A borderline premature infant was referred to us for routine ophthalmological examination because routine antenatal ultrasound scan showed unilateral ventriculolomegaly. Initial examination revealed unremarkable anterior segments, bilateral inferior optic disc coloboma with subretinal fluid, and white fleck deposits at inferior retina. At nine months of age, nystagmus was detected; left eye was microphthalmic and esotropic – about 30o by Hirschberg estimation. Fundus showed bilateral pale optic discs with inferior optic disc coloboma, macular hypoplasia, nasal retinal detachment (RD) not involving macular in right eye (Web Fig. 1a), and fully detached retina in left eye (Web Fig. 1b). No other family member had a similar problem. Clinical examination during initial presentation revealed subtle dysmorphic features, frontal bossing, prominent occiput, undescended testes, and micropenis (1.5 cm). Patient had hypocortisolism (cortisol 124 nmol/L) and low IGF-1 (43 ng/mL). Other hormones were normal. MRI brain showed ventriculomegaly, atrophic corpus callosum, and absent anterior pituitary gland (Fig. 1a and 1b). Chromosome karyotyping and cytogenetic analysis were normal. He was treated with oral hydrocortisone and intramuscular testosterone. Parents declined further eye treatment.

Fig. 1 Magnetic resonance image (MRI) sagittal plane (a) showing absence of corpus callosum, and axial plane (b) showing mild ventriculomegaly.

Septo-optic dysplasia (SOD), also known as de Morsier syndrome [1], is a rare congenital anomaly with highly heterogeneous phenotype. The causes of this early brain midline dysembryogenesis are unknown, but the most frequently suggested etiologies relate to embryonic vascular insult. Familial cases point to a mutation in a developmental genes (HESX1, SOX2, SOX3) [2]. Diagnosis of SOD involves the presence of two out of the triad of (a) optic nerve hypoplasia, (b) neuro-radiological imaging of midline brain defects (absent septum pellucidum, corpus callosum agenesis), and (c) hormonal deficiency (hypopituitarism) [3]. In our patient, SOD was diagnosed as he had atrophy of septum pellucidum and low level of cortisol, IGF-1 and testosterone. To our knowledge, the association of exudative RD in the setting of SOD has not been previously reported.　Our patient had bilateral optic disc coloboma that may have led to bilateral exudative RD. In optic disc colobomas, the peripapillary retina extends into the anomalous peripapillary scleral defect. The retinal tissue within the defect has been observed to be thinner, incompletely developed, and atrophic; and sometimes the retina is detached in this area. A few cases of SOD associated with persistent fetal vasculature, peripheral retinal non-perfusion and neovascularization have been earlier reported [4,5].