METHODS: A prospective cohort study was conducted on 66 patients(88 eyes)with active uveitis. The subjects were classified based on the anatomical location of their disease activity as anterior, intermediate, posterior and pan-uveitis. Cycloplegic refraction was performed in both active and quiescent phases, and the results were compared.

RESULTS: Spherical changes in active anterior non-granulomatous uveitis resulted in an average of -0.25(0.77)D(95% CI: -0.5 to 0)shift toward myopia(P=0.039)and in active intermediate uveitis, an average of +0.39(0.8)D(95% CI: 0.09-0.69)shift toward hyperopia(P=0.003). Spherical equivalent changes in active intermediate uveitis resulted in hyperopic shift \〖+0.43(0.94)D, 95% CI: 0.08-0.79, P=0.005\〗. Cylinder had only significant changes in pan-uveitis \〖-0.3(0.39)D, 95% CI: -0.58 to -0.02, P=0.043\〗. In multivariate analysis, we noted that course of disease activity(acute versus recurrent)and anatomical location of disease activity had statistically significant effects on spherical equivalent changes(P=0.003 and P=0.004, respectively).

CONCLUSION: Active uveitis has a significant effect on the refractive status of the eye, the changes of which depend on the inflamed anatomical area.