I/R injury induced progressive gliosis in the retina. Expression of retinal glial fibrillary acidic protein (GFAP) was monitored by immunohistochemistry at 5 time points (3, 7, 14, 21 and 28 days) after I/R injury. GFAP expression progressively increased through the retinal layers in I/R eyes compared to control eyes. Green fluorescence (Alexaflour 488) = GFAP. Nuclei were stained with DAPI (blue fluorescence).