A cluster of cases of postoperative endophthalmitis at the Prince Charles Eye Unit, King Edward Hospital, Windsor, England, over a 4-month period led to a thorough investigation of etiologic factors and multiple changes in the perioperative routines.
From December 2003 to May 2004, nine cases of postoperative endophthalmitis occurred in patients who had undergone cataract surgery at the Prince Charles Eye Unit, King Edward Hospital, Windsor, England, according to Dr. Packard. That cluster of postoperative endophthalmitis cases during a 4-month period led to a comprehensive investigation of surgical practices and patient-related factors in an effort to identify changes that could be implemented to reduce the risk of that postoperative complication. A team of investigators from the Royal College of Ophthalmologists assisted in the review.
Prospective data collected since the end of May 2004, when changes were initiated, showed that among 9,704 cataract surgeries performed by 36 different surgeons, three cases of suspected postoperative endophthalmitis were found, representing an incidence of 0.030%. All three cases were negative by Gram stain and culture, but were treated with intravitreal antibiotics, and all three eyes recovered good unaided vision with an outcome of 6/9 or better.
"Since we made many modifications simultaneously, it is impossible to define which was most important," he said. "However, considering the published literature, particularly the experience in Sweden and the European Society of Cataract and Refractive Surgeons prospective postoperative endophthalmitis prophylaxis study, intracameral cefuroxime almost certainly played a significant role."
Factors considered in the investigation to determine the etiology of the original postoperative endophthalmitis cluster included those relating to practices of surgeons and nurses, type of anesthesia and incision, instruments used, patient factors, and surgical complications. The off-site sterilization facility used by the cataract surgery center also was involved in the investigation.
No patterns were observed in any of the areas evaluated. No single surgeon or nurse was implicated in the nine original cases, nor was any single type of incision, phaco machine, or handpiece over-represented. No association was identified relating to whether or not surgical masks were used, and intraoperative complications occurred in only two of the nine cases, Dr. Packard said.
In addition to starting use of intracameral cefuroxime for antibiotic prophylaxis, other changes instituted at the Prince Charles Eye Unit included the introduction of specially designed trays that would eliminate the development of condensation after sterilization, changing of the timing of the preoperative application of povidone-iodine 5% in relation to the topical anesthetic gel, and use of disposable bimanual irrigation/aspiration handpieces. Topical antibiotic was switched from ciprofloxacin (Ciloxan, Alcon Laboratories) to ofloxacin (Ocuflox, Allergan), and the fluoroquinolone was instilled on the day of surgery, at completion of the case, and then for 1 week postoperatively.
"It must be remembered that no fourth-generation fluoroquinolone is available in Europe," Dr. Packard said. "Ofloxacin offers better ocular penetration than ciprofloxacin, but use of intracameral antibiotic is a good way to deliver a high level of medication to the target site during the vulnerable period immediately after surgery."
Cefuroxime is instilled intracamerally after the eye is refilled with balanced salt solution, and then the conjunctival fornices are sterilized with povidone-iodine 5% at the end of the case.
"The latter measure also serves as a Seidel test for wound leakage, allowing surgeons to verify wound closure," Dr. Packard concluded.