The clinical time-course of experimental autoimmune uveoretinitis using topical endoscopic fundal imaging with histologic and cellular infiltrate correlation.

PURPOSE EAU is an established preclinical model for assessment of immunotherapeutic efficacy toward translation of therapy for posterior uveitis. Reliable screening of clinical features that correlate with underlying retinal changes and damage has not been possible to date. This study was undertaken to describe, validate, and correlate topical endoscopic fundus imaging (TEFI) with histologic features of murine experimental autoimmune uveoretinitis (EAU), with the intent of generating a rapid noninvasive panretinal assessment of ocular inflammation. METHODS EAU was induced in B10.RIII mice by immunization with the peptide RBP-3(161-180). The clinical disease course (days 0-63) was monitored and documented using TEFI. Disease severity and pathology were confirmed at various time points by histologic assessment. The composition of the cell infiltrate was also examined and enumerated by flow cytometry. RESULTS TEFI demonstrated the hallmark features of EAU, paralleling many of the clinical features of human uveitis, and closely aligned with underlying histologic changes, the severity of which correlated significantly with the number of infiltrating retinal leukocytes. Leukocytic infiltration occurred before manifestation of clinical disease and clinically fulminant disease, as well as cell infiltrate, resolved faster than histologic scores. During the resolution phase, neither the clinical appearance nor number of infiltrating retinal leukocytes returned to predisease levels. CONCLUSIONS In EAU, there is a strong correlation between histologic severity and the number of infiltrating leukocytes into the retina. TEFI enhances the monitoring of clinical disease in a rapid and noninvasive fashion. Full assessment of preclinical immunotherapeutic efficacy requires the use of all three parameters: TEFI, histologic assessment, and flow cytometric analysis of retinal infiltrate.