Comparison of 1-day versus 1-hour application of topical neomycin/polymyxin-B before cataract surgery

Antimicrobials and antiseptics: Lowering effect on ocular surface bacterial flora - A systematic review

Topical antimicrobials and antiseptics are used perioperatively to reduce the ocular surface bacteria flora (OSBF) that are involved in the development of post-operative infectious complications. However, their effectiveness is still a controversial topic. This systematic review, performed according to the PRISMA guidelines and registered in PROSPERO, aims to provide an overview of the efficacy of the agents currently used in peri-cataract surgery and -intravitreal injections (IVI) in lowering the OSBF. Although effective in lowering OSBF, perioperative topical antimicrobials are associated with the risk of resistance development, with no obvious additional benefit compared with topical antisepsis. Conversely, the effectiveness of topical antiseptics before cataract surgery and IVI is strongly supported. Based on the available evidence, perioperative antimicrobials are not recommended, whereas the perioperative use of antiseptics is strongly recommended as prophylactic treatment for lowering the infection due to OSBF. Post-operative antimicrobials may be considered in eyes at higher risk for infection.

Analysis of antibiotic resistance and genetic profile of conjunctival bacteria flora before and after cataract surgery

PURPOSE

To analyze antibiotic resistance and genetic profile of conjunctival bacteria flora before and after cataract surgery with the focus on coagulase-negative staphylococci (CNS) during cataract surgery and discuss the implications of this colonization as a potential risk of acquiring endophthalmitis.

METHODS

After approval of the institutional review board and informed consent from patients had been obtained, conjunctival swabs for culture from 59 patients undergoing cataract surgery were taken of the fellow eye at baseline (C0) and from the eye to be operated before (T0) and after (T1) irrigation with povine-iodine 5%, and at the end of surgery (T2). Genes responsible for virulence (mecA, ica and atlE) and antibiotic profile were determined; strain clonality of persistent colonizing Staphylococcus epidermidis strains was established by the Multi-locus sequence typing (MLST).

RESULTS

The frequency of CNS was significantly reduced in T1 (13.6%) from 81.4% in T0 and 86.4% in C0. The frequency of mecA, ica and atlE genes was 34.4%, 37.5% and 61.4%, respectively; and methicillin phenotypic resistance was 35.4%. S. epidermidis was the most frequent species isolated in every time point. MLST revealed in 7 patients 100% coincidence of the seven alleles of the S. epidermidis isolated previous to povine-iodine 5% disinfection and at the end of the surgery. CNS isolates from T1 or T2 corresponded to the same species, antibiotic and virulence profile as those isolates from C0 or T0.

CONCLUSION

Povidone-iodine 5% prophylaxis before surgery significantly reduced conjunctival contamination; in those that persisted, the source of contamination was mostly the patient's microbiota confirmed by the MLST system.

Effect of the administration period of perioperative topical levofloxacin on normal conjunctival bacterial flora

PURPOSE

To assess the long-term and short-term effects of post-cataract surgery antibiotic therapy on the drug-resistance profile of normal conjunctival bacterial flora.

SETTING

Miyata Eye Hospital, Miyazaki, Japan.

DESIGN

Randomized prospective clinical trial.

METHODS

Patients aged 20 years or older who had cataract surgery between May and September 2015 were given levofloxacin 1.5% ophthalmic solution for 3 days preoperatively. The patients were randomly assigned to a 1-week postoperative group or a 1-month postoperative group according to postoperative administration duration. Conjunctival sacs were scraped for bacterial culturing before administration, 1 week postoperatively, at the completion of administration, and 1, 3, and 6 months after administration completion. The bacterial culture growth and minimum inhibitory concentrations (MICs) of levofloxacin against recovered strains of Staphylococcus epidermidis were assessed.

RESULTS

The study enrolled 104 patients. The MICs of levofloxacin against S epidermidis increased during levofloxacin administration compared with before administration in both groups and then declined after administration completion. However, by 3 months, the MICs in the 1-month group were approximately twice those in the 1-week group. Antibiotic susceptibility before administration, at completion of administration, and at 3 months was 73.6%, 20.2%, and 38.5%, respectively, in the 1-week group and 63.0%, 0.0%, and 19.3%, respectively, in the 1-month group. The results indicate that from completion of administration to 3 months, the susceptible strains were approximately 20% lower in the 1-month postoperative group than in the 1-week postoperative group.

CONCLUSION

Administration duration of perioperative levofloxacin 1.5% influenced the MICs and susceptibility of S epidermidis isolated from the conjunctival sac.

Effectiveness of meibomian gland massage combined with topical levofloxacin against ocular surface flora in patients before penetrating ocular surgery

OBJECTIVE

To investigate the bacterial profile in the conjunctiva and meibomian glands in patients before penetrating ocular surgeries, and to compare the anti-bacterial efficacy of 0.5% levofloxacin and its combination with meibomian gland massage.

DESIGN

Hospital-based, case-control study.

PARTICIPANTS

Two hundred and twenty-six eyes from 226 patients with non-infective ocular diseases and scheduled for penetrating ocular surgeries.

METHODS

Tested eyes were administered topical 0.5% levofloxacin (4 times daily) for 2 days. Among them, 91 eyes received meibomian gland massage before levofloxacin application. Samples from the conjunctival sac and meibomian glands were collected for aerobic and anaerobic cultures.

MAIN OUTCOME MEASURES

Culture-positivity and bacterial strains.

RESULTS

Before treatment, aerobes and anaerobes were cultured from 38.5% and 11.0% of the conjunctival samples respectively, compared with 38.5% and 8.8% in the meibomian secretions respectively. Staphylococcus epidermidis and Propionibacterium acnes were the commonest isolated aerobe and anaerobe. Two-day application of levofloxacin reduced aerobic growth to 29.6% in the conjunctiva and 19.3% in the meibomian glands. It had no effect on the anaerobes in these regions (13.3% in the conjunctiva and 10.4% in the meibomian glands). Combined levofloxacin with meibomian gland massage further reduced aerobic growth to 19.8% in the conjunctiva and 11.0% in the meibomian glands. It also drastically decreased anaerobic growth in the meibomian glands (1.1%).

CONCLUSIONS

Meibomian glands carrying considerable bacteria should be considered as a potential source of contamination in ocular surgery. Meibomian gland massage shows additional anti-bacterial effects to topical levofloxacin and could be recommended as a complementary preoperative prophylaxis.

Perioperative antibiotics for prevention of acute endophthalmitis after cataract surgery

BACKGROUND

Endophthalmitis is a severe inflammation of the anterior or posterior (or both) 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.

OBJECTIVES

To evaluate the effects of perioperative antibiotic prophylaxis for endophthalmitis following cataract surgery compared with no prophylaxis or other form of prophylaxis.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 12), Ovid MEDLINE, Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE Daily (January 1946 to December 2016), Embase (January 1980 to December 2016), Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to December 2016),the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We used no date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 6 December 2016. We also searched for additional studies that cited any included trials using the Science Citation Index.

SELECTION CRITERIA

We included randomized controlled trials that enrolled adults undergoing cataract surgery (any method and incision type) for lens opacities due to any origin. We included trials that evaluated preoperative antibiotics, intraoperative (intracameral, subconjunctival or systemic), or postoperative antibiotic prophylaxis for acute endophthalmitis. We excluded studies that evaluated antiseptic preoperative preparations using agents such as povidone iodine or antibiotics for treating acute endophthalmitis after cataract surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed abstracts and full-text articles for eligibility, assessed the risk of bias for each included study, and abstracted data.

MAIN RESULTS

Five studies met the inclusion criteria for this review, including 101,005 adults and 132 endophthalmitis cases. While the sample size was very large, the heterogeneity of the study designs and modes of antibiotic delivery made it impossible to conduct a formal meta-analysis. Interventions investigated included the utility of adding vancomycin and gentamycin to the irrigating solution compared with standard balanced saline solution irrigation alone, use of intracameral cefuroxime with or without topical levofloxacin perioperatively, periocular penicillin injections and topical chloramphenicol-sulfadimidine drops compared with topical antibiotics alone, and mode of antibiotic delivery (subconjunctival versus retrobulbar injections; fixed versus separate instillation of gatifloxacin and prednisolone). The risk of bias among studies was low to unclear due to information not being reported. We identified one ongoing study.Two studies compared any antibiotic with no antibiotic. One study, which compared irrigation with antibiotics in balanced salt solution (BSS) versus BSS alone, was not sufficiently powered to detect differences in endophthalmitis between groups (very low-certainty evidence). One study found reduced risk of endophthalmitis when combining intracameral cefuroxime and topical levofloxacin (risk ratio (RR) 0.14, 95% confidence interval (CI) 0.03 to 0.63; 8106 participants; high-certainty evidence) or using intracameral cefuroxime alone (RR 0.21, CI 0.06 to 0.74; 8110 participants; high-certainty evidence) compared with placebo, and an uncertain effect when using topical levofloxacin alone compared with placebo (RR 0.72, CI 0.32 to 1.61; 8103 participants; moderate-certainty evidence).Two studies found reduced risk of endophthalmitis when combining antibiotic injections during surgery and topical antibiotics compared with topical antibiotics alone (risk ratio (RR) 0.33, 95% confidence interval (CI) 0.12 to 0.92 (periocular penicillin and topical chloramphenicol-sulfadimidine; 6618 participants; moderate-certainty evidence); and RR 0.20, 95% CI 0.04 to 0.91 (intracameral cefuroxime and topical levofloxacin; 8101 participants; high-certainty evidence)).One study, which compared fixed versus separate instillation of gatifloxacin and prednisolone, was not sufficiently powered to detect differences in endophthalmitis between groups (very low-certainty evidence). Another study found no evidence of a difference in endophthalmitis when comparing subconjunctival versus retrobulbar antibiotic injections (RR 0.85, 95% CI 0.55 to 1.32; 77,015 participants; moderate-certainty evidence).Two studies reported any visual acuity outcome; one study, which compared fixed versus separate instillation of gatifloxacin and prednisolone, reported only that mean visual acuity was the same for both groups at 20 days postoperation. In the other study, the difference in the proportion of eyes with final visual acuity greater than 20/40 following endophthalmitis between groups receiving intracameral cefuroxime with or without topical levofloxacin compared with no intracameral cefuroxime was uncertain (RR 0.69, 95% CI 0.22 to 2.11; 29 participants; moderate-certainty evidence).Only one study reported adverse events (1 of 129 eyes had pupillary membrane in front of the intraocular lens and 8 eyes showed posterior capsule opacity). No study reported outcomes related to quality of life or economic outcomes.

AUTHORS' CONCLUSIONS

Multiple measures for preventing endophthalmitis following cataract surgery have been studied. High-certainty evidence shows that injection with cefuroxime with or without topical levofloxacin lowers the chance of endophthalmitis after surgery, and there is moderate-certainty evidence to suggest that using antibiotic eye drops in addition to antibiotic injection probably lowers the chance of endophthalmitis compared with using injections or eye drops alone. Clinical trials with rare outcomes require very large sample sizes and are quite costly to conduct; thus, it is unlikely that many additional clinical trials will be conducted to evaluate currently available prophylaxis. Practitioners should rely on current evidence to make informed decisions regarding prophylaxis choices.

Perioperative Antibiotics to Prevent Acute Endophthalmitis after Ophthalmic Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Post-operative endophthalmitis is a rare and dreaded complication in ophthalmic operations because it often induces irreparable vision loss. Although many ophthalmological studies aimed at reducing the rate of endophthalmitis have been performed around the world, controversy continues to surround some issues, including the choice of antimicrobials and their route of administration, duration and timing. The aim of this study is to investigate some of these unresolved issues.

METHODS

A systematic review and meta-analysis of randomized controlled trials and observational studies was performed. The PubMed, EMBASE, Cochrane Library and Clinical Trials databases were searched to identify studies published until Feb. 2016. The relative risk (RR) for each clinical outcome data is presented with 95% confidence intervals (CIs). Pooled estimates of effects were calculated using random-effect models.

RESULTS

Thirty-four studies from twenty-four reports involving 1264797 eyes were included in this analysis. Endophthalmitis occurred, on average, in one out of 6177 eyes when intracameral vancomycin/moxifloxacin were used and in one out of 1517 eyes when intracameral vancomycin/moxifloxacin were not used. The relative risk (95% CI) of endophthalmitis was reduced to 0.20 (0.10, 0.42) when intracameral antibiotics were used (p<0.0001). The subconjunctival injection of antibiotics was not superior to other administration routes included in this study (RR = 1.67, 95% CI (0.55, 5.05), p = 0.36). A statistically significant difference was found in the rate of endophthalmitis between the use and lack of use of topical antibiotics (RR = 0.65, 95% CI (0.43, 0.99), p = 0.04). However, no statistically significant difference was found in microbial isolation rates between these groups (RR = 0.77, 95% CI (0.34, 1.75), p = 0.53). When long-term and short-term use of topical antibiotics before surgery were compared, a statistically significant difference was found in microbial isolation rates (RR = 0.57, 95% CI (0.44, 0.74), p<0.0001).

CONCLUSIONS

This meta-analysis concluded intracameral antibiotics are effective at preventing endophthalmitis in ocular surgery. A randomized controlled trial confirms the efficacy of cefuroxime but recent large cohort studies support the efficacy of vancomycin/moxifloxacin intracamerally. Intracameral antibitoics are superior to subconjunctival injections but that irrigation antibitoic data are not of enough quality to make a comparison. Different results were found in two clinical outcomes between the use or lack of use of topical antibiotic therapy, we did not find sufficient evidence to conclude that its use prevents endophthalmitis.

Effect of antibiotic prophylaxis on Coagulase-negative Staphylococcus virulence factor profiles in patients undergoing cataract surgery

PURPOSE

In this prospective study, multiplex polymerase chain reaction (PCR) was used to identify genes encoding virulence factors (ica, atlE and mecA) in Coagulase-negative Staphylococcus (CNS) isolates from the ocular microbiota of patients undergoing cataract surgery and to investigate possible changes in the CNS profile due to antibiotic prophylaxis.

METHODS

Between 09/2011 and 08/2013, patients undergoing cataract surgery were recruited at the Department of Ophthalmology, National University of Asuncion, Paraguay. In the eye to be operated on, patients received moxifloxacin 0.5 % eye drops four times at the day before surgery and a last drop 1 hour before surgery (T1). The other eye remained as control (T0). Conjunctival swabs were taken from both eyes 1 hour after the last drop. The presence of genes encoding biofilm formation (ica and atlE) and methicillin resistance (mecA) was detected by a multiplex PCR.

RESULTS

Of the 162 patients (162 study eyes, 162 fellow eye as control group), 87 (53.7 %) eyes were positive for CNS at T0 yielding 96 CNS isolates; 70 eyes (43.2 %) were positive at T1 yielding 77 CNS isolates. For this study, 43 CNS isolates (44.8 %) from T0 and 45 (64.3 %) from T1 were used. Of the total isolates, 81.8 % (72/88) had at least one virulence factor gene (37/43 from T0 and 35/45 from T1) (p = 0.314). Simultaneous detection of ica and atlE genes was higher in T0 (58.0 %) than T1 (46.7 %), but the difference was not significant (p = 0.28).

CONCLUSION

A high frequency of genes encoding virulence factors was observed in the coagulase-negative Staphylococcus isolates. The use of moxifloxacin did not significantly modify the CNS virulence factor profiles.