New concepts in the appraisal and management of birdshot retinochoroiditis, a global perspective

Abstract

Birdshot retinochoroiditis (BRC) is a relatively recently described entity. BRC uveitis is predominant in the posterior segment with dual, independent retinal, and choroidal inflammation. The disease has no known extra-ocular inflammation sites and yet features the strongest known HLA association: HLA-A29 is present in close to 100 % of cases. Aim in this mini-review was to readjust the appraisal of BRC in the light of a global approach including the full array of investigational procedures. Historical background and the genesis of the disease name were searched. Global disease description including both the retina and the choroid was given. Retinal involvement was clearly characterized, pointing toward the profuse leakage of retinal vessels of all sizes in early disease and widespread atrophy in under treated patients. The importance of exploration of choroidal disease, unavailable until the early 1990s before the advent of indocyanine green angiography (ICGA) was stressed, allowing early diagnosis of disease. Despite its proven importance to explore the choroid, ICGA is still sparsely used. Existing diagnostic criteria were found to be clearly inappropriate not allowing early diagnosis and are in need to be revised, taking into account both retinal and choroidal aspects of the disease, in order to make early diagnosis possible and hence allow proper management .

Advanced Cases of Birdshot HLA-A29 Retinochoroiditis: Prevalence and Characteristics

“…Our group showed back in 1998, later confirmed by others, that the most appropriate functional parameter to support treatment initiation and to follow evolution was visual field testing rather than visual acuity [4,13,24,25]. Early treatment can lead to an improvement of visual field in parallel with the disappearance of activity signs on ICGA and FA [13]. Prompt treatment was shown to avoid complications such as retinal and choroidal atrophy, as evidenced by OCT and EDI-OCT [16,17].…”

“…In the last decades, increasing evidence became available that the majority of patients needed aggressive and prolonged IST [21,22], with only around 15 % of patients presenting a more benign course [23]. Our group showed back in 1998, later confirmed by others, that the most appropriate functional parameter to support treatment initiation and to follow evolution was visual field testing rather than visual acuity [4,13,24,25]. Early treatment can lead to an improvement of visual field in parallel with the disappearance of activity signs on ICGA and FA [13].…”

“…Diagnosis was made based on the previously published BRC revised diagnostic criteria and included "retinal vasculitis in large or small veins in one or both eyes; vitritis in one or both eyes; ICGA lesions in both eyes (required); and the presence of HLA-A29 antigen (required), with or without oval, depigmented, BRC lesions" [13,14].…”

“…Steroids were then tapered to < 7.5 mg per day, and patients were followed up with visual fields and dual FA/ICGA. In cases of persistent signs of retinal inflammation, or insufficient visual field recovery, a second immunosuppressant or biologic agent was added (usually an anti-TNF-α) [4,13]. On the other hand, if disease was one-sided, unilateral sub-Tenonʼs injection of 40 mg triamcinolone was preferred, a treatment sometimes sufficient in mild cases of BRC, as previously described [26].…”

“…Two findings have since changed our appraisal of BRC: (1) the presence of HLA-A29 antigen reaches nearly 100 % of cases when PCR is used for detection [7 -11] and (2) the possible detection of disease activity in the choroid using indocyanine green angiography (ICGA) before the visible BRC fundus lesions appear [12]. Due to these findings, new diagnostic criteria were established to allow an early diagnosis of BRC [13]: "presence of vitritis and retinal vasculitis in one or both eyes, visual field anomalies in one or both eyes, stromal choroiditis as evidenced by ICGA in both eyes (required), HLA-A29 antigen positivity (required), and the absence of extra-ocular inflammation sites" [13,14].…”