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Published on: May 12, 2020
Trends in microbial keratitis in Japan
Hiroshi Toshida1, Nobuyuki Kogure, Naoki Inoue
1Department of Ophthalmology, Juntendo University School of Medicine, Tokyo, Japan. toshida@med.juntendo.ac.jp
Purpose:
To identify microbiologic characteristics of infectious keratitis and predisposing factors.
Methods:
The microorganisms isolated from patients with infectious corneal ulcers during the 5 years between January 1999 and December 2003 were retrospectively examined. Herpetic and other viral infections were excluded from this study. Patient age, sex, risk factors, and isolated organisms were collected.
Results:
In 123 eyes of 122 patients, organisms were isolated from 72 (58.5%) eyes. In total, 99 different organisms were isolated. Among these, 77 (77.8%) were gram-positive bacteria; 18 (18.2%) were gram-negative bacteria; six (6.1%) were fungi; and one (1.0%) was acanthamoeba. Contact lens wear was the main risk factor (54.5%), and ocular surface disease and previous ocular surgery were present in 20.5% and 13.1% of cases, respectively. Posttreatment visual acuity was significantly improved by pretreatment in culture-positive groups treated according to the antibiotic susceptibilities (Wilcoxon t test, P<0.01).
Conclusions:
The results are changing to those reported by other countries and generations. Contact lens wear is the most important risk factor in Japan. The results of isolation and culture are essential for improving the cure rate.
Insights
Infectious keratitis is often caused by bacteria, with contact lens wear being the primary risk factor. Identifying causative organisms through cultures is crucial for effective treatment and improved visual outcomes.
Area of Science:
- Ophthalmology
- Microbiology
- Infectious Diseases
Background:
- Infectious keratitis is a significant cause of corneal blindness worldwide.
- Understanding the specific microbial profile and risk factors is essential for effective management.
Purpose of the Study:
- To determine the microbiological characteristics of infectious keratitis.
- To identify predisposing factors associated with infectious keratitis.
Main Methods:
- Retrospective analysis of microorganisms isolated from infectious corneal ulcers between 1999 and 2003.
- Exclusion of herpetic and other viral infections.
- Collection of patient demographics, risk factors, and isolated organisms.
Main Results:
- Organisms were isolated from 58.5% of 123 eyes; 99 organisms were identified.
- Gram-positive bacteria (77.8%) were the most common pathogens, followed by gram-negative bacteria (18.2%), fungi (6.1%), and Acanthamoeba (1.0%).
- Contact lens wear (54.5%) was the leading risk factor, followed by ocular surface disease (20.5%) and prior ocular surgery (13.1%).
Conclusions:
- Microbial patterns are evolving and differ internationally.
- Contact lens wear is the predominant risk factor for infectious keratitis in Japan.
- Microbial identification via culture and susceptibility testing is vital for enhancing treatment success rates and visual acuity.
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