Optic Nerve Hypoplasia: Ocular Genetic Studies

Optic nerve hypoplasia (ONH) is the most common congenital optic nerve anomaly characterized by a deficiency in the number of retinal ganglion cell axons due to incomplete development of the optic nerve. ONH is typically characterized by decreased visual acuity and visual field loss. Although ONH can occur in isolation, it is often associated with various neurodevelopmental disorders, brain malformations and systemic pathologies. Although the etiology is unknown in most cases, some genetic and environmental factors have been identified. Recent advances in genetic studies have emphasized the genetic heterogeneity of ONH. While many cases occur sporadically, a significant proportion are due to identifiable genetic causes, often involving de novo mutations.