Clinical utility of caspofungin in ocular fungal infections

Direct exposure of the eye to the environment, along with the impaired host defences due to the breach of anatomical barriers, increases the risk of fungal eye infections in humans. Ocular fungal infections, including keratitis and endophthalmitis, are often sight-threatening and require early diagnosis and appropriate antifungal therapy. Importantly, the range of antifungal agents available for the treatment of fungal eye infections remains limited and can be considered as inadequate. The lack of favourable outcomes with the existing antifungal treatments (e.g. poor ocular penetration after topical or systemic administration, poor drug bioavailability in the cornea, narrow spectrum of antifungal activity, limited clinical success, ocular toxicity) has further complicated the situation. Therefore, an alternative treatment for fungal eye diseases is urgently needed. In recent years, attention has focused on the use of caspofungin, an echinocandin, which is available only as an intravenous injection. This chapter will explore aspects related to the use of caspofungin in fungal eye infections, particularly fungal keratitis or endophthalmitis, including a brief discussion of other alternatives. It will discuss in an in-depth manner, the ocular penetration of caspofungin, its susceptibility, efficacy and safety profile including data related to caspofungin use in patients with fungal keratitis or endophthalmitis, and the stability of the caspofungin eye drops.