Background: Septo-optic dysplasia (SOD) or de Morsiers’s syndrome is a rare congenital disorder characterized by optic nerve hypoplasia, hypothalamic-pituitary axis hypoplasia, and midline abnormalities of the brain, agenesis of septum pellucidum and corpus callosum. Initially, it was described in 1941 by Reeves and further discussed by the French-Swiss neurologist de Morsier in 1956. The phenotype of SOD is highly heterogeneous, and the existence of at least two features is considered sufficient for diagnosis. Objective: The aim is to emphasize the importance of including SOD in the differential diagnosis of young patients, presenting with strabismus, especially if very low vision is documented in one or both eyes. Case report: In this case, a 13-year-old male presented to our institution with a complaint of deviating left eye outwards in the last few years. During the examination, left eye exotropia, as well as low visual acuity (light perception) of the left eye were documented. The findings of the right eye were normal and visual acuity was 1.0. Magnetic resonance imaging, optical coherence tomography, and fundus photography revealed optic nerve, brain midline, and retinal abnormalities. The patient was diagnosed as having SOD with optic nerve hypoplasia, septum pellucidum agenesis, and hypothalamic-pituitary axis hypoplasia. Conclusion: Although SOD is not curable, many aspects of this syndrome can be improved through a multidisciplinary approach consisting of hormonal replacement, corrective ophthalmological surgery, as well as neuropsychological treatment, and support if necessary.
Key words: optic nerve hypoplasia, septo-optic hypoplasia, de Morsier’s syndrome, septum pellucidum hypoplasia, hypopituitarism, congenital disorder.