Aim To report the outcome of treatment of localised non-invasive ocular surface squamous neoplasia (OSSN) where topical 5-fluorouracil (5-FU 1%) is used as an adjuvant to surgical excision.

Methods The study was a prospective non-comparative interventional case series. 55 cases of primary localised OSSN and 10 cases of recurrent localised OSSN were treated with excision, cryotherapy and adjuvant 5-FU 1%. In all cases, irrespective of the involvement of surgical margins, a single cycle of 5-FU 1% was administered, four times a day for 2 weeks continuously. The main outcome measures were (1) recurrence and (2) complications related to adjuvant topical chemotherapy. Individuals were reviewed for a minimum of 12 months.

Results There was a single case of recurrence (1.5%). 57% of patients had short-term complications secondary to 5-FU 1%, most frequently lid toxicity (49%), followed by superficial keratitis, epiphora and corneal epithelial defects. Four patients were unable to complete the course of 5-FU 1% because of local toxicity.

Conclusions The management of localised non-invasive OSSN with adjuvant 5-FU 1% was associated with a low rate of local recurrence. Although 5-FU 1% frequently results in short-term complications, most commonly lid toxicity, a full course is usually tolerated. Serious complications appear uncommon in the treatment of localised disease.