Effect of Perioperative Antibacterial Prophylaxis Using Eye Drops with Fluoroquinolones on Conjunctival Microflora in Patients before and after Phacoemulsification

Abstract

Purpose. to evaluate the efficacy of perioperative antibacterial prophylaxis using eye drops with fluoroquinolones with the evaluation of conjunctival microflora structure with its antibiotic resistance.Patients and Methods. The study was carried out using the results of one preoperative and four times postoperative swabs taken from the conjunctival cavity in 50 patients (52 eyes) aged 49 to 91 undergoing phacoemulsification. All the strains were undergoing the 16 antibacterial drugs-panel susceptibility testing including the most common ophthalmic dosage form in the Russian Federation. The antibacterial drugs instillations were used during the postoperative period: levofloxacin in group 1 (30 eyes) and moxifloxacin in group 2 (22 eyes).Results. The structure of conjunctival microflora in the two groups was similar prior to phacoemulsification. In 32 cases (61.5 %) bacterial growth was obtained preoperatively. Among them S. epidermidis strains were detected in 68.8 %, S. aureus strains were detected in 31.2 %. During the use of postoperative antibiotic prophylaxis, the number of positive swabs was constantly decreasing. In 1 hour a qualitative change in the microflora structure was observed. The number of S. aureus strains reduced. The number of S. epidermidis strains increased to 80 %. And previously undetected Corynebacterium spp. strains were found. In 1 day the conjunctival microflora was represented only by S. epidermidis. In 1 week all the swabs were sterile. In 1 month after phacoemulsification, positive swabs were obtained in 7.7 % (mainly S. epidermidis) only in group 1, where levofloxacin instillations were used as the postoperative antibiotic prophylaxis (р < 0,05). Moxifloxacin, gatifloxacin and antiseptic drugs showed the highest in vitro activity against selected strains.Conclusion. The strains of coagulase-negative staphylococcus S. epidermidis prevailed in conjunctival microflora structure. During the use of postoperative antibiotic prophylaxis, the number of positive swabs is progressively reduced to zero by the 7th day in both groups. A more persistent permanent effect of moxifloxacin, maintaining for 1 month after the operation was found in comparing two patients’ groups received fluoroquinolone eye drops to prevent infection after phacoemulsification.