Topical 5-fluorouracil 1% for moderate to extensive ocular surface squamous neoplasia in 73 consecutive patients: Primary versus secondary treatment.

Importance: Ocular surface squamous neoplasia (OSSN) is a spectrum of malignancies that generally includes conjunctival intraepithelial neoplasia (CIN) and squamous cell carcinoma (SCC). OSSN can be treated with topical therapies including interferon α-2b (IFN), mitomycin C (MMC), or 5-fluorouracil 1% (5FU). Recently, due to unavailability of IFN and toxicity associated with MMC, therapy has shifted towards 5FU.