29th April 2024

A 30-year-old woman presents with a sudden loss of vision in her left eye over the past three days.

A 30-year-old woman presents with a sudden loss of vision in her left eye over the past three days. She describes the vision loss as a dark curtain descending over her eye. She also reports pain on moving her left eye. Her medical history is unremarkable, and she is not on any medication. On examination, her visual acuity is reduced to counting fingers in the left eye. The swinging flashlight test shows a relative afferent pupillary defect in the left eye. 

Which is the most likely diagnosis?