Congenital aplasia of the optic chiasm presenting as optic nerve hypoplasia with no other ocular or systemic comorbidity.

We introduce a case of an infant girl who presented to our paediatric ophthalmology department with no behavioural response to visual targets and horizontal nystagmus. An ocular assessment revealed isolated bilateral small optic discs prompting further investigation. Her biochemical and endocrinological profiles were normal but a head MRI identified a total absence of the optic chiasm and optic tracts. Electrodiagnostic tests confirmed the diagnosis of aplasia of the optic chiasm. Our patient had no systemic comorbidities and has shown excellent milestone progression. She is now in a mainstream school with support advancing into higher levels of the Braille system. Our case highlights the importance of thorough investigation to identify the salient features of the condition and establish a differential diagnosis early which helped to facilitate sufficient social support to aid with the patient's development.