Microsporidial Stromal Keratitis: A Rare Entity in Central Europe

Abstract

Recent data analyses account for corneal opacities as the fifth leading cause of blindness worldwide [1], with infectious keratitis being the most common condition [2], [3]. Microsporidia are obligate intracellular, spore-forming fungi that may cause such infectious keratitis. Their ubiquitous presence in the environment leads to frequent human exposure [4], although the exact pathogenesis of keratitis remains unclear. Direct inoculation with contaminated water, food, soil, and ocular trauma has been postulated [5], [6]. There are two different corneal manifestations of microsporidial keratitis: multifocal epithelial keratitis, which mainly affects immunosuppressed patients as in human immunodeficiency virus (HIV), and stromal keratitis, largely seen among immunocompetent individuals [7]. The disease entity is endemic in Asian countries and has rarely been reported in Europe [8]. We describe a case of histopathologically confirmed stromal microsporidial keratitis diagnosed at a tertiary care hospital in Switzerland.