Comparison of Topical 5-Fluorouracil and Interferon Alfa-2b as Primary Treatment Modalities for Ocular Surface Squamous Neoplasia

Purpose: To compare the efficacy of topical 5-fluorouracil 1% (5FU) and interferon alfa-2b 1 MIU/mL (IFN) eye drops as primary treatment modalities for ocular surface squamous neoplasia (OSSN). Design: Retrospective, comparative, interventional case series. Methods: Fifty-four patients who received 5FU and 48 patients who received IFN as primary therapy for OSSN were included. Primary outcome measures were the frequency of clinical resolution and time to OSSN recurrence by treatment modality. Secondary outcome was the frequency of side effects with each therapy. Results: The mean age of patients was 68 years. More Hispanics were treated with 5FU. In a univariable analysis, frequency of OSSN resolution was higher with 5FU (96.3%, n = 52) than with IFN (81.3%, n = 39), P =.01. In a multivariable analysis, treatment modality did not remain a significant predictor of resolution. In patients whose OSSN resolved, time to resolution was similar with both agents, (5FU mean 6.6 months, standard deviation (SD) 4.5 vs IFN mean 5.5 months, SD 2.9, P =.17). Of the 52 eyes whose OSSN resolved with 5FU, 11.5% of lesions (n = 6) recurred, whereas of the 39 eyes whose OSSN resolved with IFN, 5.1% of lesions (n = 2) recurred, P =.46. Kaplan-Meier survival curves of OSSN recurrence were similar between groups (log-rank = 0.16). One-year recurrence rates were 11.4% with 5FU and 4.5% with IFN. Eyelid edema (P =.04) and tearing (P =.02) were more significant with 5FU. Conclusions: This is the first direct comparison study between 5FU and IFN eye drops as primary treatment modalities for OSSN. Both modalities resulted in a high frequency of tumor resolution and low recurrence rates and are effective treatment options for OSSN.