MRCP2-4732

MRCP2-4732

A 72-year-old woman presents with vision loss in her right eye, accompanied by pain while chewing and a persistent headache. Upon examination, her visual acuity is 6/60 in the affected eye, and ophthalmoscopy reveals a swollen, pale optic disc. Her blood work shows a low hemoglobin level of 115 g/L, high platelet count of 545 * 109/L, elevated white blood cell count of 11.1 * 109/L, and an elevated ESR of 45 mm/hour. Her HbA1c level is also high at 82 mmol/mol. She has a history of hypertension and diabetes mellitus, and has not been keeping up with retinal screening. What is the most likely cause of her vision loss?