Microbial keratitis in the elderly: a 32-year review.

PURPOSE To describe the demographic characteristics, associated factors and causative agents of infectious keratitis in the elderly in a tertiary referral center in São Paulo, Brazil. METHODS A retrospective review of all patients aged 60 years and over with a presumptive diagnosis of infectious keratitis who had material collected for microbiological analysis, between the years 1975 and 2007 (32-year span). RESULTS From a total of 7,060 age-independent cases of microbial keratitis, 1,545 cases in the elderly were reviewed, which had a mean age of 71.0 ± 7.8 years, ranging from 60 to 101 years. There were 707 males (45.6%) and 838 females (54.3%). Associated factors were: past ocular surgery (25.1%), ocular trauma (7.2%) and contact lens use (3.0%). Bacterioscopy was positive in 40.5% of cases. Culture positivity for any agent was 53.5% (bacteria 47.0%, fungi 6.1%, Acanthamoeba 0.4%). The most frequent bacteria were the gram-positive cocci (mostly coagulase-negative Staphylococci) and gram-negative bacilli (mostly the genera Pseudomonas, Moraxella and Proteus), while the most frequent fungi were the filamentous (mostly the genus Fusarium). CONCLUSIONS This study represents a large series of microbial keratitis in the elderly in a single referral center. The most important factor associated with this condition in the elderly was past ocular surgery. The most frequent causative agents were bacteria, especially gram-positive cocci and gram-negative bacilli.