Intracameral cefuroxime significantly reduces endophthalmitis rate

Ankara, Turkey-Intracameral cefuroxime instilled at the conclusion of phacoemulsification appears to be safe and effective in reducing the rate of postoperative endophthalmitis, although it is probably not the ideal prophylactic antibiotic, said Güngör Sobaci, MD.

His comments were based on the results of a retrospective study conducted at Gata Hospital, a tertiary referral center affiliated with Gülhane Military Medical Academy and Medical School, Ankara, Turkey, where Dr. Sobaci is a professor of ophthalmology. The study compared outcomes in 3,221 eyes that received intracameral cefuroxime injection (1 mg/0.1 ml) and a control group composed of 3,630 cases in which intracameral cefuroxime was not used.

The rate of presumed endophthalmitis, defined as any unexpectedly intense postoperative inflammation warranting intraocular fluid sampling for microbiologic evaluation, was significantly lower in the group receiving intracameral cefuroxime compared with the controls, 0.12% versus 0.39%. No evidence of allergic reactions, toxic anterior segment syndrome (TASS), or clinically evident macular edema related to use of the intracameral antibiotic was seen.

In the control group, seven of 14 cases of presumed endophthalmitis were culture-positive, and the isolated pathogens in three (43%) of the seven culture-positive cases were fungi and resistant to cefuroxime. In the intracameral cefuroxime group, three (75%) of four cases of presumed endophthalmitis were culture-positive. The isolated strains were Aspergillus fumigatus and Pseudomonas aeruginosa, both of which were resistant to cefuroxime, and Streptococcus pneumoniae, which was sensitive to cefuroxime.

Literature reports

"Use of intracameral cefuroxime was first described in the English-language literature in 2002 by Swedish ophthalmologists, who reported its use decreased the rate of endophthalmitis by almost 10-fold," Dr. Sobaci said. "Recently, the European Society of Cataract and Refractive Surgeons' study group reported use of intracameral cefuroxime was associated with a nearly five-fold reduction in endophthalmitis incidence, and we found a three-fold decrease associated with intracameral cefuroxime use.

"Nevertheless, the occurrence of cases of endophthalmitis caused by pathogens that are considered sensitive to cefuroxime raises concern about resistance and suggests the antimicrobial coverage of cefuroxime is insufficient to exclude the possibility of endophthalmitis after phacoemulsification," Dr. Sobaci added.

"Furthermore, cases of anaphylactic reactions and TASS related to intracameral cefuroxime have been reported," he continued. "Therefore, in accordance with a recent American Society of Cataract and Refractive Surgery survey, we look forward to a commercially available, reasonably priced intracameral antibiotic preparation that will provide sufficient antimicrobial coverage and rule out the safety concerns of homemade intracameral antibiotics."

The control group in the retrospective study was composed of patients operated on between October 2001 and May 2004, before intracameral cefuroxime was used at Gata Hospital during phacoemulsification surgery.

The patients receiving intracameral cefuroxime were operated on between June 2004 and April 2006, although intracameral cefuroxime was not used in patients with a history of penicillin or cephalosporin allergy.

The same ophthalmic surgeons and various senior resident surgeons operated on patients in the two study groups. Preoperative preparation, surgical technique, and postoperative care generally were similar in the two groups.

"We admit the retrospective nature of our study introduces biases, but there were similarities in the number of patients, environment, and follow-up protocols so that we feel it is reasonable to reach conclusions based on our study results," Dr. Sobaci said.

Preoperative regimen

The preoperative regimen included washing of the eyelid and periorbital skin with 10% povidone-iodine solution and instillation of 5% povidone-iodine into the conjunctival sac. Lid margins were draped, and patients received ofloxacin, diclofenac, and prednisolone postoperatively for 2 weeks to 1 month. A subgroup of 355 patients operated on by one surgeon, however, received only topical dexamethasone for 2 weeks.

The cefuroxime was prepared in the operating ward by dilution to 1 mg/0.1 ml with balanced salt solution, and it was instilled through the side port, preferably into the capsular bag, as the last surgical maneuver.

In most eyes, one of two foldable hydrophilic acrylic IOLs (AcrySof MA30, Alcon Laboratories; Sensar AR40-e, Advanced Medical Optics) was implanted using an injector through a 3.2-mm clear corneal incision.

The incision was sutured in a limited number of patients, he said.

"Based on our study design, we also cannot reach conclusions about any possible risks associated with the type of IOL implanted, the incision site, or suturing," Dr. Sobaci said.

PCR

Posterior capsule rupture (PCR) was a common complication among eyes with endophthalmitis in both the group receiving intracameral cefuroxime (two of four eyes, or 50%) and the controls (four of 14 eyes, or 28.5%).

"However, due to the limited number of cases of endophthalmitis in eyes with PCR, we cannot reach any conclusions about the role of PCR as a risk factor for endophthalmitis," Dr. Sobaci said.OT