The role of microglial activation in choroidal neovascular membranes of age-related macular degeneration patients

Objective To investigate the role of microglial activation in choroidal neovascular membranes(CNM) of age-related macular degeneration (AMD) patients. Methods Paraffin-embedded sections of CNM excised from 11 patients with wet AMD were collected. The microglial of sections were analyzed by immunohistochemistry with antibodies against HLA-DR antigen, CD 45 or CD 68. CNM were also dual labeled with CD 68 and vascular endothelium growth factor (VEGF). Results In inflammatory active CNM, abundant microglial cells were appeared characteristically amoeboid, with hypertrophic cell body and shorter process. In inflammatory inactive CNM, most of positive labeled microglial cells showed ramified, with small cell body and numerous nodular and slender processes. Double labeling study demonstrated that VEGF was mainly expressed in microglial cells. Conclusion Microglial are involved at different stages of the disease. Microglial activation is a prominent feature of the disease process. Key words: Neovascular, choroidal; Microglial; CD 68; CD 45; HLA-DR