Septo-Optic Dysplasia: A Case Series of 33 Patients

The objective of this study was to record the clinical, neuro-radiological, and systemic features of patients with septo-optic dysplasia (SOD). A retrospective review of patients was conducted to identify patients with features consistent with SOD over a 6-year period, including optic nerve hypoplasia with agenesis of midline structures, along with an absent septum pellucidum and/or agenesis of the corpus callosum. Thirty-three patients were identified. The male to female ratio was 2:1, while the median age at diagnosis was 5 years (interquartile range = 10 years, range = 0-44 years). Optic nerve hypoplasia (ONH) was bilateral in 81.81% of cases (n = 27) and unilateral in 18.18% of cases (n = 6), with three cases in each eye. Developmental delay was documented in 24.2% (n = 8). The most frequent magnetic resonance imaging features that were consistent with SOD included: isolated absent septum pellucidum reported in 51.51% (n = 17); isolated corpus callosum agenesis in 33.33% (n = 11); and both absent septum pellucidum and corpus callosum agenesis in 15.15% (n = 5). Pituitary gland abnormalities, including pituitary hypoplasia in 9% (n = 3) or hypoplasia of pituitary infundibulum in 6% (n = 2) were less common. Pituitary hormonal abnormalities were present in 50% of the 10 tested patients (n = 5). Although bilateral ONH is more frequent, hypoplasia of just one optic nerve could be a presenting feature of SOD. Therefore, additional neuro-imaging is important for a diagnosis in cases of unilateral and bilateral ONH and a multidisciplinary approach is beneficial.