Anatomical and functional damage in experimental glaucoma.

Glaucoma is a progressive neurodegenerative disease caused by retinal ganglion cell (RGC) loss. One important risk factor for glaucoma is elevated intraocular pressure and thus many animal models are based on spontaneous or induced ocular hypertension (OHT). Using these models it has been shown that RGCs initially suffer an impairment of the active axonal transport that progresses to a lack of passive diffusion along the axon. This axonal damage eventually causes the death of the parent RGCs in pie-shaped sectors of the retina, but there is also diffuse RGC loss, without involving displaced amacrine cells. Recent data show that OHT results in a protracted insult to the inner and outer retina that causes functional alterations and ultimately, degeneration and death of cones.