Topical 5-fluorouracil 1% versus surgical removal as a primary treatment modality for ocular surface squamous neoplasia: a comparison of recurrences and side effects.

PURPOSE: To compare the efficacy and safety of topical 5-fluorouracil (5-FU) 1% eye drops versus surgical removal as a primary treatment modality for ocular surface squamous neoplasia (OSSN). METHODS: This retrospective cohort study included 11 patients who received 5-FU 1% (5-FU group) and 14 patients who received surgical removal (surgery group) as a primary therapy for OSSN in an ophthalmic hospital from 2018 to 2023. The primary outcome measure was the comparative incidence of OSSN recurrence between the two therapeutic modalities. The secondary outcome was the frequency of side effects with each therapy. RESULTS: No significant differences were found in demographic characteristics, with comparable mean ages (5-FU group: 58.6 ± 22.7 vs. surgery group: 63.1 ± 14.4 years, p = 0.55) and gender distributions (male: 81.8% vs. 78.6%, p = 1.00). The recurrence rate was 18.2% in the 5-FU group versus 14.3% in the surgery group (p > 0.99). There was no statistically significant difference in the recurrence rate between the 5-FU and surgery groups. Patients were treated a median of 3 cycles (range 1-9) of topical 5-FU eye drops in the 5-FU group. Treatment-related ocular symptoms were reported in 45.5% (5/11) of patients in the 5-FU group, while a 57.1% (8/14) incidence of side effects in the surgical group. The mean follow-up duration for the 5-FU group was 28.4 ± 14.8 months, while that for the surgery group was 36.4 ± 20.3 months. The side effects of the two groups of patients were similar, mainly including redness, irritation, pain, and so on. Limbal stem cell deficiency, symblepharon, and systemic symptoms were not observed in either the 5-FU or surgery groups. CONCLUSIONS: Both 5-FU and surgical removal are effective and present a good security profile as primary therapies for OSSN. The two treatment modalities have no significant difference in the frequency of side effects or the time interval to recurrence.