Microbial Etiology and Predisposing Factors Among Patients Hospitalized for Corneal Ulceration

Objective: To report the spectrum of microorganisms causing corneal ulceration in patients treated on an inpatient basis and to characterize the predisposing factors.

Design: Case series.

Setting: Large university-affiliated hospital in Toronto.

Patients: All inpatients with corneal ulcers managed between February 1991 and February 1993 (n = 95).

Results: Coagulase-negative staphylococci (30% of the 60 culture-positive cases), Staphylococcus aureus (23%), Streptococcus pneumoniae (12%), Pseudomonas aeruginosa (12%) and Moraxella (7%) were the predominant isolates. Previous eye surgery (cataract extraction in 30 cases [32%], penetrating keratoplasty in 12 [13%] and both procedures in 9 [9%]) was a common predisposing factor. Eleven cases (12%) were associated with the use of contact lenses, in all cases extended-wear soft contact lenses; six patients wore bandage lenses and five wore contact lenses for cosmetic reasons. Pseudomonas was the predominant isolate among contact lens wearers (four cases). Most of the 95 cases involved older patients (average age 62.5 years) with concomitant eye or systemic disease. Sixteen patients (17%) ultimately required penetrating keratoplasty.

Conclusions: Recognition of the risk factors for corneal ulceration and prompt, intensive therapy are important to decrease the morbidity associated with this potentially blinding disease.