Posterior ischemic optic neuropathy as the main manifestation of giant cell arteritis: a case-based literature review.

This case-based literature review aims to challenge a common misconception that elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels, halo sign on temporal artery ultrasound, and arteritic anterior ischemic optic neuropathy are essential to make a diagnosis of giant cell arteritis (GCA). Here, we present a case of a 70-year-old woman with a biopsy-proven GCA who met the 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology Classification Criteria for Giant Cell Arteritis. On admission she complained of left temporal headache, left scalp tenderness, constitutional symptoms and visual disturbances in her left eye that was diagnosed as posterior ischemic optic neuropathy. Erythrocyte sedimentation rate and CRP levels were within normal limits, and the patient had no halo sign on the temporal artery ultrasound. It is crucial to carefully evaluate visual disturbances in elderly patients, since missing a diagnosis of GCA can have catastrophic consequences, such as bilateral blindness, aortic dissection, stroke, or myocardial infarction.