Congenital optic nerve hypoplasia.

Congenital optic nerve hypoplasia (CONH) is an increasingly recognized cause of low vision in children. The spectrum of ophthalmoscopic and clinical presentations of CONH is described here with illustrative cases. Some children with unilateral CONH develop a secondary, functional amblyopia that may respond to patching during visual development. Children with bilateral CONH, poor vision and nystagmus usually present early and have a high risk of exhibiting central nervous system (CNS) malformations and treatable endocrine deficiencies.