HLA-B27-related uveitis and seasonal variation-an Indian perspective.

Purpose To study seasonal variation and systemic associations in HLA-B27 related uveitis (HBU). Methods This was a retrospective, observational chart review conducted in a single, tertiary eye care hospital, from January 2015 to December 2019. New cases presented from January 2017 to December 2019 were studied for incidence patterns (Group X). Cases with ≥1-year follow-up were studied for systemic association (Group Y) and cases with ≥4 episodes of active uveitis were studied for recurrence pattern (Group Z). A year was divided into 3 segments of the year (SoY): 1. November-February, 2. March-June, 3. July-October. Results We found 157 cases of HBU from January 2015 to December 2019. The incidence in Group X (n = 105) was found to be least in SoY 2 in all 3 years (2017-2019). In Group Y (n = 85), 39 cases (45.88%) were diagnosed as spondyloarthropathies, among which 20 were of ankylosing spondylitis (23.52%). More than 1/2 the total number of episodes occurring in the same SoY (SoY Max), in Group Z (n = 25), was seen in 14 (56%) cases. SoY Max was the first segment (SoY 1) for most of these cases (n = 7). In Group Z, 8 (32%) patients were on immunomodulatory therapy at presentation. Conclusion Our study confirms seasonal variation in HBU patients by documenting the least incidence from March to June and identifies 56% of patients that can have a maximum number of recurrences in a specific season of the year. Outcomes of surgical interventions planned accordingly, and responsible environmental factors for HBU should be studied further.