Microbiological study of resistant corneal ulcers

ABSTRACT

Nineteen cases [26 eyes] of resistant corneal ulcers were studied. They were all examined ophthalmologically, generally and microbiologically. The onset of corneal ulceration was variable [2 months to one year] but more than half of the cases were less than one year in duration. Recurrent ulcers were more requent [57.7%]. Central ulcers were the commonest [0.8%] followed by Para central ulcers [15.4%] while peripheral ulcers were the least frequent [3.8%]. 53.8% of ulcers were 3-5 mm in sioze, 30.8% were 1-2 mm and 15.4% were extensive. Rounded ulcers were found in 42.4%, dendritic in 15.4%, amoeboid or oval in 11.5 each, multiple linear or lattice in 7.7% each and creascentic in 3.8%. Deep ulcers with elevated edges were more frequent [57.7%] than the superficial ones. Herpes simplex virus was the commonest agent [61.5%]. Pathogenic bacteria came next [34.6%] while pathogenic fungi had the least role [11.5%]. Infection with one pathogen constituted 73.1% [viral in 57.8%, bacterial in 11.5% and fungal in 3.8%]. Combined infection was less frequent [26.9% viral and bacterial in 19.2% while bacterial and fungal in 7.7%. However, 15.4% of eyes were negative for all organisms. 84.6% of eyes presented with the usual ulcer of the causative organisms. In the remaining 15.4% the picture does not match with the isolated pathogen. Generally, diabetes mellitus was the most frequent condition [15.4%] followed by bilharzias is, addiction and repeated not well-spaced pregnancies in 7.7% each, while typhoid fever and hepatic failure were the least frequent [3.8%]