[Bilateral blindness after injury in a riding horse]

Bilateral blindness was diagnosed in a 5-year-old Hanoverian gelding presented for evaluation of a corneal opacity in one eye. About 12 months prior to the examination, the gelding had fallen head over, hitting his head and the cornea. Clinical and electroretinographic findings as well as pathohistologic and ultrastructural lesions of both eyes including the optic nerves are presented. Ophthalmoscopically visible pigment disruption of the non-tapetal fundus adjacent to the optic discs correlated morphologically with foci of degeneration and atrophy of the retina, whereas ophthalmoscopically visible accumulation of pigment was morphologically characterized by hypertrophy of the pigment epithelium, increased intracellular pigment accumulation and by migration of pigment cells into the inner lamina of the retina. Severe atrophy of the retinal neuronal layer was linked to traumatic optic nerve degeneration.