To investigate the difference of the epidemiological, microbiological, and clinical characteristics and risk factors of inpatients with infectious keratitis between an elderly group (group I ≥ 60 years) and a younger group (group II < 60 years).

A retrospective chart review of 255 eyes (male/female: 158/97 eyes, I/II: 116/139 eyes) with infectious keratitis hospitalized at Yeungnam University Hospital between January 2004 and December 2008 was performed.

The proportion of bacterial/fungal/herpes viral keratitis was 42/31/27% in group I and 74/8/17% in group II. The proportion of fungal keratitis in relation to bacterial keratitis was higher in group I, as compared to group II ( p < 0.001). The ratio of Gram-positive/negative bacteria was 43/30% in group I and 48/46% in group II. The proportion of Gram-positive bacteria in relation to Gram-negative bacteria was higher in group I, as compared to group II ( p = 0.025). The most commonly isolated microorganisms were Staphylococcus epidermidis (I/II: 9/10 eyes) among Gram-positive bacteria, Enterobacter species (I: 6 eyes) and Pseudomonas aeruginosa (II: 9 eyes) among Gram-negative bacteria, and Candida species (I: 6 eyes, II: 2 eyes) among fungi. Clinical aspects and treatment outcomes, such as previous ocular surgery (I/II: 23/9%), hypertension (26/7%), diabetes mellitus (17/7%), presentation at our clinic after 1 week (43/16%), initial visual acuity less than 0.1 (54/32%), hypopyon (28/15%), epithelial healing time (16/10 days), corneal perforation (18/5%), operative treatment (23/7%), and final visual acuity less than 0.1 (36/14%) were statistically significantly poorer in group I, as compared to group II. Risk factors for unimproved visual outcomes included fungal keratitis in group I and previous ocular surgery and ocular surface disease in group II.

Considering that clinical aspects and treatment outcomes are poor in elderly inpatients with infectious keratitis, special efforts are necessary for a more accurate differential diagnosis and appropriate early treatment to achieve successful treatment outcomes.