Abstract
Abstract: :
Purpose: To study the conjunctival normal flora and the possible contamination of the anterior chamber during intraocular surgery, prior to povidone-iodine antisepsis. Methods: Seventy-four eyes from 71 consecutive patients at the General Hospital of Mexico undergoing cataract surgery (59 Extracapusular, 15 Phacoemulsification) were enrolled in this prospective study. Conjunctival smears were obtained on the day of surgery before any preoperative antibiotics or antiseptics. Patients then received a 10% iodine skin prep for 5 minutes and a 5 ml 5% iodine flush with syringe in the conjunctival sac. Before the first incision, a 25-gauge needle through limbus was used to obtain 0.05-0.1 ml of aqueous humor. At the end of the procedure, the anterior chamber tap and conjunctival smear were repeated. Conjunctival swabs were inoculated on blood agar, chocolate agar, and thioglycolate broth. The anterior chamber aspirates were inoculate in Septichek broth, and all specimens were observed for 10 days for bacterial growth. Results: Fifty nine of the 74 (79.7%) preoperative cultures from the conjunctival sac were positive. All of the preoperative anterior chamber fluid taps were negative. However, three of 74 (4.1%) of postoperative cultures of the anterior chamber fluid were positive. Six of 74 (8.1%) of the conjunctival smears were positive at the end of the case. The microorganisms cultured in order of frequency were: Staphylococcus epidermidis (73.2%), Corynebacterium spp. (22.5%), and Micrococcus spp. (4.2%). Conclusion: We found that 80% of patients have conjunctival bacteria preoperatively. After application of 10% iodine on the skin and 5% iodine flush on the conjunctiva, the positive culture rate was reduced to 8%, a 90% relative reduction (72% absolute reduction). Therefore, 5% povidone-iodine flush is an effective disinfectant for preoperative prophylaxis. Additionally, the incidence of anterior chamber contamination for cataract surgery was low (3.8%). This also may be due to the effect of the iodine flush by significantly reducing conjunctival bacteria.
Keywords: 328 bacterial disease • 317 anterior chamber • 468 microbial pathogenesis: clinical studies