13th February 2025

A 73-year-old woman presents with a red eye.

A 73-year-old woman presents with a red eye. She has well-controlled bipolar disorder, a metallic aortic valve replacement and reflux disease, for which she has recently undergone H. Pylori eradication.

Observations are within normal limits. She has a bright red patch on the surface of her left eye. Her eye is not painful and she has no visual impairment.

Which investigation is most likely to explain this presentation?

Select the SINGLE most appropriate option from the list below. Select ONE option only.