To investigate the epidemiological, microbiological, and clinical characteristics of inpatients with infectious keratitis and also to elucidate risk factors for unimproved visual outcomes.

We performed a retrospective chart review of 167 eyes in 167 patients with infectious keratitis hospitalized between January 2005 and December 2007 at Yeungnam University Hospital.

Keratitis cases were classified into four groups according to etiology: 92 bacterial, 43 herpes virus, 31 fungal, and 1 acanthamoeba. Culture positivity was 44.6% in bacterial keratitis and 22.6% in fungal keratitis, and KOH positivity of fungus was 48.4%. Of all the 55 isolated pathogens, the most commonly isolated microorganisms were S. epidermidis in Gram-positive bacteria, P. aeruginosa in Gram-negative bacteria, and Candida species in fungus. Epidemiologic characteristics such as male gender (59.9%), an age in the seventh decade (24.6%), farming occupation (40.1%), and trauma with vegetable matter (42.5%) were noted. Many fungal and bacterial keratitis cases were characterized by inadequate use of topical steroid when patients initially presented to our clinic. Visual outcomes were poorer in fungal keratitis than they were in other forms of keratitis.

Risk factors for unimproved visual outcomes included an ulcer exceeding 3 mm in size and a fungal source. Therefore, a strong effort should be made to discern a differential diagnosis in infectious keratitis and to determine the appropriate early treatment for a successful treatment outcome.