The ESCRS endophthalmitis study1,2 on the prophylaxis of endophthalmitis following cataract surgery with phacoemulsification was designed to answer one fundamental question: do perioperative antibiotics prevent endophthalmitis? If so, investigators also sought to determine how the agents should be administered?via intracameral injection, intensive topical drops, or both?
Because withholding any prophylaxis from the control group was considered unethical, all patients received povidone-iodine preoperatively and topical levofloxacin drops q.i.d. for 6 days beginning on the first postoperative day. The study's objectives were the efficacy of the use of intracameral cefuroxime and intensive perioperative antibiotics versus placebo. The objectives did not include the use of povidone-iodine and routine levofloxacin for 1 week postoperatively. Preoperative antibiotic drops were not used in the conventional sense.
The endpoint was the occurrence of infectious endophthalmitis, either clinically diagnosed or proven. All suspect eyes were subjected to a vitreous/anterior chamber tap for gram stain, culture, and polymerase chain reaction. Investigators considered infection proven if any of these three tests were positive.
In the group that did not receive intracameral cefuroxime, the investigators found eight staphylococcal and eight streptococcal infections. In the cefuroxime group, there were three staphylococcal and zero streptococcal infections.
For the eyes infected with Streptococcus, the final visual acuity range was 20/20 to no light perception. Five eyes in the non-cefuroxime group became legally blind, all due to streptococci.
THE EFFECT OF INTRACAMERAL CEFUROXIME
It is not likely that the ESCRS study will result in a major conversion by ophthalmologists from clear corneal to scleral tunnel incisions, although this has always been my standard practice. Rather, the data will likely result in stricter construction and sealing of the corneal wound for surgeons for whom it is preferred practice.
Although it may always be argued that other intracameral agents or alternative systems of drug delivery could be superior to cefuroxime, they will require safety studies and clinical trials to prove their superiority. Given the ESCRS study's results, it may well be impossible for any future clinical trial to deny an intracameral antibiotic to participants. A study to evaluate the comparative benefits of the newer fluoroquinolones applied topically versus using cefuroxime intracamerally would require an enormous and expensive trial, and it may be superfluous if intracameral cefuroxime can achieve the endophthalmitis rate of 0.05 that we have shown. Any such planned studies should also consider the ethics of using the newer fluoroquinolones or vancomycin for prophylaxis. Perhaps they should be considered reserve antibiotics for treatment.
Cefuroxime is not licensed for intraocular use. An exemption certificate was obtained for the purposes of the ESCRS endophthalmitis study.
Peter Barry, FRCS, is Chairman, ESCRS Endophthalmitis Study Group, and also Consultant Ophthalmic Surgeon at Royal Victoria Eye and Ear as well as St. Vincent's University Hospitals, Dublin, Ireland. He acknowledged no financial interest in the products mentioned herein. Mr. Barry may be reached at 353 1 2837203; email@example.com.