The optic nerve carries the electrical impulses from the eye to the area in the back of the brain where vision is sensed and interpreted. Injury to the optic nerve usually leads to partial or complete loss of sight.

Optic Nerve Hypoplasia

Failure of the optic nerve to develop fully (optic nerve hypoplasia) in kittens may result from infections with panleukopenia (feline distemper, a viral infection) while in the mother's womb. The condition may occur in only one eye or both, and it can occur with or without other eye abnormalities. If the optic nerves of both eyes fail to develop, the newborn will be blind. Involvement of only one of the optic nerves often goes undetected or may be discovered later in life if the other eye acquires a blinding disease.

Optic Atrophy

Optic degeneration or atrophy may occur after glaucoma, trauma, advanced degeneration of the retina, prolonged low blood pressure within the eye, or inflammation. The optic disk appears flattened and smaller than normal; it is often colored, with very noticeable reduction in the optic nerve and blood vessels of the retina. The pupil of the eye will not react to light and vision is absent. There is no treatment.

Last full review/revision July 2011 by Kirk N. Gelatt, VMD; David G. Baker, DVM, MS, PhD, DACLAM; A. K. Eugster, DVM, PhD