To determine whether failure to recognize ocular vascular ischemia in patients aged ≥50 years presenting with isolated ocular symptoms leads to missed diagnoses of “stroke of the eye” due to giant cell arteritis (GCA), and to evaluate the role of temporal artery ultrasound (TAUS) as a real-time diagnostic tool in the emergency department (ED).

GCA is a common, treatable, large-vessel vasculitis that can cause irreversible blindness if not promptly diagnosed. Occult GCA-presenting without systemic symptoms-may account for up to one-third of cases in patients with acute ocular ischemia such as central retinal artery occlusion (CRAO) or ischemic optic neuropathy (ION). Despite recommendations supporting imaging, TAUS remains underused in ED workflows for ocular presentations.

A retrospective cohort study was conducted using data from the University of Kentucky (UKY) Epic EHR and the Epic Cosmos national database (299 million patients). Patients aged ≥50 years presenting between 2021 and 2024 with isolated ocular symptoms were analyzed. Diagnostic testing included TAUS, temporal artery biopsy (TAB), and corticosteroid administration prior to testing. Multivariable logistic regression identified independent predictors of GCA diagnosis, adjusting for TAUS, TAB, and steroid use.

Among 103 UKY patients with isolated ocular symptoms, 38.8% had confirmed GCA; 67.5% underwent TAUS and 17.5% TAB. Steroids were administered pre-testing in 64%, and 69.7% of these tested negative. TAUS was the strongest independent predictor of GCA (OR 12.74; 95% CI 7.04–23.05), outperforming TAB (OR 4.68; 95% CI 1.57–13.99). Model AUC was 0.71. In Epic Cosmos, 62-94% of patients with ocular ischemia (CRAO or ION) received no GCA testing.

Recognition of GCA in the ED remains inadequate. TAUS offers immediate, noninvasive, point-of-care diagnostic capability and may bridge critical delays in diagnosing ocular ischemia due to GCA. Integration of TAUS into ED stroke protocols could prevent irreversible blindness.