Assessment of Giant Cell Arteritis-Associated Visual Outcomes at a Tertiary Hospital in Ontario, Canada.

OBJECTIVE: There are limited data concerning outcomes in those with giant cell arteritis (GCA)-associated vision changes (GCAVCs). We estimated the association of intravenous (IV), compared to oral, glucocorticoids (GCs) with outcomes in GCAVCs. METHODS: We conducted a retrospective cohort study at a tertiary healthcare facility in Ontario, Canada. Individuals aged ≥ 50 years with an International Classification of Diseases, 10th revision, diagnostic code for GCA associated with a healthcare visit between November 2017 to December 2023 were identified for inclusion. Diagnoses of GCA were verified as the final diagnosis of the treating clinician and were required to be supported by histologic, radiographic, and/or biochemical evidence of inflammatory vasculopathy. GCAVCs were identified by clinical assessments. Treatment exposures were defined as whether the individual was first exposed to IV or oral GCs. The primary outcome was reported visual improvement after treatment. We used logistic regression to estimate treatment effects, adjusting for demographic and disease factors. RESULTS: In 289 patients with GCA, 77 (26.6%) had GCAVCs. Of these, 70.1% of GCAVCs led to permanent vision loss, and visual recovery was seen in 16% of participants. We found no difference in outcomes for those first treated with IV vs oral GCs (adjusted odds ratios 0.43-1.72; 95% CI 0.02-123.68). CONCLUSION: GCAVCs are common and frequently associated with permanent vision loss. Although the precision of our results was limited by sample size, we did not find evidence that receiving IV GCs before oral GCs was associated with visual improvement in GCAVCs.