Retinal ganglion cell degeneration and dysfunction in glaucoma

Abstract

AbstractBoth dendritic shrinkage and dendritic outgrowth have been reported after chronic elevation of intraocular pressure and the longitudinal profile of retinal ganglion cell degeneration in glaucoma remains largely obscured. Monitoring dendritic and axonal degeneration requires long‐term, in vivo examination of axon and dendritic arborization. While clinical imaging only permits visualization of the ganglion cell layer and the nerve fiber layer, animal models have been established to track axonal and dendritic changes. Using a confocal scanning laser ophthalmoscope to image the retinae of transgenic mice (Thy‐1 YFP) that express fluorescent protein in neurons under the control of a Thy‐1 promoter, retinal ganglion cell degeneration has been shown to begin with progressive dendritic shrinkage, followed by loss of the axon and then the cell body after optic nerve crush. Although challenges remain to develop a glaucoma model with mildly to moderately elevated intraocular pressure lasting for a sufficiently long period of time with a clear optical media, it is promising that in vivo analysis of dendritic arborization would provide new insights into the neurobiology of retinal ganglion degeneration and neuroprotection in glaucoma.