A Study on the Efficacy and Corneal Penetration of Besifloxacin in Routine Cataract Surgery Cases

Besifloxacin is a bactericidal fluoroquinolone–type antibiotic that inhibits bacterial enzymes, DNA gyrase and topoisomerase IV. By inhibiting DNA gyrase, DNA replication, transcription, and repair is impaired. By inhibiting topoisomerase IV, decatenation during cell division is impaired. Inhibiting these two targets also slows down development of resistance. AIM: The aim is to study the bactericidal activity on conjunctival flora of topically applied Besifloxacin by two different modes of administration. 1. The Conventional mode of administering one drop of sterile antimicrobial eye drop since two days prior to surgery four times a day (Regimen A) and, 2. The Pulse modeof administration starting an hour immediately preceding surgery – 6 doses delivered every 10 minutes(Regimen B). OBJECTIVES: 1. To determine, the penetration of Besifloxacin in aqueous humour withdrawn from the anterior chamber, by High Performance Liquid Chromatography. 2. To study the prevalence of associated diseases that cause cataract secondarily. 3. To find the type of cataract that prevails more in the study groups. 4. To find the most effective way of administering the drops for better penetration of the eyes. MATERIALS AND METHODS: Study site : Vasan Eye Care Hospital, Tiruchirappalli Study period: The study was conducted during a nine month period. Inclusion criteria: • The subjects of either sex (otherwise healthy) who were scheduled to undergo standard cataract surgery. • 21 years of age or older. • Having a normal or lesser intraocular pressure. • Had the ability to understand and give signed informed consent. Exclusion criteria: • Those that exhibited any intraocular inflammation. • Had a known sensitivity to any of the ingredients in the study medications. • Had a known sensitivity to any quinolone compound. • Had a condition that may confound the study results or may interfere significantly with the subject’s participation in the study. • Had a greater intraocular pressure. • Exhibiting a corneal ulcer, keratitis, or had a history of herpetic keratitis, • Had any ocular disease that would interfere with the evaluation of the study treatments • Received previous intraocular silicone oil. • Was pregnant or nursing. CONCLUSION: Prophylactic antibiotic eye drops are routinely used to prevent postoperative complications like endophthalmitis. Fluoroquinolones in particular have been used extensively due to their excellent activity against ocular pathogens, including both Gram-positive and Gram-negative bacteria. Selection of the most appropriate antibiotic should be based on considerations of pharmacodynamic and pharmacokinetic properties; namely, an agent with a broader spectrum, lower minimum inhibitory concentration (MIC) against pathogens, and better achievable concentration levels in the intraocular tissues should be the agent of choice to achieve optimal efficacy. To summarize current understanding of antibiotic prophylaxis in cataract surgery, with particular emphasis on available evidence and change in practice patterns over the past decade, the fourth generation fluoroquinolone - Besifloxacin was taken up here for determining its antimicrobial potency in the cornea and its ability to penetrate into the anterior chamber. • Results of the present study revealed no association between the grade of cataract and risk factors such as age, duration of diabetes or gender as evident from the correlation coefficient analysis. • NSGC - the Nuclear sclerosis graded cataract emerged as the most commonly found cataract in this hospital. This is followed by PSC – the Posterior subcapsular cataract. • Besifloxacin, the 4th Gen fluoroquinolone, penetrates the conjunctiva when applied topically to the extent of 70.30 % in conventional mode of administration and 74.97 % in the pulse mode of instillation. • With the normal antimicrobial range of Besifloxacin, it is expected to prevent post-surgical endophthalmitis to a great extent. • It’s clearly seen that pulse mode of administration of topical antibiotics an hour preceding surgery shows better penetration of the drug than administered with conventional style of two days prior to surgery. However, there are few studies that have clearly assessed the superiority of one drug over the other among the newer fourth-generation fluoroquinolones, including moxifloxacin and gatifloxacin, when used in humans. Based on current evidence from this study, the recommended measures for endophthalmitis prophylaxis are preoperative topical instillation of fluoroquinolone antibiotic and if need be, intra caramel injection at the end of cataract surgery