Optic Nerve Hypoplasia and Autism: Common Features of Spectrum Diseases

Cassandra Fink and Mark Borchert Autism is a developmental disorder characterized by impaired social interaction, problems in verbal and nonverbal communication, and stereotyped or repetitive activities and interests. Rather than a single condition, autism is today generally regarded as consisting of a spectrum of pervasive developmental disorders that together are known as autism spectrum disorders (ASDs). Optic nerve hypoplasia (ONH) is a congenital condition characterized by underdeveloped optic nerves and neurological impairment involving endocrine dysfunction and developmental delay, with or without brain malformations that are visible by way of neuroimaging tools. Increasing in prevalence, ONH is now the leading single ocular cause of blindness in children in the developed world, affecting 10.9 per 100,000 births (Patel, McNally, Harrison, Lloyd, & Clayton, 2006; Hatton, Schwietz, Boyer, & Rychwalski, 2007). Clinical observations and recent reports indicate a high frequency of ASDs in children with ONH (Ek, Fernell, & Jacobson, 2005; Parr, Dale, Shaffer, & Salt, 2010). In children with ONH, there are additional characteristics of ASD beyond those attributable to visual impairment alone, such as echolalia and stereotypic motor movements. We argue that ONH, like ASDs, should be considered a spectrum disorder to account for the range of severity in outcomes and symptoms associated with this condition. In addition, we believe the similarities in the two conditions illustrate the possibility of a shared neurodevelopmental origin. Comparing the similarities in these conditions may lead to a greater understanding of the risk factors contributing to either condition, as well as potential clinical outcomes, as the relationship is further explored.