Retinal vessel caliber changes in vasculitis.

ABSTRACT

BACKGROUND: Retinal vasculitis is a potentially sight-threatening inflammation of the retinal vessels, but little is known about the in vivo vascular changes, which occur in affected eyes. The authors therefore sought to measure vessel caliber in eyes with vasculitis. METHODS: Retrospective case-control study. Vasculitis was confirmed using fluorescein angiography. Vessel calibers were measured using validated semiautomated software. RESULTS: There were 21 eyes from 15 patients with vasculitis and 33 control eyes from 21 control subjects. Most cases were diagnosed with idiopathic vasculitis. All had periphlebitis, and one eye also had arteritis. After adjustment for age and gender, mean arteriolar caliber was 143 µm (95% confidence interval [CI], 134-152) in cases and 158 µm (95% CI, 151-165) in controls (P = 0.01). Venular caliber was similar in cases (229 µm; 95% CI, 215-243) and controls (228 µm; 95% CI, 217-234; P = 0.91), whereas arteriole-to-venule ratio was smaller in cases (0.63; 95% CI, 0.60-0.66) compared with controls (0.70; 95% CI, 0.02-0.11; P = 0.004). CONCLUSION: Retinal vasculitis was associated with narrower arteriolar caliber, whereas venular caliber was similar to controls. This resulted in a smaller arteriole-to-venule ratio in eyes with vasculitis.