Optic nerve hypoplasia may be inherited in Miniature Poodles; in kittens and calves, it may result from in utero infections with panleukopenia and bovine viral diarrhea, respectively. In calves, the cause may be maternal avitaminosis A. The condition may be unilateral or bilateral, and it can occur with or without other ocular anomalies. Bilateral involvement is manifest as blindness in the neonate; unilateral involvement is often an incidental finding later in life or becomes manifest if the other eye acquires a blinding disease.
Papilledema is infrequent in animals and often associated with orbital masses. Increased intracranial pressure does not usually result in papilledema in animals, except in calves with avitaminosis A. The optic disk appears raised above the surface of the adjacent retina, and venous congestion is present. Vision and the light pupillary reflexes are not usually affected unless optic atrophy develops.
Optic atrophy may develop after glaucoma, trauma, advanced retinal degeneration, prolonged ocular hypotension, or inflammation. The optic disk appears depressed and smaller than normal; it is often pigmented, with marked reduction in the optic nerve and retinal vasculature. Both direct pupillary reflex and vision are absent. There is no treatment.
Last full review/revision July 2011 by Kirk N. Gelatt, VMD