The role of besifloxacin in the treatment of bacterial conjunctivitis

Antibiotics Versus Placebo for Acute Bacterial Conjunctivitis: Findings From a Cochrane Systematic Review

PURPOSE

To summarize key findings from a Cochrane review of the benefits and safety of antibiotic therapy compared with placebo (or vehicle) for acute bacterial conjunctivitis.

DESIGN

Systematic review and meta-analysis.

METHODS

We included placebo-controlled randomized controlled trials (RCTs) that compared topical antibiotics with placebo. We followed Cochrane methods for trial selection, data extraction, risk of bias assessment, and evidence synthesis.

RESULTS

Twenty-one RCTs involving 8805 participants with acute bacterial conjunctivitis were included. Fifteen (71%) RCTs examined fluoroquinolone (FQ) drops, 3 tested macrolides, alone or in combination with steroids, and another 3 compared other non-FQ antibiotics. Intention-to-treat estimates suggested that compared with placebo, antibiotics may increase clinical recovery by 26% (risk ratio [RR]: 1.26; 95% confidence interval [CI]: 1.09-1.46) at the end of therapy (5 RCTs, 1474 participants). Modified intention-to-treat estimates, in which only participants with laboratory-confirmed bacterial conjunctivitis were analyzed, indicated that antibiotics were associated with 53% higher likelihood of microbiological cure as compared with placebo (RR: 1.53; 95% CI: 1.34-1.74; 10 RCTs, 2827 participants). Non-FQs (RR: 4.05; 95% CI: 1.36-12.00), but not FQs (RR: 0.70; 95% CI: 0.54-0.90), were likely to increase treatment-associated ocular complications such as eye pain, discomfort, and allergic reactions; the certainty of level of evidence was very low.

CONCLUSIONS

Moderate level certainty of evidence suggested that antibiotics may increase the likelihood of clinical recovery and microbiological clearance compared with placebo. Very low-level certainty of evidence suggested that antibiotics may be associated with potential harm in patients with acute bacterial conjunctivitis, but the potential risk of bias from study design, inconsistency in outcome measurement, and reporting limit the evidence to very low certainty.

Antibiotics versus placebo for acute bacterial conjunctivitis

BACKGROUND

Acute bacterial conjunctivitis is an infection of the conjunctiva and is one of the most common ocular disorders in primary care. Antibiotics are generally prescribed on the basis that they may speed recovery, reduce persistence, and prevent keratitis. However, many cases of acute bacterial conjunctivitis are self-limited, resolving without antibiotic therapy. This Cochrane Review was first published in The Cochrane Library in 1999, then updated in 2006, 2012, and 2022.

OBJECTIVES

To assess the benefits and side effects of antibiotic therapy in the management of acute bacterial conjunctivitis.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2022, Issue 5), MEDLINE (January 1950 to May 2022), Embase (January 1980 to May 2022), 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 in May 2022.   SELECTION CRITERIA: We included randomized controlled trials (RCTs) in which any form of antibiotic treatment, with or without steroid, had been compared with placebo/vehicle in the management of acute bacterial conjunctivitis. This included topical and systemic antibiotic treatments.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed the titles and abstracts of identified studies. We assessed the full text of all potentially relevant studies and determined the included RCTs, which were further assessed for risk of bias using Cochrane methodology. We performed data extraction in a standardized manner and conducted random-effects meta-analyses using RevMan Web.

MAIN RESULTS

We included 21 eligible RCTs, 10 of which were newly identified in this update. A total of 8805 participants were randomized. All treatments were topical in the form of drops or ointment. The trials were heterogeneous in terms of their eligibility criteria, the nature of the intervention (antibiotic drug class, which included fluoroquinolones [FQs] and non-FQs; dosage frequency; duration of treatment), the outcomes assessed and the time points of assessment. We judged one trial to be of high risk of bias, four as low risk of bias, and the others as raising some concerns. Based on intention-to-treat (ITT) population, antibiotics likely improved clinical cure (resolution of clinical symptoms or signs) by 26% (RR 1.26, 95% CI 1.09 to 1.46; 5 trials, 1474 participants; moderate certainty) as compared with placebo. Subgroup analysis showed no differences by antibiotic class (P = 0.67) or treatment duration (P = 0.60). In the placebo group, 55.5% (408/735) of participants had spontaneous clinical resolution by days 4 to 9 versus 68.2% (504/739) of participants treated with an antibiotic. Based on modified ITT population, in which participants were analyzed after randomization on the basis of positive microbiological culture, antibiotics likely increased microbiological cure (RR 1.53, 95% CI 1.34 to 1.74; 10 trials, 2827 participants) compared with placebo at the end of therapy; there were no subgroup differences by drug class (P = 0.60). No study evaluated the cost-effectiveness of antibiotic treatment. Patients receiving antibiotics had a lower risk of treatment incompletion than those in the placebo group (RR 0.64, 95% CI 0.52 to 0.78; 13 trials, 5573 participants; moderate certainty) and were 27% less likely to have persistent clinical infection (RR 0.73, 95% CI 0.65 to 0.81; 19 trials, 5280 participants; moderate certainty). There was no evidence of serious systemic side effects reported in either the antibiotic or placebo group (very low certainty). When compared with placebo, FQs (RR 0.70, 95% CI 0.54 to 0.90) but not non-FQs (RR 4.05, 95% CI 1.36 to 12.00) may result in fewer participants with ocular side effects. However, the estimated effects were of very low certainty.

AUTHORS' CONCLUSIONS

The findings of this update suggest that the use of topical antibiotics is associated with a modestly improved chance of resolution in comparison to the use of placebo. Since no evidence of serious side effects was reported, use of antibiotics may therefore be considered to achieve better clinical and microbiologic efficacy than placebo. Increasing the proportion of participants with clinical cure or increasing the speed of recovery or both are important for individual return to work or school, allowing people to regain quality of life. Future studies may examine antiseptic treatments with topical antibiotics for reasons of cost and growing antibiotic resistance.

Besifloxacin-loaded ocular nanoemulsions: design, formulation and efficacy evaluation

The purpose of this study was to develop and evaluate nanoemulsions (NEs) containing besifloxacin for ocular drug delivery. Pseudo ternary phase diagrams were constructed using Triacetin (oil), Cremophor® RH 40 (surfactant), and Transcutol®P (co-surfactant) to identify NE regions. Six formulations were developed by low-energy emulsification method and then evaluated for size, refractive index, pH, osmolality, viscosity, and drug release. After accelerated physical stability and bovine conrneal permeation studies, NE2 was chosen as optimized formulation forantimicrobial efficacy, and hen's egg test-chorioallantoic membrane (HET-CAM) tests. The particle size of optimum NE was 14 nm with a narrow size distribution. Moreover, other physicochemical characterizations were in the acceptable range for ocular administration. Besifloxacin-loaded NEs demonstrated sustained release pattern and 1.7-fold higher permeation compared with the control suspension in the ex vivo transcorneal permeation study. HET-CAM test indicated no irritation, and HL% revealed no damage to the tissue, so the optimum NE is well tolerated by the eye. In vitro antimicrobial evaluation, showed comparative efficacy of lower drug-loaded NE (0.2%) versus 0.6% besifloxacin suspension (equal concentration to commercial besifloxacin eye drop). In conclusion, besifloxacin-loaded NEs could be considered as a suitable alternative to the marketed suspension for treating bacterial eyeinfections.

The prevalence and characteristics of chronic ocular itch: a cross-sectional survey

Introduction

In this cross-sectional study, we aimed to determine the prevalence and characteristics of chronic ocular itch in an outpatient ophthalmology and optometry clinic.

Methods

Four hundred patients from an outpatient ophthalmology and optometry clinic were enrolled. The presence and characteristics of chronic ocular itch were assessed by a questionnaire. Data regarding ophthalmologic, dermatologic, and systemic conditions as well as current medications were extracted from medical records.

Results

Chronic ocular itch was present in 118 (29.5%) of 400 participants. Chronic ocular pruritus was significantly more prevalent in females [P=0.015; odds ratio (OR)=1.8; 95% confidence interval (CI), 1.1-2.8] and was significantly associated with the presence of allergic conjunctivitis [51.8% (n=45); P<0.001; OR=5.0; 95% CI, 3.0-8.3], dry eye syndrome [40.1% (75); P<0.001; OR=2.6; 95% CI, 1.7-4.1], blepharitis [43.8% (n=21); P=0.021; OR=2.0; 95% CI, 1.1-3.8], and atopic dermatitis [50.0% (n=10); P=0.023; OR=2.6; 95% CI, 1.1-5.8]. Chronic ocular itch was not significantly associated with systemic conditions, or the use of prescribed ophthalmologic medications.

Discussion

Chronic ocular itch is common and may be related to ophthalmologic or dermatologic pathologies. The present findings highlight the importance of identifying and managing this uncomfortable symptom that may negatively impact the quality of life and sleep of affected patients.