Optic nerve hypoplasia

Optic nerve hypoplasia, abbreviated ONH, is a medical condition arising from underdevelopment (hypoplasia) of one or both optic nerves, and it is the most common congenital optic nerve anomaly. The optic disc appears abnormally small because not all the optic nerve axons have developed properly. The optic nerve carries visual signals from the retina to the brain and has approximately 1.2 million nerve fibers in the average person; in people diagnosed with ONH there are noticeably fewer. The condition is often associated with endocrinopathies (hormone deficiencies), developmental delay and brain malformations, so it is frequently assessed together with those findings rather than as an isolated eye problem.