30th April 2024

A 55-year-old man presents with progressive loss of vision in his left eye.

A 55-year-old man presents with progressive loss of vision in his left eye. He describes a ‘shadow’ coming from the left side that is worsening over time. There is no pain or redness in the eye. He has a history of hypertension but no other significant medical history. On examination, his right eye appears normal, but the left eye has a noticeable loss of vision on the left side.

Which investigation is most likely to reveal the underlying cause of his visual field defect?