br Ocular surface squamous neoplasia OSSN has emerged as

Ocular surface squamous neoplasia (OSSN) has emerged as an important manifestation of the HIV epidemic, especially in sub-Saharan Africa. This region has not only gained the unenviable position of having the highest prevalence of OSSN, but patients with HIV tend to present with larger tumours and have a poorer prognosis. The many factors that may contribute to these important features, such as co-existing human papillomavirus infection, immunosuppression, delayed access to care, and ultraviolet pituitary adenylate cyclase-activating peptide exposure, may also influence the response to therapy. The care providers who are tasked with making evidence-based treatment decisions must often apply the results of studies performed in dissimilar populations, then filter the therapeutic options through the narrow sieve of what is locally feasible. A previous Cochrane review found a paucity of level I or II evidence for the treatment of OSSN in patients with HIV. In , Gichuhi and colleagues provide helpful information to guide the care of individual patients with OSSN, as well as informing those who may influence allocation of resources and future research. Their study fills an important knowledge gap. A readily available topical ophthalmic medication, 5-fluorouracil, was found to decrease the risk of recurrence after excision from 36·2% to 10·6% when compared to placebo. At first glance, the specific regimen may be questioned: why was cryotherapy not employed? Why study 5-fluorouracil when other topical agents, such as interferon alfa-2b and mitomycin-C, are more widely used among corneal specialists in developed nations? The answers to these questions highlight the importance of this study and others in delineating the best practices for OSSN in sub-Saharan Africa and beyond. Recurrence of disease after surgical excision has been described in many regions; however, care must be taken when extrapolating the literature from North American, European, and Australian populations. While the risk factors for recurrence have been reasonably well defined in those typically older, male, white patients, our understanding of OSSN in the frequently younger, HIV-positive patient from Africa is incomplete. At first glance, the recurrence reported in Gichuhi and colleagues study appears higher than in other series; what factors contribute to this finding remain to be determined. The disease itself may carry an intrinsically higher risk of recurrence in this population, and the limited availability of cryotherapy to the excision margins may contribute as well. Gichuhi and colleagues point out that cryotherapy is not readily available in the region. However, even in developed countries, there are few prospective, randomised trials comparing the evolving combinations of surgical techniques and adjuvant chemotherapeutic agents. The ideal approach to OSSN has not yet been defined in any population, and the wide range of reported outcomes mandates that randomised controlled trials are necessary to effectively answer these questions. However, the available evidence supports the efficacy of cryotherapy in reducing recurrence after surgical excision. Opportunities for research and programme development include evaluating the cost-effectiveness of cryotherapy compared to other adjuvants, such as 5-fluorouracil. Adjuvant chemotherapy, either at the time of surgery or postoperatively, has generally been found to decrease the risk of recurrence. Interferon alfa-2b, mitomycin-C, and 5-fluorouracil have all been reported as efficacious. Interferon has gained popularity, both as an empirical monotherapy, and as an additional therapy after surgical excision. However, several characteristics of this medication limit its usefulness in sub-Saharan Africa. Cost is a paramount barrier; although the cost of interferon medical therapy was found to be comparable to surgery in one comparison, that study was based on Medicare-allowable charges for surgery and medication in the USA, which may not be directly applicable to developing regions. It is also important to recognise that interferon is a protein that must be kept refrigerated to remain stable. This likely limits its usefulness in developing countries. Mitomycin would then seem to be a rational alternative; while adrenocorticotropic hormone (ACTH) has been surpassed in popularity by interferon, there are a multitude of studies supporting the efficacy of this agent as monotherapy, or in addition to surgical excision. However, storage at room temperature is not recommended. 5-fluorouracil solution appears to remain stable without refrigeration, and its general availability is encouraged by its place on the World Health Organization\'s list of essential medicines.