Isotretinoin-related optic disc swelling

A 19-year-old Asian woman presented to eye casualty via her optician. She complained of a 3-week history of an intermittent 'misty' patch in her left vision. This lasted less than 5 seconds at a time and occurred more frequently in the mornings. There were no other symptoms and she was systemically well. The patient was currently in the 11th week of a 16-week course of oral isotretinoin for recalcitrant acne, but was on no other medication. She had been using oral tetracycline until I year previously. Examination revealed visual acuities of right 6/6, left 6/9 with pharmacologically dilated pupils. Clinical examination was unremarkable (including normal ocular movements, visual fields to confrontation, colour vision and cranial nerves) with the exception of grossly swollen optic discs, left greater than right (Figure 1). The isotretinoin therapy was stopped and blood tests, Goldman visual fields (Figure 2), Heidelberg retinal tomography (Figure 3), computed tomography (CT) scan of the head and electro-diagnostic tests (EDTs) were arranged. Fields showed an enlarged left blind spot but no other abnormality, Blood tests showed elevated cholesterol, alkaline phosphatase and alanine aminotransferase levels. CT head scan revealed no intracranial abnormality and EDTs were normal. Neurology review corroborated a diagnosis of drug-induced raised intracranial pressure and lumbar puncture was felt to be unnecessary. Eleven weeks later the patient was asymptomatic with a clear reduction in the swelling of both discs. Liver function tests and Goldman visual fields were returning to normal. The patient remains asymptomatic and under regular review.