Early and sustained treatment modifies the phenotype of birdshot retinochoroiditis

In this single-centre retrospective case review, we investigate the long-term follow-up of birdshot retinochoroiditis (BRC) patients, analysing the impact of early, vigorous, and prolonged treatment on the evolution of indocyanine green angiography (ICGA) signs and fundus appearance. Treatment delay was calculated for each BRC patient, and patients were classified into two groups—treatment delay of <10 months (early-treatment group) and treatment delay of >10 months (delayed-treatment group). Fundus photographs and ICGA frames from the initial visit and from the last follow-up visit were assessed. Fundus photographs were evaluated for the presence of at least three circumpapillary, typical, rice-shaped birdshot lesions in one eye, inferior or nasal to the optic disc. ICGA pictures were evaluated for the presence of lesions (hypofluorescent dark dots, fuzziness). Differences were compared between the two groups and between the first visit and the last follow-up visit. In the early-treatment group, 5/6 patients had no characteristic BRC fundus lesions, but 7/7 patients in the delayed-treatment group displayed typical lesions. At last follow-up, 5/6 early-treatment patients showed no fundus lesions, and 6/7 delayed-treatment patients retained their fundus lesions. At presentation, all 13 patients exhibited lesions on ICGA. At last follow-up, ICGA lesions had completely disappeared in 4/6 early-treatment patients and 3/7 delayed-treatment patients. Thus, early and sufficiently dosed inflammation-suppressive treatment can prevent the appearance of typical BRC fundus lesions. It is therefore crucial to perform ICGA to detect otherwise occult stromal choroiditis in suspected BRC cases and to initiate adequate therapy immediately.