ABSTRACT
BACKGROUND: Ocular surface squamous neoplasia (OSSN) characterized by diffuse conjunctival or corneal spread is much less common than localized conjunctival disease. However, it is an important subcategory of the disease because of the difficulty it poses to treatment. It is rarely amenable to simple excision, and a purely surgical approach usually necessitates ocular surface reconstruction. Primary treatment with topical chemotherapy is an alternative, but its efficacy for these lesions is not well understood. DESIGN: Retrospective case series. PARTICIPANTS: Thirty-eight eyes treated for diffuse OSSN, defined as a lesion extending over five or more limbal clock hours or by extensive central or paracentral corneal spread. METHODS: Treatment utilized either topical 5-FU 1% or mitomycin-C (MMC) 0.04%. MAIN OUTCOME MEASURES: (i) Disease remission; (ii) complications. RESULTS: Thirty-two patients were treated for a primary diffuse OSSN. Ten patients (31%) required further treatment for disease persistence or recurrence. Thirteen patients had previously undergone a single unsuccessful treatment course for diffuse OSSN. Administration of a second treatment course (whether MMC or 5FU) was successful in 46% (six) of patients. 5-FU 1% resulted in drug-related complications in seven of 12 cases, and included a single case of focal paracentral corneal stromal melt. MMC 0.04% resulted in transient drug related complications in 23 of 39 cases. CONCLUSION: Diffuse OSSN is often recalcitrant to initial treatment with either 5-FU 1% or MMC 0.04%, and a pragmatic and vigilant approach to this heterogenous disease is required. Compared to localized disease, diffuse disease often requires multiple treatment efforts.