An immunohistochemical study of neuronal and glial cell reactions in retinae of rats with experimental glaucoma

Glaucoma is a common disease seen in the eye clinic, but its associated pat hological processes, especially the role of glial cells in glaucomatous ret inae, are still under debate. The aim of the present work was to study the responses of astrocytes, Muller cells and microglia in retinae of rats with experimental glaucoma. Glaucoma was induced in adult male Wistar rats by c auterizing limbal-derived veins and the changes in glial fibrillary acidic protein (GFAP), OX42, OX18, OX6 and EDI expression were studied by immunohi stochemical staining. Neuronal cell viability was studied by immunostaining with the neuronal nuclei (NeuN) antibody. In the experimental glaucomatous eyes, a significant drop in the number of NeuN-positive neurons was observ ed from 7 days postoperation and beyond in both the ganglion cell layer and inner nuclear layer. The expression of GFAP and OX42 was increased during the first 2 months after operation and reduced in rats at 3 and 4 months. O X6 and OX18 immunoreactivity was induced in some microglia of both glaucoma tous and sham-operated control eyes. Possible mechanisms of the reaction of astrocytes, Muller cells and microglia in neuronal degeneration following glaucoma are discussed.