The influence of ocular hypertension on retinal glial cells

AbstractWe describe the effects of unilateral laser‐induced ocular hypertension (OHT) in the macroglia and microglia of eyes with OHT and their contralateral normotensive untreated eyes. In both eyes, the glia was reactive even though, contrary to OHT‐eyes, no retinal ganglion cell loss or abnormalities in the electroretinogram were found in contralateral eyes. With respect GFAP immunostaining there were differences between contralateral and OHT‐eye. Signs of microglial activation in contralateral and in OHT‐eyes affected all retinal layers, including: morphological changes, migration, increased cell number, upregulation of activation markers and quantification of the area occupied by Iba‐1+ cells and of the arbor area of Iba‐1+ cells. In microglia, MHC‐II upregulation in contralateral eyes was similar to that in OHT‐eyes. By contrast, MHC‐II upregulation in macroglia was observed mainly in astrocytes in contralateral eyes and in Müller cells in OHT‐eyes. Only eyes with OHT had rod‐like microglia and rounded Iba‐1+ CD68+ CD86+ cells. Glial differences between contralateral and OHT‐eyes could help us to understand glaucoma pathophysiology and develop new strategies for treatment.