Introduction

Microbial keratitis is a potentially serious corneal infection and a major cause of visual impairment worldwide. A conservative estimate of the number of corneal ulcers occurring annually in the developing world alone is 1.5–2 million.1 Permanent visual dysfunction has been reported in a significant proportion of patients in both developing2 and developed3 countries. Srinivasan et al4 comment that ulceration of the cornea in south India ‘is a blinding disease of epidemic proportions.’

Various micro-organisms can cause microbial keratitis, and predisposing risk factors vary from one geographic region to another. They include pre-existing corneal disease as well as other risk factors such as contact-lens wear, surgical or non-surgical trauma, and ocular surface disease. …