A prospective evaluation of factors associated with chorioretinitis in patients with West Nile virus infection.

PURPOSE: To identify factors associated with the development and severity of chorioretinitis (CR) in patients with West Nile virus (WNV) infection. METHODS: Prospective study of 38 patients with WNV infection. RESULTS: Simple analysis showed that diabetes (p = 0.027) and age older than 45 years (p = 0.03) were significantly associated with CR. When controlling for age, only association between diabetes and CR remains statistically significant. Diabetic patients' eyes were more likely to have macular involvement (p < 0.0001), 20 or more chorioretinal lesions (p < 0.001), and lesion size 500 microm or more (p < 0.01). CONCLUSIONS: Diabetes was a risk factor for the development and severity of WNV-associated CR.