for OSSN following excision range between 15%–52% (Lee and Hirst 1995). Incomplete excision with positive surgi- cal margins has been identiﬁed as a major risk factor for recurrence. Erie and colleagues (1986) showed that excised lesions with negative surgical margins had a recurrence rate of 5%, whereas the recurrence rate in those lesions that were incompletely excised increased to 53%. Similarly, Pizzarello and Jakobiec (1978) found that if dysplastic tissues were left at the surgical margin, there was a 69% recurrence rate. The more severe grades of OSSN also appear to recur at higher rates; CIN lesions have a recurrence rate of 17%–24% whereas squamous cell carcinoma recurs in 30%–41% of cases following surgical excision (Erie et al 1986). When adjunctive cryotherapy is used with surgical excision, recur- rence rates appear to be reduced, ranging between 7%–22% (Divine and Anderson 1983; Dutton et al 1984; Peksayar et al 1989). Cryotherapy is thought to act through its direct destructive effects on cells as well as the obliteration of the microcirculation in the areas treated, resulting in ischemic infarction of abnormal tissues. Other treatment modali- ties used for OSSN include beta-radiation therapy (Elkon and Constable 1979; Jones et al 1991), gamma radiation (Goldberg et al 1963), immunotherapy with dinitrochloro- benzene (DNCB) (Ferry et al 1976), and the excimer laser for corneal disease (Dausch et al 1994). When considering aggressive treatment options such as enucleation or even exenteration, it should be kept in mind that ocular invasion and systemic metastasis are uncommon occurrences with OSSN (Lee and Hirst 1995). Over the past ten years, there has been a paradigm shift in the treatment approach of OSSN. Topical agents are now commonly employed for a wide spectrum of OSSN lesions, being used by clinicians as both adjunctive and primary therapy (Frucht-Pery et al 1997; Stone et al 2005). Through the work of various investigators, topical MMC has been established as an effective primary treatment option for OSSN lesions. Rozenman and Frucht-Pery (2000) published a case series of 8 patients who had small, superﬁcial OSSN lesions ( 8 mm in diameter) treated with topical MMC as primary therapy. In all eight patients, the size of the CIN started to decrease with one course of therapy with 0.02% MMC given for 14 days, although in ﬁve cases, a second course of MMC was required to eradicate the lesions. There were also two treatment failures; one case required an excisional biopsy for persistent disease after two courses of MMC, and another patient developed a clinical recurrence 11 months later that was treated successfully with a third course of MMC. This paper was illustrative in that even with Clinical Ophthalmology 2008:2(3) Topical treatment options for conjunctival neoplasms small, superﬁcial OSSN lesions, repeated courses of topical MMC were required to achieve tumor regression. Further- more, the regrowth of CIN occurred within the ﬁrst year of treatment with MMC, indicating that some neoplastic cells survived courses of topical therapy despite the observation of “complete” clinical regression. Wilson and colleagues (1997) reported a case series of 7 patients with diffuse CIN who were considered poor surgical candidates or those who had experienced recurrences despite prior surgical treatment. Three patients had moderate to severe dysplasia and four patients had carcinoma in situ. In this protocol, patients used topical MMC 0.04% for 7 day cycles which were repeated until tumor control was achieved. With this regimen, six of the seven eyes had a complete clinical regression with a maximum of 21 days of therapy, with one patient requiring surgical excision and adjunctive cryotherapy for a partial response. Topical MMC appeared to be effective in this group of patients with more resistant CIN lesions, although a stronger concentration of 0.04% MMC was employed. Prabhasawat and colleagues (2005) used a lower dose of MMC (0.02%), similar to the regimen used by Rozenman, to treat a group of patients with recurrent or extensive OSSN. The patients in this study used 0.02% MMC continuously 4 times daily until the tumor completely regressed, as observed clinically and proven by impression cytology. This regi- men was successful in six of the seven cases, for a success rate of 85.2%. The tumor elimination time ranged between 2–18 weeks and the mean duration of MMC treatment was 5.4 weeks (range, 2–14 weeks). The authors noted that the lower dosage allowed patients to tolerate the therapy for a longer duration than had been reported in the Wilson series, although the total time to tumor elimination was similar to the higher dose interval treatment (Heigle et al 1997; Wilson et al 1997). Several authors have used topical MMC as a surgical adjunct for OSSN lesions, both preoperatively to decrease the size of diffuse lesions before surgical excision and postoperatively to decrease recurrences (Akpek et al 1999; Frucht-Pery et al 2002; Kemp et al 2002; Chen et al 2004; Shields et al 2005). Shields and colleagues reported their experience using MMC as a neoadjuvant chemotherapy agent for tumor reduction (chemoreduction) prior to the surgical resection of thick, extensive conjunctival SCC (Shields et al 2005). Their protocol involved repeating 7 day treatment cycles until no further regression was evident or the patient became intolerant of the toxic effects of the medication. Surgery was performed at least 2 weeks or more following discontinuation of MMC to allow for recovery of 509