Optic nerve: Atypical nerves and nerve findings

It is now well recognized that structural changes in the head of the optic nerve often precede functional changes detected by perimetry. The evaluation of the optic disc has therefore become increasingly important in the diagnosis and management of glaucoma, with an emphasis on early detection of the disease. As it contains the neural fibers of the optic nerve, the appearance, contour and substance of the neural rim, and inversely the extent of the optic cup, generally hold the examiner's primary attention. However, other manifestations of glaucomatous optic neuropathy may also be useful in the detection and monitoring of glaucoma. These include PPA. Peripapillary atrophy refers to a white or pigmented crescent-shaped area adjacent to the head of the optic nerve. As its name suggests, it represents atrophy of pre-existing tissue, here the chorioretinal tissue overlying the peripapillary sclera- which is considered by many to be secondary to the glaucomatous process. The atrophy may be confined to a small area adjacent to the disc, often temporal, or inferior and temporal. It may also be extensive and surround the disc concentrically for some distance. In glaucoma patients, its extent may be correlated with the amount of nerve rim loss and field loss [1].