Analysis of the Risk Factors Predisposing to Fungal, Bacterial & Acanthamoeba Keratitis in South India (Report‪)‬

Corneal diseases, especially infective keratitis, are a major cause of vision loss and blindness second only to cataract (1). A study from south India reported that the incidence of corneal infections in India is almost 10 times that reported in the United States (2). This is likely to be the case in other developing countries as well (3-5). Infective keratitis may be caused by bacteria, fungi, protozoa and virus, and the spectrum of microbial pathogens causing keratitis varies according to the geographical locations and climate (6-9). Infective keratitis rarely occur in normal eyes without any predisposing factors. The ocular surface is normally protected from microbial invasion through an intricate biochemical and anatomic relationship between the cornea, conjunctiva, lacrimal secretory apparatus and precorneal tear film, and the eye lids. Any disruption of the same may results in less effective defense against infection and such risk factors may vary with occupation. An association has been shown between the type of risk factor and the microbial aetiology for infection (10). Corneal injury due to vegetative matter predispose mainly to fungal keratitis (8), while use of contact lenses and other nontraumatic risk factors to bacterial keratitis (11,12). Thus, the analysis of such associated risk factors and the isolated microbial aetiology will help in understanding the relationship between risk factors and microbial keratitis, and is essential for initiation of empirical antimicrobial therapy with subjective interpretation of presenting clinical features for practicing ophthalmologist. The purpose of this study was to identify the specific risk factor predisposing to infective keratitis (non viral) and an attempt was also made to determine the association between the risk factors identified and the microbial aetiology of the infective keratitis (non viral) in south India.