Fourth-generation fluoroquinolones: new topical agents in the war on ocular bacterial infections.

The fourth-generation fluoroquinolones, moxifloxacin and gatifloxacin, were introduced in 2003 promising improved spectrum of activity and delayed development of resistance. Although these topical agents have recently been introduced in commercial form, there is already a growing body of evidence showing excellent potency in the war on ocular infections. The purpose of this review is to discuss the literature to date regarding these two agents. Since their introduction in 1990 in the United States, fluoroquinolones have rapidly become the standard of care in the topical antibiotic arena. Unfortunately, recent evidence has shown the widespread use of fluoroquinolones, not only in eye care, but also in agriculture, and general medical and surgical use, has lead to decreasing susceptibilities of important ocular bacterial pathogens. Moxifloxacin and gatifloxacin have improved potency and are able to overcome resistant isolates. These agents also provide improved penetration into ocular tissues. Moxifloxacin and gatifloxacin offer improved spectrum of activity, increased penetration into ocular tissues, and delayed propensity to the development of bacterial antibiotic resistance.