The Prevalence of Brain Abnormalities in Japanese Patients with Optic Nerve Hypoplasia

The purpose of this study was to investigate the clinical characteristics of Japanese patients with optic nerve hypoplasia (ONH), with particular attention to the prevalence of brain abnormalities. We retrospectively analysed the medical charts of 16 patients who were diagnosed with ONH and who underwent magnetic resonance imaging (MRI) at Niigata University Medical and Dental Hospital. We recorded the age, sex, laterality, initial eye and visual symptoms, best-corrected visual acuity, and brain abnormalities on MRI (excluding ONH). The median age at the first visit to the Ophthalmology Clinic was 2.4 years old. Four patients were male and 12 were female. ONH was bilateral in 11 patients and unilateral in five. Best-corrected visual acuity ranged from no light perception to 20/20. Seven patients (43.8%) had brain abnormalities including agenesis of the septum pellucidum, pituitary gland hypofunction, cerebral dysplasia, and West syndrome. Five of these seven patients had general manifestations since the neonatal or infantile period. Our study revealed the prevalence of brain abnormalities associated with optic nerve hypoplasia in Japanese patients at a single institute. Because two of 11 patients had no general manifestations since the neonatal or infantile period but demonstrated brain abnormalities, MRI should be performed to investigate all patients with ONH.