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

Abstract 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=0.01. 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 versus IFN - mean 5.5 months, SD 2.9, p = 0.17). Of the 52 eyes whose OSSN resolved with 5FU, 11.5 % of lesions (n=6) recurred while of the 39 eyes whose OSSN resolved with IFN, 5.1% of lesions (n = 2) recurred, p=0.46. 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=0.04) and tearing (p=0.02) 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.