Endophthalmitis (inflammation of the inside of the eyeball due to infection or trauma) is a rare but potentially blinding complication of cataract surgery. It typically is caused by bacteria that enter the eye during surgery or in the first few days after surgery. Multiple preventive measures are used to try to prevent infection after surgery. Several studies have investigated different modes of prevention such as the types of antibiotics used, how the antibiotics are applied or taken, and when the antibiotics are given in the surgical process.
The authors searched the literature for randomized controlled trials of cataract surgery that evaluated giving antibiotics shortly prior to, during, or immediately after surgery to prevent acute endophthalmitis. Four trials with a total of 100,876 adults and 131 endophthalmitis cases met the inclusion criteria. Of these four trials, two reported reduced rates of endophthalmitis when comparing antibiotics injected into the eye versus antibiotics given in eye drops. In one study, penicillin injected into the eye resulted in a 67% reduction in endophthalmitis after surgery. In the more recent ESCRS study, cefuroxime injected into the eye reduced the risk of endophthalmitis by 80% to 90%, depending on whether antibiotic drops were also utilized. This study provides the best available current evidence for antibiotic prevention of endophthalmitis. Cefuroxime is used widely in Europe but on a limited basis in the United States, where some physicians have expressed concerns regarding risk of contamination or dilution errors during the compounding process (preparing drugs for ocular use) that could cause ocular toxicity (harms).
Given that clinical trials with rare outcomes need to enroll a large number of participants and are costly to conduct, it is unlikely that additional clinical trials will be conducted to assess how well perioperative antibiotic prophylaxis works to prevent acute endophthalmitis after cataract surgery. Practitioners should consider the evidence shown by the ESCRS study, that antibiotics injected into the eye are likely to reduce the risk of endophthalmitis after cataract surgery when they can be sterilely obtained and delivered.
Multiple measures for preventing endophthalmitis following cataract surgery have been studied. One of the included studies, the ESCRS (European Society of Cataract and Refractive Surgeons) study, was performed using contemporary surgical technique and employed cefuroxime, an antibiotic commonly used in many parts of the world. Clinical trials with rare outcomes require very large sample sizes and are quite costly to conduct; thus, it is unlikely that additional clinical trials will be conducted to evaluate currently available prophylaxis. Practitioners should rely on current evidence to make informed decisions regarding prophylaxis choices.
Endophthalmitis is a severe inflammation of the anterior and/or posterior chambers of the eye that may be sterile or associated with infection. It is a potentially vision-threatening complication of cataract surgery. Prophylactic measures for endophthalmitis are targeted against various sources of infection.
The objective of this review was to evaluate the effects of perioperative antibiotic prophylaxis for endophthalmitis following cataract surgery.
We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 10), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE, (January 1950 to October 2012), EMBASE (January 1980 to October 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to October 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 25 October 2012. We also searched for additional studies that cited any included trials using the Science Citation Index.
We included randomized controlled trials that enrolled adults undergoing cataract surgery (any method and incision type) for lens opacities due to any origin. Trials that evaluated preoperative antibiotics, intraoperative (intracameral, subconjunctival or systemic) or postoperative antibiotic prophylaxis for acute endophthalmitis were included. We did not include studies that evaluated antiseptic preoperative preparations using agents such as povidone iodine, nor did we include studies that evaluated antibiotics for treating acute endophthalmitis after cataract surgery.
Two review authors independently reviewed abstracts and full-text articles for eligibility, assessed the risk of bias for each included study, and abstracted data.
Four studies met the inclusion criteria for this review, including 100,876 adults and 131 endophthalmitis cases. While the sample size is very large, the heterogeneity of the study designs and modes of antibiotic delivery made it impossible to conduct a formal meta-analysis. Interventions investigated in the studies included the utility of adding vancomycin and gentamycin to the irrigating solution compared with standard balanced saline solution irrigation alone, use of intracameral cefuroxime and/or topical levofloxacin perioperatively, periocular penicillin injections and topical chloramphenicol-sulphadimidine drops compared with topical antibiotics alone, and mode of antibiotic delivery (subconjunctival versus retrobulbar injections). Two studies with adequate sample sizes to evaluate a rare outcome found reduced risk of endophthalmitis with antibiotic injections during surgery compared with topical antibiotics alone: risk ratio (RR) 0.33, 95% confidence interval (CI) 0.12 to 0.92 (periocular penicillin versus topical chloramphenicol-sulphadimidine) and RR 0.21, 95% CI 0.06 to 0.74 (intracameral cefuroxime versus topical levofloxacin). Another study found no significant difference in endophthalmitis when comparing subconjunctival versus retrobulbar antibiotic injections (RR 0.85, 95% CI 0.55 to 1.32). The fourth study which compared irrigation with balanced salt solution (BSS) alone versus BSS with antibiotics was not sufficiently powered to detect differences in endophthalmitis between groups. The risk of bias among studies was low to unclear due to information not being reported.