Birdshot chorioretinopathy (BSCR) is a relatively rare form of uveitis, which is strongly correlated with the histocompatibility leukocyte antigen (HLA)-A29 class I type. Nevertheless, HLA typing is not diagnostic. The purpose of the present study was to retrospectively evaluate the ocular manifestations associated with the presence of HLA-A29 other than typical BSCR. Charts of consecutive patients with a diagnosis of intraocular inflammation and who were found to be positive for the presence of HLA-A29 were retrospectively reviewed. Only 7 patients met the criteria for a definite diagnosis of BSCR. Among the other 11 patients, the disease was bilateral in 7 patients and unilateral in 4 patients. A definite diagnosis of the following conditions were found: intraocular and CNS lymphoma in 1 patient, posterior tubercular uveitis with occlusive vasculitis in 1 patient, latent ocular tuberculosis in 1 patient, Fuchs' uveitis in 1 patient, herpetic panuveitis in 1 patient and HLA-B27 anterior uveitis in another patient. Although BSCR is strongly related to the HLA-A29 phenotype, and its presence confers a relative risk of disease, the definite diagnosis requires specific ocular characteristics. HLA-A29 typing alone is not a diagnostic requirement for the definite diagnosis of BSCR and should only be considered as a supportive finding.
Keywords: Birdshot chorioretinopathy; Epidemiology; HLA-A29; Uveitis.