Birdshot retinochoroidopathy

Abstract

Birdshot retinochoroidopathy (BSRC) is an uncommon, but well-characterized chronic, bilateral posterior uveitis, which is uniquely associated with the human leukocyte antigen-A29 phenotype. The disease presents predominantly in middle-aged Caucasian females who complain of blurred vision, floaters, photopsias, paracentral scotomas and nyctalopia. While autoimmune mechanisms are thought to play an important role in the pathogenesis of BSRC, its etiology remains unknown. Important questions remain in our understanding of BSRC with respect to its pathogenesis, epidemiology, optimal treatment, and prognosis, including the determinants of remission and relapse, as well as the best strategy for monitoring disease activity, progression and response to therapy with electroretinographic and psychophysical testing, established and emerging imaging modalities, and peripheral cytokines profiles.

Keywords: Immunomodulatory Therapy; Monitoring; Multi-modal Imaging; Pathogenesis.

Figure 1

Fundus photograph of a patient with birdshot retinochoroidopathy. The lesions are typically at the level of the choroid or retinal pigment epithelium; ovoid, cream-colored with indistinct borders. They are between 50 and 1,500 μm in size with a characteristic nasal, radial distribution in the postequatorial fundus.

Figure 2

Fluorescein angiographic findings in birdshot are inconsistent and depend on the age of the lesions and the phase of the study. Early birdshot lesions (a) demonstrate early hypofluorescence with subtle late staining. In the later stages of the angiogram (b), leakage at the optic nerve is typically seen as a segmental periphlebitis. Cystoid macular edema and choroidal neovascularization may also be evident.

Figure 3

Indocyanine angiography in birdshot retinochoroidopathy reveals hypo-fluorescent spots in both the early phases of the study (a), as well as the late phases of the study (b) that are more numerous than those seen on fluorescein angiography.