Macroglial changes in ipsilateral and contralateral rat retina in experimental glaucoma

Abstract

Abstract Purpose To investigate the effects of laser photocoagulation‐induced moderate ocular hypertension (OHT), on the macroglia of the ipsi‐and contralateral adult rat retinas at 3 weeks Methods OHT in the left eye was chronically induced by diode laser photocoagulation of the trabecular meshwork and the perilimbal and episcleral veins. Animals were divided in three group of study: Control (G0), age‐matched untreated animals. Group 1(G1), laser treated eyes which were further subdivided into two subgroups depending on the differences of averaged IOP with respect IOP levels of the contralateral eye, as follows: IOP difference lesser than 4 mmHg (G1A) and IOP difference greater than 4 mmHg (G1B). Retinal wholemounts were immunostained for GFAP. The retinal area occupied by astrocytes was determined and analyzed statistically. Results In comparison with the eyes of age‐matched untreated animals, the area of the retina occupied by astrocytes in the contrateral (untreated) eye was significantly reduced independently of the IOP level reached by the ipsilateral treated eye. The analysis of the area occupied by astrocytes in eyes with OHT revealed that there was a reduction of astrocytes significantly greater in G1B than in G1A with respect the contralateral eyes. Müller glial cells were undetected for GFAP staining in eyes of age‐matched untreated animals. However, in both treated and contralateral eyes Müller glial cells exhibited GFAP+immunoreactivity Conclusion At three weeks of moderate OHT, the Müller cells of the adult retina exhibited a GFAP+immunoreactivity and a reduction of the retinal area occupied by astrocytes both in the treated and contralateral eye