Birdshot Chorioretinopathy

Abstract

Birdshot chorioretinopathy (BSCR) is a rare, bilateral, posterior uveitis with a chronic course. BSCR has a very strong association with HLA-A29, with approximately 96% of patients testing positive (Shah et al. 2005). The first report of BSCR has been credited to Franceschetti and Babel in 1949, who described a patient with multiple hypopigmented choroidal lesions as having “chorioretinopathy with candle wax spots” (Franceschetti and Babel 1949). Ryan and Maumenee coined the name “birdshot retinochoroidopathy” in their 1980 case series of 13 patients. The clinical findings in their patients included creamy chorioretinal lesions, macular edema, disc edema, and vitreous debris with minimal anterior segment inflammation (Ryan and Maumenee 1980). In 1981, Gass further characterized the syndrome, but chose the name “vitiliginous chorioretinitis,” due to the similarity of the fundus findings in the skin of patients with vitiligo. This description of BSCR also recognized the development of nyctalopia, dyschromatopsia, and electroretinographic abnormalities as the disease progressed (Gass 1981). Consensus criteria for the definition of BSCR have been developed (Table 7.1), which closely resemble the clinical findings noted in these early studies (Levinson et al. 2004). Since the first comprehensive descriptions in the early 1980s, many advances have been made in our understanding of the genetics, pathogenesis, and treatment of BSCR. This chapter summarizes our current understanding of BSCR, with a focus on the role of fundus examination and chorioretinal imaging techniques to diagnose BSCR, assess disease activity, and monitor progression.