Comparison of one-day versus one-hour application of topical gatifloxacin in eliminating conjunctival bacterial flora.
Author(s): Moss JM, Nguyen D, Liu YI, Singh K, Montague A, Egbert PR, Kaspar HM, Ta CN
Affiliation(s): Stanford University Medical Center, Department of Ophthalmology, Stanford, California, USA.
Publication date & source: 2008-11, Ophthalmology., 115(11):2013-6. Epub 2008 Aug 16.
Publication type: Clinical Trial; Comparative Study; Research Support, Non-U.S. Gov't
PURPOSE: To compare efficacies of 1-day, 1-hour, and combined 1-day/1-hour preoperative topical gatifloxacin in eliminating conjunctival bacterial flora. DESIGN: Prospective, comparative case series. PARTICIPANTS: Sixty patients (120 eyes) scheduled to undergo anterior segment intraocular surgery at Stanford University Medical Center. METHODS: Cultures were collected from the palpebral conjunctival sac at baseline and after 1 day (4 doses), 1 hour (3 doses), and 1 day/1 hour (7 doses) of gatifloxacin use. MAIN OUTCOME MEASURES: Incidence of positive bacterial samples collected pre- and post-antibiotic treatment and number of colony forming units (CFUs). RESULTS: SeptiChek (Becton Dickinson, Franklin Lakes, NJ) positive cultures significantly decreased from 67% growth at baseline to 28% (P<0.0001) after 1 day and from 60% at baseline to 37% (P = 0.018) after 1 hour of gatifloxacin use. Reductions of 44% growth at baseline to 12% (P = 0.0001) after 1 day and 32% at baseline to 13% (P = 0.029) after 1 hour of gatifloxacin use were observed on blood agar. Surgical eyes that received both 1-day and 1-hour preoperative gatifloxacin had reductions from 67% growth at baseline to 18% posttreatment (P<0.0001) and 45% at baseline to 7% posttreatment (P<0.0001) on SeptiChek and blood agar media, respectively. In addition to a lower frequency of positive cultures, a significantly lower CFU count was found after 1-day (P = 0.004) and 1-hour (P = 0.049) gatifloxacin use compared with pretreatment levels. Combined 1-day/1-hour doses of gatifloxacin were associated with a greater reduction in CFUs (P = 0.001) when compared with 1-hour treatment alone. CONCLUSIONS: Both 1-hour and 1-day topical gatifloxacin use are effective in reducing the frequency of conjunctival bacterial growth and the overall bacterial load as measured by CFUs, relative to baseline. Although a 1-hour pretreatment is associated with a reduction in bacterial growth, the combination of 1-day and 1-hour preoperative gatifloxacin dosing results in an even lower overall bacterial load, suggesting that the latter might be the preferred preoperative regimen for eyes undergoing anterior segment surgery.
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