The Global Incidence of Fungal Keratitis

Abstract

Background: Fungal keratitis is a severe corneal infection which often results in blindness and eye loss. The disease is most prevalent in tropical and subtropical climates, and sufferers are largely young agricultural workers of low socioeconomic status. Early diagnosis and treatment may preserve vision. We estimated the global burden of fungal keratitis. Methods: A complete systematic review of the literature from 1946 to 2018 was performed using Embase, Medline, PubMed, CINAHL and Cochrane. Our searches identified 3,668 records, of which 182 papers were obtained from 50 countries for detailed analysis. An adapted GRADE score was used to evaluate papers. Findings: 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 1,052,815 cases (range 736,971-1,368,660), with the highest rates in Asia and Africa. If all culture negative cases are assumed to be fungal, the annual incidence would be 1,482,364 cases (range 1,037,655 to 1,927,073). In 3 series, 8-11% of patients had to have the eye removed, an annual loss of an estimated 94,753 to 115,810 eyes. Interpretation: Fungal keratitis likely affects over a million people annually. An inexpensive simple diagnostic method and global availability of affordable treatment are needed. Funding: No external funding. MJB is supported by The Wellcome Trust (207472/Z/17/Z). Declaration of Interest: The authors declare no conflict of interest.