Type 2

Purpose: To correlate postmortem histology from a patient with macular telangiectasia (MacTel) type 2 with previously recorded clinical imaging data. Design: Observational clinicopathologic case report. Methods: The distribution of retinal blood vessels was used to map the location of serial wax sections in color fundus and optical coherence tomography (OCT) images. Fluorescent immunohistochemistry was used to visualize markers for Muller's cells (vimentin and retinaldehyde-binding protein 1), photoreceptors (L- M opsin, rhodopsin, and cytochrome oxidase 2), and the outer limiting membrane (OLM) (zonula occludens 1 and occludin). Main Outcome Measures: Distribution of specific markers in immunohistochemistry on retinal sections through the fovea in relation to clinical data. Results: The clinically recorded region of macular pigment loss in the macula correlated well with Miller's cell depletion. The OCT data showed a loss of the photoreceptor inner segment/outer segment (IS/OS) junction in the central retina, which correlated well with rod loss but not with cone loss. Markers for the OLM were lost where Muller's cells were lost. Conclusions: We have confirmed our previous finding of Muller's cell loss in MacTel type 2 and have shown that the area of Muller's cell loss matches the area of macular pigment depletion. In this patient, the IS/OS junction seen by OCT was absent in a region where rods were depleted but cones were still present.