Optic Neuropathy

Abstract

Optic neuropathy, or damage to the optic nerve, is diagnosed by characteristic visual field loss, color vision deficit, decreased brightness sense, afferent pupillary defect, nerve fiber layer dropout, optic nerve pallor, or optic nerve swelling. Optical coherence tomography (OCT) can demonstrate optic neuropathy by exhibiting decreased nerve fiber layer thickness, ganglion cell layer complex loss, or nerve fiber layer swelling. OCT can also show normal outer retinal structure and thereby aid in localizing the problem to the optic nerve. Visual field loss in optic neuropathy reflects the nerve fiber course thru the retina. Cecocentral visual field loss, as seen in nutritional optic neuropathy, autosomal dominant optic neuropathy, ethambutol toxicity, and optic neuritis, reflects damage to the so-called papillomacular bundle and is accompanied by decreased color vision (as measured by color plates, e.g., AO/HRR color plates) and decreased central acuity. In optic neuropathy accompanied by cecocentral visual field loss, color vision loss is markedly decreased compared to visual acuity.