SIGNIFICANCE Morning glory disc anomaly is a congenital abnormality of the optic disc. Optical coherence tomography angiography shows vascular rarefaction of the superficial and deep capillary plexuses and increased vascularity of the radial peripapillary capillary plexus. We hypothesize that this congestion represents a compensatory mechanism to an abnormal vasculogenesis. PURPOSE The aim of this study was to describe the optic disc vascular alterations occurring at choriocapillaris and retinal vascular plexuses in a patient affected by bilateral morning glory disc anomaly with optical coherence tomography angiography. CASE REPORT A 24-year-old white man presented for clinical evaluation to our Department of Ophthalmology (San Raffaele Hospital, Milan) complaining of reduced vision in his left eye. Whereas his right eye was unremarkable (20/20), the visual acuity in the left one was limited to 20/30 Snellen equivalent. Funduscopic examination revealed bilateral funnel-shaped optic disc excavation, with a central mass of glial tissue and straight retinal vessels radially emerging from the disc margin, more evident in the left eye; this presentation was considered compatible with bilateral morning glory disc anomaly. Optical coherence tomography angiography of the optic disc disclosed prominent vascular rarefaction of the peripapillary superficial and deep capillary plexuses and choriocapillaris, with an increased vascularity of the radial peripapillary capillary network. CONCLUSIONS Based on these observations, we hypothesize that the congestion of the radial peripapillary capillary plexus might be a compensatory mechanism to the abnormal vasculogenesis occurring in the optic disc of patients affected by morning glory disc anomaly. © Lippincott Williams & Wilkins.