Effect of Topical Fluoroquinolones on Epithelial Wound Healing After PRK

Overview

The prescribed antibiotic for prophylaxis of infection following PRK should be effective at eradicating a potential infection. In addition, the antibiotic should have a rapid onset of action, effectively penetrate the target tissue, and be safe and not toxic to any layer of the healing cornea, especially the epithelium. Several studies have investigated the toxicity of the fourth generation fluoroquinolones on the corneal epithelium and studies have demonstrated that gatifloxacin is less deleterious to the healing cornea than moxifloxacin. Most of these studies, however, have been conducted in animals. This was a retrospective chart review.

Prior generation fluoroquinolones predominantly either inhibit topoisomerase II (DNA Gyrase) or topoisomerase IV and therefore only require one genetic mutation for bacteria to develop resistance. Fourth-generation fluoroquinolones are equally effective against topoisomerase II and IV, which significantly expands their spectrum of action against gram-positive agents and atypical mycobacteria and Nocardia . This duality of action of the fourth generation fluoroquinolones requires that for bacteria to become resistant to these agents, the bacteria must undergo two genetic mutations resulting in a significantly decreased chance of an organism developing resistance.Minimum inhibitory concentrations determined in vitro suggest that fourth-generation fluoroquinolones are more effective than second- and third-generation fluoroquinolones against gram-positive bacteria including Staphylococcal species found in endophthalmitis and bacterial keratitis cultures. The increased efficacy of fourth-generation fluoroquinolones make these antibiotics important agents to evaluate for prophylaxis against post-PRK infections. This was a retrospective chart review.

Conditions