Dual Margins on Autofluorescence in Tubercular Serpiginous-Like Choroiditis: A Biomarker for Increased Risk of Paradoxical Worsening and the Need for Immunosuppression

Purpose To assess the prognostic role of dual margins on fundus autofluorescence (AF) in predicting treatment outcomes in tubercular serpiginous-like choroiditis (TB SLC). Design Retrospective interventional study. Methods Patients with active TB SLC demonstrating dual hyperautofluorescent margins with an intervening hypoautofluorescent zone on baseline AF, positive laboratory evidence of tuberculosis, radiological evidence of active or healed TB, and ≥3 months follow-up were included. Each case was matched with three controls without dual margins. All patients received oral corticosteroids (prednisolone 1 mg/kg, tapered over 1-2 months) with concurrent antitubercular therapy. Primary outcomes were paradoxical worsening (PW), recurrence, and need for additional immunosuppression. Logistic regression was used to analyze risk factors for PW. Results Three hundred and sixty-six patients of active SLC were screened and twenty-one cases and 63 controls were evaluated. PW occurred significantly more often in the dual-margin group (47.6% vs. 14.3%, p = .002). Recurrence rates were comparable (9% vs. 6%, p = .63). Escalation of immunosuppression, including increased corticosteroid use or additional immunomodulatory therapy, was required more frequently in cases (47.6% vs. 20.6%, p = .01). Conclusion Dual AF margins may serve as an imaging biomarker of aggressive TB SLC and may predict higher risk of PW and greater immunosuppressive requirements. Early recognition may facilitate closer follow-up and timely therapeutic escalation.