One-Hour Versus 3-Day Regimen of Topical Gatifloxacin 0 One-Hour Versus 3-Day Regimen of Topical Gatifloxacin 0.3% to Reduce the Conjunctival Flora Ana Lilia Pérez - Balbuena MD Virginia Vanzzini Zago QFB. Lorena López Quezada MD. Antonio Sierra- Acevedo MD Authors have no financial interest in the subject matter of this poster.

Introduction In surgical ophthalmology, prophylaxis is indicated in all cases with high risk of infection. Antimicrobial prophylaxis is widely accepted and used around the world in patients undergoing cataract surgery, implants, grafts or intraocular lenses. International studies shows that gatifloxacin 0.3% , a fourth generation fluoroquinolone have demonstrated excellent results eradicating bacterial flora of the conjunctival sac, in previous and postoperative surgical procedures in the ophthalmology field. There is no consensus on the dosing schedule with prophylactic purposes, neither internationally nor in the Mexican population. The research group of Association to Avoid Blindness in Mexico, “Asociación para Evitar la Ceguera, Hospital Luis Sánchez Bulnes IAP (APEC)” has designed and developed a clinical trial comparing the effects of 1 drop of gatifloxacin 0.3% every 15 minutes (4 doses one hour) versus of 1 drop every 4 hours during 3 days before surgery.

Study design Purpose. Evaluate the efficacy of gatifloxacin 0.3% to reduce the CFU (colony forming units) in the conjunctival sac. Design. Open, prospective, longitudinal, comparative and experimental study. Sample size. 60 patients (120 eyes) divided in 2 groups of 30 patients (1 & 2). Group 1. Patients receiving 1 drop (10 μl) of gatifloxacin 0.3%, subject-to-surgery eye, every 15 minutes (4 times), 1 hour before surgical cataract or lasik. Group 2. Patients receiving 1 drop (10 μl) of gatifloxacin 0.3%, subject-to-surgery eye, every 4 hours during 3 days before surgical cataract or lasik.

Alginate swabs before and after phosphate buffer (2 ml) disolution. Materials and methods. One tear sample from the ocular surface from both eyes of the 60 patients obtained before and after applying gatifloxacin 0.3% in order to identify the changes in bacterial flora before surgery. Statistic analysis. For independent samples, mean difference; for decrement, one tale t test. Hypothesis. Gatifloxacin 0.3% is effective to reduce CFU (colony forming units) in the conjunctival sac. Culture buth eyes solution Alginate swabs before and after phosphate buffer (2 ml) disolution. Case N° 54

Demographics 1…. The protocol tests two similar populations to evaluate the statistical likelihood of the hypothesis 1st group 2nd group 30 patients, 60 eyes 30 patients, 60 eyes 16 males, 14 females 10 males, 20 females 47.5 average age, 19.6 standard deviation 34.3 average age, 15.9 standard deviation Half eyes (without treatment, control) & Half eyes (under treatment, study) Half eyes (without treatment, control) & Half eyes (under treatment, study)

Demographics 2…. The drop in CFU analysis tested the presence of multiple bacteria often encountered in cataract or lasik surgery patients Total CFU’s basal average: 21.2 Total CFU’s basal average: 38.52 *Other bacteria considered: Acetinectobacter Iwoffi, Neisseria flava, Pseudomonas maltofilia, Moraxella, Bacillus subtilis, Klebsiella ozaenae, Flavimonas spp

Efficacy 1 hour…. The study shows that gatifloxacin 0.3% is effective in the reduction of pathogens after one hour of treatment Percentage % of eyes with 50% or more bacteria reduction 82.14% % bacteria eradicated 46.42% Percentage % of eyes with 50% or more bacteria reduction 52.63% % bacteria eradicated 26.31% Gatifloxacin 0.3% reduces more bacteria present than no treatment (P = 0.004)

Efficacy 3 days…. The study shows that gatifloxacin 0.3% is effective in the reduction of pathogens after three days of treatment Percentage % of eyes with 50% or more bacteria reduction 83.33% % bacteria eradicated 66.66% Percentage % of eyes with 50% or more bacteria reduction 75.00% % bacteria eradicated 70.00% Gatifloxacin 0.3% reduces more bacteria present than no treatment (P = 0.09)

Reduction per bacteria type… Gatifloxacin 0.3% was effective in the reduction of bacteria of the 30 eyes under treatment 82.14% of the sample under treatment diminished more than 50% bacteria in an hour period vs. 52.6 % without treatment 83.33% of the sample under treatment diminished more than 50% bacteria in the 3 days period vs. 75% without treatment The % of the total CFU dropped from 21.2 to 3.83 The % of the total CFU dropped from 38.52 to 0.97 (P = 0.014)

Conclusion The Mexican population study confirms that gatifloxacin 0.3% (Zymar©) is effective in the reduction of bacteria in the conjunctival sac. After one hour of treatment the percentage of total CFU dropped from 21.2 to 3.83. After three days of treatment the percentage of the total CFUs diminished from 38.52 to 0.97. Some bacteria type responded better with a short period of treatment like: Staphylococcus epidermidis Corynebacterium spp Staphylococcus aureus In urgent procedures the apply of 1 hour of treatment is as effective as longer treatment schedules.

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