This prospective, nonrandomized clinical study assessed the demographics and outcomes of infectious keratitis in Asia.
Study design
During the 18-month study period, researchers recruited 6,563 patients (6,626 eyes) with infections keratitis from 11 study centers in 8 countries (India, China, Japan, South Korea, Taiwan, Thailand, Philippines and Singapore). Only 1% of patients exhibited bilateral infection at time of presentation.
Patients were observed for 6 months. Samples were collected by corneal scrapings or corneal biopsies and examined for antimicrobial resistance profiles. Standardized report forms were used to document clinical and demographic features along with risk factors and treatment modalities.
Outcomes
Trauma was identified as the most common risk factor (34.7%) followed by contact lenses wear (10.7%), prior surgery (6.8%) and ocular surface disease (4.2%). Overall, 38.0% of eyes had bacterial keratitis and 32.7% had fungal keratitis. While most eyes were only medically treated (55.0%), 14.5% of eyes required surgical treatment. The majority of eyes (53.6%) exhibited moderate visual impairment.
A total of 2,831 unique microorganisms were isolated. Those isolated in China and India were most often fungal; bacterial microorganisms were more common in the remaining countries.
Limitations
The preponderance of cases from India (56.1%) skewed some data, such as the large proportion of fungal infections and identification of trauma as a leading cause. Compared with community settings, the focus on study centers with advanced laboratory diagnostics likely resulted in more severe presentations and caused some countries to be underrepresented.
Clinical significance
This large clinical study helps further elucidate the nature and outcomes of infectious keratitis in Asia. The study outlines key risk factors that may be targeted to reduce the incidence of infectious keratitis in the future.