Purpose  To determine the predisposing factors, demographic characteristics, and etiology of ulcerative keratitis at the Affiliated Hospital of Medical College, Qingdao University.

Methods  A prospective hospital-based study was carried out on 348 consecutive patients presenting with corneal ulcers to the outpatient department of Ophthalmology, Affiliated Hospital of Medical College, Qingdao University, from January 2004 to December 2010. The medical records of admitted patients with positive-culture ulcerative keratitis were retrospectively reviewed for sociodemographic data, predisposing risk factors, clinical details, prior treatment modalities, and microbial culture results. Predisposing factors were compared between bacterial and fungal keratitis.

Results  From January 2004 to December 2010, positive-culture ulcerative keratitis cases was established in 128 (36.8%) out of the total study group of 348 cases. Males (68.6%) were more commonly affected by ulcerative keratitis than females (31.4%). Middle adults 31-60 years of age were the most common age group to be involved (58.3%). Predisposing risk factors were noted in 79% cases. Compared with bacterial keratitis, fungal keratitis was more likely to be associated with ocular trauma (odds ratio = 10.80; 95% confidence interval, 3.33-31.12) but less likely to be associated with contact lens wear (odds ratio = 0.03; 95% confidence interval, 0.04-0.07). The most frequent microbiological diagnosis was bacterial keratitis (68 eyes, 53.1%), followed by fungal (57 eyes, 44.5%) and Acanthamoeba keratitis (3 eyes, 2.3%). The most common organisms isolated were Pseudomonas aeruginosa for bacteria and Fusarium solani for fungus.

Conclusions  In our study, Genus Staphylococcus and Fusarium are the most isolated pathogen of bacterial and fungal keratitis, with Pseudomonas aeruginosa and Fusarium solani being the most common species respectively. Fungal keratitis was more likely than bacterial keratitis to be associated with ocular trauma, whereas fungal keratitis was less likely to be associated with contact lens wear.