ABSTRACT
The spectrum of microbial keratitis is dependent on a complex interplay between a diverse group of microorganisms and the host. A corneal ulcer may be defined as a discontinuation in the normal epithelial surface of the cornea associated with necrosis of the surrounding tissue and is pathologically characterised by oedema and cellular infiltration. Ulceration of the cornea, especially if severe and involving the visual axis or with extreme corneal thinning and impending perforation or if already perforated, is an ophthalmic emergency that needs immediate attention and, if not effectively managed, can lead to sight-threatening complications and in extreme situations irreversible loss of vision. Corneal biopsy : performed in cases where repeated smear examinations and microbial cultures of specimens obtained from standard corneal scraping technique reveal negative results such as deep stromal abscess and fungal ulcer.
