Ganglionic neuroretinal aplasia and hypoplasia: aplasia and hypoplasia of optic nerve.

A new clinical feature, DM/DD (distance between the centers of the disc and the macula/disc diameter) ratio, of the hypoplasia of the optic nerve is described. Two cases of hypoplasia, one unilateral and one bilateral, and one case of pseudohypoplasia or micropapilla (small discs with normal function) are reported. On the basis of the underlying defect (the failure of the development of the ganglion cells in the retina), it is suggested that this entity should be called ganglionic neuroretinal hypoplasia and aplasia (when all the ganglion cells are missing). For the same reason it is proposed that this entity should be included in the discussion of the retinal disorders. Also this entity should be differentiated from the small discs with normal function (pseudo-hypoplasia or micropapilla). A classification of ganglionic neuro-retinal hypoplasia is given and associated ocular anomalies are mentioned.