The global incidence and diagnosis of fungal keratitis

Fungal keratitis is a severe corneal infection that often results in blindness and eye loss. The disease is most prevalent in tropical and subtropical climates, and infected individuals are frequently young agricultural workers of low socioeconomic status. Early diagnosis and treatment can preserve vision. Here, we discuss the fungal keratitis diagnostic literature and estimate the global burden through a complete systematic literature review from January, 1946 to July, 2019. An adapted GRADE score was used to evaluate incidence papers—116 studies provided the incidence of fungal keratitis as a proportion of microbial keratitis and 18 provided the incidence in a defined population. We calculated a minimum annual incidence estimate of 1 051 787 cases (736 251–1 367 323), with the highest rates in Asia and Africa. If all culture-negative cases are assumed to be fungal, the annual incidence would be 1 480 916 cases (1 036 641–1 925 191). In three case series, 8–11% of patients had to have the eye removed, which represents an annual loss of 84 143–115 697 eyes. As fungal keratitis probably affects over a million people annually, an inexpensive, simple diagnostic method and affordable treatment are needed in every country.