EPIDEMIOLOGY AND ETIOLOGIC DIAGNOSIS OF CORNEAL ULCERATION IN MADURAI, SOUTH-INDIA

Aims/background-To determine the epidemiological characteristics and r isk factors predisposing to corneal ulceration in Madurai, south India , and to identify the specific pathogenic organisms responsible for in fection. Methods-All patients with suspected infectious central cornea l ulceration presenting to the ocular microbiology and cornea service at Aravind Eye Hospital, Madurai, from 1 January to 31 March 1994 were evaluated. Sociodemographic data and information pertaining to risk f actors were recorded, all patients were examined, and corneal cultures and scrapings were performed. Results-In the 3 month period 434 patie nts with central corneal ulceration were evaluated. A history of previ ous corneal injury was present in 284 patients (65.4%). Cornea culture s were positive in 297 patients (68.4%). Of those individuals with pos itive cultures 140 (47.1%) had pure bacterial infections, 139 (46.8%) had pure fungal infections, 15 (5.1%) had mixed bacteria and fungi, an d three (1.0%) grew pure cultures of Acanthamoeba. The most common bac terial pathogen isolated was Streptococcus pneumoniae, representing 44 .3% of all positive bacterial cultures, followed by Pseudomonas spp (1 4.4%). The most common fungal pathogen isolated was Fusarium spp, repr esenting 47.1% of all positive fungal cultures, followed by Aspergillu s spp (16.1%). Conclusions-Central corneal ulceration is a common prob lem in south India and most often occurs after a superficial corneal i njury with organic material. Bacterial and fungal infections occur in equal numbers with Streptococcus pneumoniae accounting for the majorit y of bacterial ulcers and Fusarium spp responsible for most of the fun gal infections. These findings have important public health implicatio ns for the treatment and prevention of corneal ulceration in the devel oping world.