Topical interferon therapy in uveitic macular edema

Abstract

Purpose: To evaluate efficacy of topical interferon alfa-2b (IFN) in the treatment of uveitic macular edema (UME). Methods: This is a prospective, interventional case study of patients with UME. Injection IFN was reconstituted into eye drops and a four times/day (QID) application was prescribed. Central macular thickness (CMT) on optical coherence tomography (OCT) scan was evaluated. Improvement in CMT by ≥50 μm from the baseline was studied in eyes with presenting CMT ≥400 μm. Results: Twenty eyes of 20 patients with UME were studied: anterior uveitis (n = 3), anterior + intermediate uveitis (n = 5), posterior uveitis (n = 3), retinal vasculitis (n = 3), and panuveitis (n = 6). Mean CMT at the presentation was 423.3 μm (range: 270-604 μm), which improved at 1 month (n = 16), 2 months (n = 10), and ≥3 months (n = 11) follow-up, to 415.3 μm (range: 247-579 μm) (P = 0.411), 364.4 μm (range: 258-566 μm) (P = 0.099), 344 μm (range: 258-484 μm) (P = 0.001), respectively. Twelve eyes of 12 patients had presenting CMT ≥400 μm. In these cases, decrease in CMT by ≥50 μm was seen in 4/10, 4/5, and 5/6 eyes at 1 and 2 months and ≥3 months follow-up. Mean follow-up was 4 months (range: 1-17 months). Complete resolution of UME was seen only in three eyes. No ocular or systemic side effects were observed. Conclusion: Topical IFN therapy in QID doses is safe but may have limited role in UME. Long-term therapy may improve its efficacy. Larger studies with dose modification, combination with other drugs, and with homogeneous uveitis population are recommended.