Analysis reinforces intracameral antibiotic injection efficacy for preventing postop endophthalmitis

Chicago-Results of a retrospective cohort analysis including data from more than 129,000 eyes that underwent clear corneal phacoemulsification reinforce the efficacy of intracameral antibiotic injection for preventing postoperative endophthalmitis, said Neal Shorstein, MD.

The patients were all members of Kaiser Permanente of Northern California and were operated on by 99 community-based surgeons in 20 surgical centers over the years 2005 to 2012. Use of intracameral antibiotic for endophthalmitis prophylaxis began in late 2007, and overall, intracameral antibiotic was injected in 39.5% of study eyes. A total of 35,631 eyes were injected with cefuroxime, and 19,175 eyes were injected with moxifloxacin.

There were 113 validated cases of endophthalmitis in the series.

Results of an adjusted logistic regression analysis showed that compared with eyes receiving only topical antibiotic, eyes that received intracameral antibiotic in addition to topical drops were about half as likely to develop infection (odds ratio = 0.55).

The intracameral only group had a similar adjusted odds ratio of infection (0.47), although the confidence interval overlapped 1.

“Of all the methods used for prophylaxis of endophthalmitis after cataract surgery, intracameral injection has the strongest evidence base,” said Dr. Shorstein.

An analysis was also conducted comparing the effectiveness of cefuroxime and moxifloxacin.

Using cefuroxime as the reference group, the adjusted odds ratio of developing endophthalmitis in eyes injected with moxifloxacin was somewhat higher, but not statistically significant.

“The paradoxical effect of the increasing adoption of intracameral injection is the plummeting incidence of endophthalmitis, making statistical conclusion of the comparative effectiveness of this already rare complication even more difficult,” Dr. Shorstein said.

In 2013, intracameral antibiotic was used in 79% of cataract surgery cases and the rate of endophthalmitis in 25,000 injected eyes was 1 in 12,000, he noted.