Reversible visual loss in biopsy-proven giant cell arteritis

A late 60s man presented with a 1-week history of recurrent transient monocular visual loss in his left eye, followed by sudden, severe visual loss and eyelid pain. Examination revealed a left relative afferent pupillary defect and segmental chalky-white oedema of the superior half of the optic disc. During admission, he experienced repeated episodes of no light perception in the left eye. A systematic review revealed jaw claudication, low-grade fever and scalp tenderness. Inflammatory markers were elevated and temporal artery ultrasound showed vessel wall thickening and stenosis. Extensive work-up for embolic and inflammatory causes of transient visual loss, including carotid Doppler, echocardiography, brain and vascular MRI and serology for myelin oligodendrocyte glycoprotein and AQP4 antibodies, was unremarkable. Temporal artery biopsy confirmed giant cell arteritis. Intravenous methylprednisolone 1 g/day for 3 days, followed by high-dose oral prednisolone, led to substantial visual recovery, with best-corrected acuity improving to 20/63. This case highlights that even severe, evolving visual loss with segmental chalky disc oedema in giant cell arteritis may be partially reversible if recognised promptly and treated emergently.