Hypoplasia of the optic nerve.

Hypoplasia of the optic nerve is uncommon (Scheie and Adler, I94I; Somerville, I962; Whinery and Blodi, I963; Ewald, I967). It is usually due to a failure of development of the ganglion cell layer of the retina and results in a small but discernible optic disc with central vessels. The disc may be cupped with a peripapillary, mottled, yellowish halo corresponding to the size of the normal disc, and the nerve fibre layer of the retina and axis cylinders of the optic nerve are absent (Scheie and Adler, I941; Whinery and Blodi, I963; Helveston, I966; Ewald, I967). The following is a case of unilateral hypoplasia of the optic nerve in a child who was otherwise normal.