Critical Steps for Minimizing Risk of Infection Risk of Endophthalmitis After Intravitreal Drug Injection When Topical Antibiotics Are Not Required: The Diabetic Retinopathy Clinical Research Network Laser-Ranibizumab-Triamcinolone Clinical Trials

Objective: To report the incidence of endophthalmitis after intravitreal drug injection with or without topical antibiotics. Methods: Data from this study were derived from 2 prospective, randomized, clinical trials performed by the Diabetic Retinopathy Clinical Research Network in which patients received intraocular injections of either ranibizumab or triamcinolone. The study protocol required the use of topical Betadine and sterile preparation of the surgical field prior to performance of the injection. Use of preoperative and/or postoperative topical antibiotics was done at the discretion of the ophthalmologist performing the injection. Postoperative monitoring allowed the identification of cases of infectious endophthalmitis, and the results were compared between those patients who did or did not receive preor postoperative antibiotics. Results: 3,226 intravitreal injections of ranibizumab and 612 injections of preservative-free triamcinolone were administered. Topical antibiotics were given on the day of injection in 9.4% of patients. Postoperative treatment with topical antibiotics was prescribed in 21.2% of patients, while 33.3% of patients received topical antibiotics neither before nor after the injection. Three cases of culture-positive endophthalmitis occurred after ranibizumab injection, yielding an overall incidence of 0.09%. No cases occurred after triamcinolone injection. All 3 patients who developed endophthalmitis received topical antibiotics for several days after the injection, but not prior to performance of the procedure. Conclusions: These results suggest that the rate of endophthalmitis following intravitreal drug injection is low when a protocol of topical Betadine and sterile draping of the eye is used. The data do not suggest that topical antibiotics either before or after the procedure alter the rate of infection. Reviewer's Comments: It must be emphasized that sterile preparation of the eye with topical Betadine and maintenance of a sterile field are critical in minimizing the risk of infection. Once that has been accomplished, the study suggests that the further use of topical antibiotics is not necessary. Of course, additional studies were required to definitively answer this question, but in this day in age of ever increasing concern about the cost of medical care, this study suggests that a cost savings can be achieved by elimination of unnecessary antibiotic therapy. (Reviewer-Scott D. Smith, MD, MPH).