The conclusion of the European Society of Cataract and Refractive Surgeons (ESCRS) endophthalmitis study on the prophylaxis of postoperative endophthalmitis following cataract surgery1,2 was perhaps the proudest moment of my professional career. I am eternally grateful to the patients, the clinical partners, the trial coordinator, the statistics team, the data-monitoring group, and the ESCRS for our achievement. It took 10 years from conception to completion, and it is a milestone in the history of cataract surgery.
At the end of each case, patients were randomly allocated to 1 mg intracameral cefuroxime in 0.1 mL of normal saline. They were also randomly allocated, in a masked fashion, to receive intensive perioperative levofloxacin or placebo drops commencing 60 minutes preoperatively and concluding 30 minutes afterward. All patients received preoperative povidone iodine for 3 minutes and routine postoperative levofloxacin drops four times daily for 6 days to prevent wound infection.
An overwhelming benefit from cefuroxime was evident, which achieved a fivefold reduction in endophthalmitis compared with the nonperioperative antibiotic group. The intensive perioperative antibiotic drops were of no statistical benefit, and the routine postoperative levofloxacin drops (for 1 week) were not a study objective factor.
We were all surprised at the high incidence of endophthalmitis (n=0.3%) in the nonperioperative antibiotic group. It would certainly indicate that povidone iodine and routine postoperative antibiotic drops are less effective than we thought and certainly inadequate when compared with intracameral cefuroxime.
During the ESCRS endophthalmitis study, we found a threefold increased risk of endophthalmitis with silicone versus acrylic IOLs. Therefore, I must consider changing from my hitherto routine use of a silicone IOL. This is a major anxiety, and I await the detailed analysis of this risk factor shortly from the ESCRS study group.
MY ENDOPHTHALMITIS PROTOCOL
My personal current protocol is povidone iodine lavage for 3 minutes preoperatively, followed by meticulous application of a steri-drape to ensure all eyelashes are removed from the surgical field.
I have always performed a scleral tunnel incision and feel vindicated by the ESCRS study result,3 which showed that this incision is six times safer than a clear corneal incision. Although there were some caveats in this conclusion, it means—at least—the overall quality of the corneal incision must be enhanced.
I perform coaxial phacoemulsification with bimanual I/A, and I make a clear corneal sideport incision, with a 15º blade. The wounds are not sutured unless leaking occurs.
NINE-DAY SHELF LIFE
At the end of each operation, 1 mg cefuroxime in 0.1 mL of normal saline is injected into the anterior chamber to ensure preoperative prophylaxis. In the hospital pharmacy of St. Vincent's University Hospital, cefuroxime is always mixed under sterile conditions in unit doses of 0.2 mL, containing 2 mg of cefuroxime. The shelf life is 9 days.
In this hospital, the pharmacist mixes an adequate number of cefuroxime syringes (Figure 1) for the week's surgery, which are then stored in the refrigerator of the ophthalmic operating room. The syringes must be kept in sealed sachets and labelled with the dates of manufacture and expiration. The contents of the syringe are sterile, however, the syringe itself is not. The circulating nurse opens the sachet and hands me the syringe. The scrub nurse then attaches a Rycroft cannula (Ellis Ophthalmic Technologies, Inc., Jamaica, New York) and I inject the cefuroxime through the sideport incision, being careful not to touch the eye with my gloves or syringe.
This manufacturing facility is not yet available at the Royal Victoria Eye and Ear Hospital. Here, cefuroxime arrives as a powder. Each vial contains 750 mg; this is diluted with 7.5 mL of water for injection. Next, 0.1 mL of this solution is added to 0.9 mL of a normal saline solution, thus producing a concentration of 1 mg in 0.1 mL for intracameral injection.
MAY CAUSE ERRORS
The latter method is less desirable, as it is prone to errors (ie, dilution, diluent, and possible contamination), however, it is widely practiced in Sweden.4,5 This country has the most experience in the use of intracameral cefuroxime, with more than 400,000 reported cases and the lowest reported incidence of postoperative endophthalmitis.
Ideally, a pharmaceutical company will create a single sterile unit dose of cefuroxime. Until that time, we will have to continue preparing cefuroxime in our practices.
My patients are reviewed on the first postoperative day, at the end of the second postoperative week, at 6 weeks, and at 6 months. They routinely receive topical chloromycetin and dexamethasone drops four times daily for 2-weeks and twice daily for another month.
In summary, the essential changes in my protocol following the ESCRS endophthalmitis study are the (1) adoption of routine intracameral cefuroxime and (2) continued use of scleral tunnel incisions.
Peter Barry, FRCS, is Chairman of the ESCRS Endophthalmitis Study Group, and Consultant Ophthalmic Surgeon, at the Royal Victoria Eye and Ear and St. Vincent's University Hospitals, in Dublin, Ireland. Dr. Barry states that he has no financial interest in the products or companies mentioned. He may be reached at tel: +00 3531 2837203; fax: +00 3531 2838229; or carol.fitzpatrick@escrs.org.
Up Front | Mar 2007
My Protocol for Minimizing the Threat of Endophthalmitis
I have adopted routine intracameral cefuroxime use and continue to perform scleral tunnel incisions.
Peter Barry, FRCS
