Programme for ocular inflammation & infection translational research (PROTON) registry: Cross-sectional analysis of baseline patient characteristics

Purpose: The Programme for Ocular Inflammation & Infection Translational Research (PROTON) registry collects real-world data on infectious and non-infectious ocular inflammatory diseases (OID) to enhance understanding of disease progression and treatment outcomes. This report presents the baseline characteristics of patients enrolled in two international multicentric studies, OASIS 1 and OASIS 2, over the first two years. Design: A cross-sectional observational study. Methods: PROTON is an observational ambispective cohort registry comprising OASIS 1, a retrospective study (2000–2021), and OASIS 2, a prospective study (2021 onwards). Data is collected at multiple intervals over a 10-year period, focusing on various OID. Participants include patients diagnosed with anterior uveitis, intermediate uveitis, posterior uveitis, panuveitis, scleritis, retinal vasculitis, and neuroretinitis. Baseline characteristics, ocular examinations, and treatment outcomes are recorded. Results: A total of 2640 patients (3642 eyes) have been recruited across 17 centers worldwide. Infectious was the most common etiology (31.6 %), followed by idiopathic (28.1 %), undetermined (21.7 %), and non-infectious (16.0 %). Most patients (54.8 %) were male, with anterior uveitis being the most common anatomical location (37.5 %). Visual impairment was present in 53.2 % of cases, with 18.8 % experiencing moderate (0.5–1.0 LogMAR) and 22.6 % severe impairment (>1.0 LogMAR). Tuberculosis (64.0 %) and toxoplasmosis (13.5 %) were the leading infectious causes, while HLA-B27-associated uveitis accounted for 19.4 % of non-infectious cases. Conclusions: The PROTON registry provides valuable insights into the global spectrum of OID, with a substantial representation of infectious causes. This real-world evidence highlights the key prevalence of visual impairment and underscores the importance of research on this topic. As the registry evolves, it will help refine clinical management strategies and improve patient outcomes globally.