A Pediatric Case of Buried Optic Disc Drusen Accompany with Non-organic Visual Dysfunction

Abstract

　A 9-year-old girl was referred to our hospital with a complaint of decreased visual acuity in the right eye and orbital pain. At the initial visit, her visual acuity was 0.8 in the right eye. On examination, we could not confirm a relative afferent pupillary defect owing to excessive blinking. Dilated fundoscopic examination revealed optic disc swelling in the right eye with a normal-appearing disc in the left eye. Goldmann perimetry revealed expansion of Marriott’s blind spot to the macular region. Fluorescein angiography revealed hyperfluorescence of the right optic disc; however, brain magnetic resonance imaging did not reveal any abnormalities. Steroid pulse therapy was administered based on a high index of clinical suspicion for optic neuritis. Despite complete recovery of the visual field, her visual acuity and optic disc swelling remained unchanged. We suspected buried optic disc drusen（ODD）based on ultrasonographic findings of a bright echo pattern. Follow-up Goldmann perimetry revealed a spiral pattern, suggesting non-organic visual dysfunction. We report a rare case of unilateral buried ODD. The diagnosis of buried ODD is challenging, particularly in unilateral cases, because this condition mimics optic edema. Non-organic visual dysfunction should be considered in the differential diagnosis even in cases of organic disorders.