Aim: To identify the clinical features of optic nerve hypoplasia (ONH) and prevalence within a population of New Zealand children with severe visual impairment.
Methods: Retrospective review of medical records of children with severe visual impairment registered with Blind and Low Vision Educational Network New Zealand.
Results: Of 1500 children with severe visual impairment, 94 (6.3%) exhibited ONH, and 91 (97%) cases were bilateral. Of these 94 cases, 52 (55%) were males and ethnicities were European Caucasian (52%), Maori (40%), Pasifika (6%) and other (2%). Most children with ONH had poor vision, with 60% having ≤ 6/60 Snellen visual acuity equivalent. The median maternal age was 20.0 years old with 52% ≤ 20 years. There was a statistically significant over-representation of Maori ethnicity (40%) and young maternal age with age less than 20 years old (44%) in our cohort compared to the general population (14.6% and 7.4%, respectively; p<0.0001). Half had hypopituitarism, while neuroimaging abnormalities were detected in 60% cases. Cerebral neuroradiographic abnormalities were found to be associated with higher rate of developmental delay (OR 9.764 95% CI 3.246 to 29.373).
Conclusions: This is the first major study of visual impairment in New Zealand children, and it demonstrates that ONH is an important cause of severe visual disability; with an over-representation of Maori children and younger maternal age.
Keywords: Imaging; Optic Nerve.
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