New treatments for bacterial keratitis.

2012

Wong RL, Gangwani RA, Yu LW, Lai JS.

Source

Eye Institute, The University of Hong Kong, Room 301, Level 3, Block B, 100 Cyberport Road, Cyberport 4, Hong Kong.

Abstract

Purpose. 

To review the newer treatments for bacterial keratitis. 

Data Sources. 

PubMed literature search up to April 2012. Study Selection. Key words used for literature search: "infectious keratitis", "microbial keratitis", "infective keratitis", "new treatments for infectious keratitis", "fourth generation fluoroquinolones", "moxifloxacin", "gatifloxacin", "collagen cross-linking", and "photodynamic therapy". 

Data Extraction. 

Over 2400 articles were retrieved. Large scale studies or publications at more recent dates were selected. 

Data Synthesis. 

Broad spectrum antibiotics have been the main stay of treatment for bacterial keratitis but with the emergence of bacterial resistance; there is a need for newer antimicrobial agents and treatment methods. Fourth-generation fluoroquinolones and corneal collagen cross-linking are amongst the new treatments. In vitro studies and prospective clinical trials have shown that fourth-generation fluoroquinolones are better than the older generation fluoroquinolones and are as potent as combined fortified antibiotics against common pathogens that cause bacterial keratitis. Collagen cross-linking was shown to improve healing of infectious corneal ulcer in treatment-resistant cases or as an adjunct to antibiotics treatment. 

Conclusion. 

Fourth-generation fluoroquinolones are good alternatives to standard treatment of bacterial keratitis using combined fortified topical antibiotics. Collagen cross-linking may be considered in treatment-resistant infectious keratitis or as an adjunct to antibiotics therapy.

PubMed

Trends in Resistance to Ciprofloxacin, Cefazolin, and Gentamicin in the Treatment of Bacterial Keratitis

Trends in Resistance to Ciprofloxacin, Cefazolin, and Gentamicin in the Treatment of Bacterial Keratitis

J Ocul Pharmacol Ther. 2008 Mar 10

Afshari NA, Ma JJ, Duncan SM, Pineda R, Starr CE, Decroos FC, Johnson CS, Adelman RA.
Duke University Eye Center, Duke University Medical Center, Durham, NC.

Purpose: The aim of this study was to evaluate the microbial profile, resistance patterns, and antibiotic sensitivity of bacterial keratitis to three commonly used ocular antibiotics.

Methods: All cases of bacterial keratitis referred to the Massachusetts Eye and Ear Infirmary Microbiology Laboratory from two consecutive annual 10-month periods were reviewed. The bacterial profile and resistance to ciprofloxacin, cefazolin, and gentamicin was evaluated within the two intervals.

Results: Of the 485 cultures analyzed, 66.4% (322) were positive for bacterial isolates. Of these, 19.2% were polymicrobial, 87.5% were gram-positive, and 12.5% were gram-negative. The most prevalent isolate was coagulase-negative Staphylococcus (45.5%), followed by S. aureus (15.2%).

The resistance patterns for gram-positive bacteria for ciprofloxacin for the first versus second time interval were 12% and 22% (P = 0.04) respectively, for cefazolin 13% and 23% (P = 0.04), and for gentamicin 4% and 7% (P = 0.36). The resistance patterns for gram-negative bacteria for ciprofloxacin, cefazolin, and gentamicin were not significantly different in the two tested time periods (all P greater then 0.05).

Conclusions: There was increased resistance of gram-positive organisms to ciprofloxacin and cefazolin, but not gentamicin, in the two examined time periods. Increased resistance to these commonly used antibiotics emphasizes the need for close follow-up after initial empiric treatment, and maintaining a low threshold for selecting alternative therapy.

Liebert