OPTIC NERVE DISEASES
Optic Nerve Hypoplasia
Optic nerve hypoplasia (ONH) is a congenital condition in which the optic nerve is underdeveloped (small) and is characterized by a decreased number of optic nerve axons. It can present unilaterally or bilaterally.
Ophthalmoscopically, the hypoplastic disc may appear gray or pale in color and is often surrounded by a yellowish mottled peripapillary halo, bordered by a ring of increased or decreased pigmentation. It is often associated with selective tortuosity of the retinal veins.
It is difficult to predict visual acuity potential on the basis of optic nerve appearance.
Visual acuity ranges from 20/20 to no light perception, and affected eyes show localized visual field defects. Nystagmus may be noted when both eyes are involved. The incidence of strabismus is increased with ONH. Electroretinography is...