Birdshot retinochoroidopathy and HLA-A29+ and HLA-A29- idiopathic retinal vasculitis: comparative study of 56 cases.

We reviewed the records of 20 patients with birdshot retinochoroidopathy and 36 patients with idiopathic retinal vasculitis. The numbers of patients with the HLA-A29 phenotype were 19 (95%) and 22 (61%) respectively. Overall, similar findings were noted in the birdshot retinochoroidopathy group and the HLA-A29+ idiopathic vasculitis group: more posterior pole involvement, more severe course and poor visual prognosis despite intense corticosteroid therapy. In contrast, the patients with HLA-A29- idiopathic vasculitis showed more peripheral involvement, the course was less severe and the prognosis was better; smaller amounts of steroids were used. Only one patient with HLA-A29+ idiopathic vasculitis eventually presented with signs of birdshot retinochoroidopathy; complete cure was obtained in other cases. Our results suggest the existence of an HLA-A29 syndrome encompassing birdshot retinochoroidopathy as well as other conditions whose expression would be determined genetically.