Indocyanine green angiography in birdshot chorioretinopathy

Objective: Birdshot chorioretinopathy (BC) is an ocular inflammatory diseas e involving both the retina and the choroid. The study goal was to evaluate indocyanine green angiographic features in BC to assess choroidal involvem ent. Design: Retrospective, observational case series. Participants: Fifty-two patients with BC documented with at least 1 concomi tant fluorescein and indocyanine green angiogram. Intervention: Indocyanine green angiography (ICGA) was performed according to a standard protocol used for inflammatory disorders. Main Outcome Measure: Iindocyanine green angiographic signs were correlated with fundus photographs, fluorescein angiography, degree of inflammatory a ctivity, and stage of disease. Results: In active disease, three main features were observed. The principa l finding, found in 100% of patients, was the presence of hypofluorescent d ark dots during the intermediate phase of angiography; their evolutionary p attern was twofold, becoming either isofluorescent or remaining hypofluores cent at the late phase of angiography. The other two signs were fuzzy, indi stinct choroidal vessels and late-diffuse choroidal hyper-fluorescence. In chronic longlasting disease, the characteristic finding was the presence of hypofluorescent dark dots that persisted in the late phase of disease and is theorized to correspond either to chorioretinal atrophy (irregular geogr aphic pattern) or to persistent choroidal granulomas (round oval form). Conclusions: Consistent ICGA findings in 52 patients allowed the authors to establish a fairly precise ICGA semiology for BC. This procedure enabled t he authors to assess choroidal involvement, and, in selected cases, it also was found to be of diagnostic help and useful to monitor therapeutic inter vention.