Preoperative Topical Gatifloxacin on Anterior Chamber Cultures After Cataract Surgery

Postoperative endophthalmitis, a possible severe complication of cataract surgery, is an infection of the anterior chamber of the eye caused by bacterial contamination and colonization through surgical incisions. Bacteria are thought to originate mainly from the patient's skin and studies show that bacteria are commonly found in the anterior chamber following surgery. However, innate immune defences are usually able to control and eliminate bacterial growth before postoperative endophthalmitis occurs. Also, due to the low incidence of postoperative endophthalmitis, it is difficult to accurately evaluate preventative methods. This study will examine the efficacy of topical preoperative administration of gatifloxacin (a new fourth generation fluoroquinolone antibiotic) on reduction of bacterial contamination of the anterior chamber following cataract surgery. If the antibiotic is shown to lower bacteria count in cultures from anterior chamber fluid, it has the potential to lower the incidence of postoperative endophthalmitis. Patients undergoing cataract surgery will be notified and asked to participate in the study by the physician in advance of the surgery, provided they do not possess any exclusion criteria. The participants will be randomly split into two groups; one group will receive topical application of gatifloxacin prior to surgery, while the other group will receive no eye drops. During surgery, a small sample of anterior chamber fluid will be removed from the eye and cultured in both broth and enrichment media for all subjects. Bacterial growth, i.e., colony forming units (CFUs), will be used as an indicator of the bacterial contamination of the fluid.