Ofloxacin compared with chloramphenicol in the management of external ocular infection

Topical Lomefloxacin versus Topical Chloramphenicol in the Treatment of Acute Bacterial Conjunctivitis

We performed a prospective, randomised, investigator-masked and parallel-group study to compare topical lomefloxacin 0.3% instilled twice daily with topical chloramphenicol instilled five times daily in the treatment of acute bacterial conjunctivitis. 191 patients (lomefloxacin 96, chloramphenicol 95) were enrolled in this study with clinically diagnosed acute bacterial conjunctivitis. The two treatment groups were similar at baseline. The treatments were equally effective and significantly (p < 0.001) reduced the Cumulative Sum Score of the clinical signs and symptoms of bacterial conjunctivitis. At the end of the trial, there was no difference between the two treatments in the Cumulative Sum Score of signs and symptoms (p = 0.63), and the investigator (p = 0.28) and patients' (p = 0.50) assessments of the success of therapy. The two drugs were equally well tolerated locally, with no serious systemic or local adverse drug reactions reported in any study patient. Bacteriological confirmation of acute conjunctivitis was possible in 96 patients (lomefloxacin 47, chloramphenicol 49) out of the 191 enrolled. Both treatments significantly (p < 0.001) reduced the conjunctival bacterial colony count score with no difference (p = 0.12) between the two treatment groups. In conclusion, lomefloxacin 0.3% eye drops instilled twice daily were as effective and well tolerated as chloramphenicol 0.5% eye drops instilled 5 times daily in the treatment of acute bacterial conjunctivitis.

Interventions for chronic blepharitis

BACKGROUND

Blepharitis, an inflammatory condition associated with itchiness, redness, flaking, and crusting of the eyelids, is a common eye condition that affects both children and adults. It is common in all ethnic groups and across all ages. Although infrequent, blepharitis can lead to permanent alterations to the eyelid margin or vision loss from superficial keratopathy (abnormality of the cornea), corneal neovascularization, and ulceration. Most importantly, blepharitis frequently causes significant ocular symptoms such as burning sensation, irritation, tearing, and red eyes as well as visual problems such as photophobia and blurred vision. The exact etiopathogenesis is unknown, but suspected to be multifactorial, including chronic low-grade infections of the ocular surface with bacteria, infestations with certain parasites such as demodex, and inflammatory skin conditions such as atopy and seborrhea. Blepharitis can be categorized in several different ways. First, categorization is based on the length of disease process: acute or chronic blepharitis. Second, categorization is based on the anatomical location of disease: anterior, or front of the eye (e.g. staphylococcal and seborrheic blepharitis), and posterior, or back of the eye (e.g. meibomian gland dysfunction (MGD)). This review focuses on chronic blepharitis and stratifies anterior and posterior blepharitis.

OBJECTIVES

To examine the effectiveness of interventions in the treatment of chronic blepharitis.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 1), MEDLINE (January 1950 to February 2012), EMBASE (January 1980 to February 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 searched the reference lists of included studies for any additional studies not identified by the electronic searches. There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 9 February 2012.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-randomized controlled trials (CCTs) in which participants were adults aged 16 years or older and clinically diagnosed with chronic blepharitis. We also included trials where participants with chronic blepharitis were a subset of the participants included in the study and data were reported separately for these participants. Interventions within the scope of this review included medical treatment and lid hygiene measures.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed search results, reviewed full-text copies for eligibility, examined risk of bias, and extracted data. Data were meta-analyzed for studies comparing similar interventions and reporting comparable outcomes with the same timing. Otherwise, results for included studies were summarized in the text.

MAIN RESULTS

There were 34 studies (2169 participants with blepharitis) included in this review: 20 studies (14 RCTs and 6 CCTs) included 1661 participants with anterior or mixed blepharitis and 14 studies (12 RCTs and 2 CCTs) included 508 participants with posterior blepharitis (MGD). Due to the heterogeneity of study characteristics among the included studies, with respect to follow-up periods and types of interventions, comparisons, and condition of participants, our ability to perform meta-analyses was limited. Topical antibiotics were shown to provide some symptomatic relief and were effective in eradicating bacteria from the eyelid margin for anterior blepharitis. Lid hygiene may provide symptomatic relief for anterior and posterior blepharitis. The effectiveness of other treatments for blepharitis, such as topical steroids and oral antibiotics, were inconclusive.

AUTHORS' CONCLUSIONS

Despite identifying 34 trials related to treatments for blepharitis, there is no strong evidence for any of the treatments in terms of curing chronic blepharitis. Commercial products are marketed to consumers and prescribed to patients without substantial evidence of effectiveness. Further research is needed to evaluate the effectiveness of such treatments. Any RCT designed for this purpose should separate participants by type of condition (e.g. staphylococcal blepharitis or MGD) in order to minimize imbalances between groups (type I errors) and to achieve statistical power for analyses (prevent type II errors). Medical interventions and commercial products should be compared with conventional lid hygiene measures, such as warm compresses and eyelid margin washing, to determine effectiveness, as well as head-to-head to show comparative effectiveness between treatments. Outcomes of interest should be patient-centered and measured using validated questionnaires or scales. It is important that participants be followed long-term, at least one year, to assess chronic outcomes properly.

Acute infectious conjunctivitis in childhood

OBJECTIVE

To review the etiology, clinical features and management of acute infectious conjunctivitis in children after the newborn period.

DATA SOURCES

Articles obtained from MEDLINE published before March 2000.

DATA SELECTION AND EXTRACTION

Representative articles on the etiology and clinical features were selected. Twenty-four clinical trials were also selected. From these articles, the main findings from three placebo controlled trials and two comparative clinical trials involving children are summarized in detail. The main findings from 19 comparative clinical trials in adults are briefly summarized.

DATA SYNTHESIS AND CONCLUSIONS

Acute infectious conjunctivitis caused by bacteria or viruses is a very common problem in children after the neonatal period. The most common bacterial pathogens are nontypable Haemophilus influenzae and Streptococcus pneumoniae. Diagnostic microbiology tests are not indicated for uncomplicated cases but may be useful for very young or very ill children if there is no response to initial therapy; for nosocomial cases; for cases suspected to be caused by sexually transmitted pathogens; and for outbreaks. Conjunctivitis is usually a mild, self-limited disease, but topical antibiotics are superior to placebo in reducing the duration and severity of symptoms. Most topical agents have equivalent efficacy; therefore, the selection of first-line agents should include inexpensive drugs with few adverse effects. Good choices include polymyxin/gramicidin, polymyxin/trimethoprim or sulfacetamide. Referral to an ophthalmologist should be considered in situations in which the diagnosis of uncomplicated conjunctivitis is in doubt or if there is no prompt response to therapy.

Phase III efficacy and safety study of besifloxacin ophthalmic suspension 0.6% in the treatment of bacterial conjunctivitis

OBJECTIVE

To compare the clinical and antimicrobial efficacy of besifloxacin ophthalmic suspension 0.6% with that of vehicle in the treatment of bacterial conjunctivitis.

RESEARCH DESIGN AND METHODS

This was a randomized, multicenter, double-masked, vehicle-controlled study. A total of 957 patients aged 1 year and older with bacterial conjunctivitis were randomized to treatment with besifloxacin ophthalmic suspension 0.6% or vehicle applied topically three times daily for 5 days.

MAIN OUTCOME MEASURES

Primary endpoints were clinical resolution and microbial eradication of baseline bacterial infection at Visit 2 (Day 5 +/- 1). Secondary endpoints included clinical resolution and microbial eradication at Visit 3 (Day 8 or 9), individual clinical outcomes at follow-up visits, and safety.

CLINICAL TRIAL REGISTRATION

NCT number, NCT00347932.

RESULTS

Three hundred and ninety patients had culture-confirmed bacterial conjunctivitis. Clinical resolution and microbial eradication were significantly greater with besifloxacin ophthalmic suspension than with vehicle at Visit 2 (45.2% vs. 33.0%, p = 0.0084; and 91.5% vs. 59.7%, p < 0.0001, respectively) and Visit 3 (84.4% vs. 69.1%, p = 0.0011; and 88.4% vs. 71.7%, p < 0.0001, respectively). Results for secondary endpoints of individual clinical outcomes were consistent with primary endpoints. Fewer eyes receiving besifloxacin ophthalmic suspension experienced adverse events than those receiving vehicle (9.2% vs. 13.9%; p = 0.0047).

CONCLUSIONS

Besifloxacin ophthalmic suspension produces clinical resolution and microbial eradication rates significantly better than vehicle and is safe for the treatment of bacterial conjunctivitis.

LIMITATIONS

A limitation of this study is the lack of a non-treatment control group.

Inner eyelid surface temperature as a function of warm compress methodology

PURPOSE

To (1) determine an optimal method of warm compress (WC) application to maximize heating meibomian glands in minimal time, (2) determine the maximum inner eyelid temperature achievable during 30 min of routine WC application, (3) examine the cooling curve for 10 min after WCs have been discontinued.

METHODS

Subjects were randomly assigned to one of three WC methodologies. Group A (GrA), (n = 10): 15 min WC application without reheating. GrB, (n = 10): 30 min WC application with reheating every 2 min. GrC, (n = 12): 30 min WC application optimizing contact with the lower lid and reheating every 2 min. WCs were heated to 45 +/- 0.5 degrees C. Outer and inner lower eyelid surface temperatures were measured at baseline and regular intervals.

RESULTS

GrA: the maximum outer and inner lower eyelid surface temperatures = 41.2 +/- 0.3 degrees C at 1 min and 38.8 +/- 0.2 degrees C after 4 min, respectively. GrB: the maximum outer upper eyelid temperature, 43.3 +/- 0.5 degrees C, was reached after 6 min while it required 30 min to reach the maximum inner lower eyelid temperature, 40.4 +/- 0.3 degrees C. GrC: it required 4 min to reach the maximum outer lower eyelid temperature, 42.2 +/- 0.4 degrees C, while it required 20 min to reach the maximum inner lower eyelid temperature, 40.8 +/- 0.3 degrees C.

CONCLUSIONS

To optimize WC efficiency, patients should (1) heat the WC to approximately 45 degrees C, (2) optimize contact between the WC and outer eyelid surfaces, (3) reheat the WC frequently and have a replacement heated WC on hand for exchange, and (4) perform the activity for at least 4 min in order to achieve an inner lower eyelid temperature > or = 40 degrees C. Longer therapy may be necessary for more severe obstructions. These data suggest that precise, customized, labor-intensive WC procedure is necessary to optimize treating meibomian gland dysfunction and obstruction using WCs.

A randomised controlled trial of management strategies for acute infective conjunctivitis in general practice

OBJECTIVE

To assess different management strategies for acute infective conjunctivitis.

DESIGN

Open, factorial, randomised controlled trial.

SETTING

30 general practices in southern England.

PARTICIPANTS

307 adults and children with acute infective conjunctivitis.

INTERVENTION

One of three antibiotic prescribing strategies-immediate antibiotics (chloramphenicol eye drops; n = 104), no antibiotics (controls; n = 94), or delayed antibiotics (n = 109); a patient information leaflet or not; and an eye swab or not.

MAIN OUTCOME MEASURES

Severity of symptoms on days 1-3 after consultation, duration of symptoms, and belief in the effectiveness of antibiotics for eye infections.

RESULTS

Prescribing strategies did not affect the severity of symptoms but duration of moderate symptoms was less with antibiotics: no antibiotics (controls) 4.8 days, immediate antibiotics 3.3 days (risk ratio 0.7, 95% confidence interval 0.6 to 0.8), delayed antibiotics 3.9 days (0.8, 0.7 to 0.9). Compared with no initial offer of antibiotics, antibiotic use was higher in the immediate antibiotic group: controls 30%, immediate antibiotics 99% (odds ratio 185.4, 23.9 to 1439.2), delayed antibiotics 53% (2.9, 1.4 to 5.7), as was belief in the effectiveness of antibiotics: controls 47%, immediate antibiotics 67% (odds ratio 2.4, 1.1 to 5.0), delayed antibiotics 55% (1.4, 0.7 to 3.0), and intention to reattend for eye infections: controls 40%, immediate antibiotics 68% (3.2, 1.6 to 6.4), delayed antibiotics 41% (1.0, 0.5 to 2.0). A patient information leaflet or eye swab had no effect on the main outcomes. Reattendance within two weeks was less in the delayed compared with immediate antibiotic group: 0.3 (0.1 to 1.0) v 0.7 (0.3 to 1.6).

CONCLUSIONS

Delayed prescribing of antibiotics is probably the most appropriate strategy for managing acute conjunctivitis in primary care. It reduces antibiotic use, shows no evidence of medicalisation, provides similar duration and severity of symptoms to immediate prescribing, and reduces reattendance for eye infections.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN32956955 [controlled-trials.com].

Penetration of topically applied levofloxacin 0.5% and ofloxacin 0.3% into the vitreous of the non-inflamed human eye

BACKGROUND

The aim of the study was to evaluate the vitreous penetration of two commercially available ophthalmic fluoroquinolones: ofloxacin and levofloxacin.

METHODS

This prospective, double-blind, randomized clinical trial comprised 16 patients scheduled for vitrectomy surgery of one eye for macular hole or macular pucker. The patients were randomly assigned to receive topical ofloxacin 0.3% (n=9) or levofloxacin 0.5% (n=7) the day before, one drop at noon, 4 p.m., 8 p.m. and midnight. The next morning, patients were given their assigned masked antibiotic every 5 min for four doses starting 1 h before surgery. The vitreous humour samples, at least 0.3 ml each, were collected 1 h after the administration of the last dose, at the beginning of the pars plana vitrectomy with infusion disconnected. Samples were assayed for ofloxacin and levofloxacin concentrations by a method using high-performance liquid chromatography (HPLC) coupled with single mass spectrometry with electrospray ionization

RESULTS

Equal topical administration of levofloxacin yielded 2.5 times higher vitreal concentration than ofloxacin. The mean vitreous concentrations of ofloxacin and levofloxacin were 5.30+/-3.04 (SD) ng/ml and 13.09+/-5.24 ng/ml, respectively (P=0.002).

CONCLUSIONS

Equal dosing with topical administration of levofloxacin 0.5% and ofloxacin 0.3% allows better penetration into the vitreous for levofloxacin, but the levels of mean concentrations of each drug did not exceed the MIC(90) or MIC(50) for most ocular pathogenic bacteria in terms of conventional endophthalmitis therapy.

Evidence-based practice in acute ophthalmology

AIM

To study the overall level of evidence-based practice in an accident and emergency eye unit in the UK and evaluate the extent of evidence-based practice by ophthalmologists and nurse practitioners (NPs).

METHODS

The case notes of all new patients attending our accident and emergency department for a period of 1 week were reviewed prospectively. For each case, the diagnosis at presentation and its intervention was ascertained. A literature search using Medline and Cochrane library was performed to assess the level of evidence provided for each diagnosis-intervention pair. Each diagnosis-intervention pair was evaluated and graded to assess the best level of evidence provided.

RESULTS

A total of 474 new patients attended the eye casualty during the study period. No diagnosis was made in 27 cases and they were excluded from the analysis. Out of 447 patients, 308 (68.9%) cases were managed by NPs and 139 (31.1%) by doctors. A total of 294 (65.8%) patient interventions were based on evidence from systematic reviews, meta-analysis and randomised-controlled trials, of which 223 were managed by NPs and 71 by ophthalmologists. This difference was statistically significant with P<0.001. One hundred and seven (23.9%) interventions were supported by evidence from prospective and retrospective trials.

CONCLUSION

This study demonstrated that two-thirds of interventions were based on the highest level of evidence and was comparable to studies performed in other specialities. It also highlights the advanced role of trained NPs in acute ophthalmology.

Comparison of antibiotic drops placed in the conjunctival cul-de-sac to antibiotic ointment applied to the lid margin in reduction of bacterial colonization on the lid margin

PURPOSE

To compare the efficacy of antibiotic drops placed in the conjunctival cul-de-sac to antibiotic ointment applied to the lid margin in reduction of bacterial colonization on the lid margin.

METHODS

A randomized, prospective, single-masked study was conducted on 19 patients with culture-proven colonization of bacteria on the lid margins. Ophthalmic eligibility criteria included the presence of > or =50 colony-forming units/mL (CFU/mL) of bacteria on both right and left lids. Each patient received one drop of ofloxacin in one eye every night for one week, followed by one drop once a week for one month. In the same manner, each patient received bacitracin ointment (erythromycin or gentamicin ointment if lid margin bacteria were resistant to bacitracin) to the lid margin of the fellow eye. Quantitative lid cultures were taken at initial visit, one week, one month, and two months. Fifteen volunteers (30 lids) served as controls. Lid cultures were taken at initial visit, one week, and one month.

RESULTS

Both antibiotic drop and ointment reduced average bacterial CFU/mL at one week and one month. Average bacterial CFU/mL reestablished to baseline values at two months. There was no statistically significant difference between antibiotic drop and ointment in reducing bacterial colonization on the lid margin.

CONCLUSION

Antibiotic drops placed in the conjunctival cul-de-sac appear to be as effective as ointment applied to the lid margins in reducing bacterial colonization in patients with > or =50 CFU/mL of bacteria on the lid margins.

Treatment of ocular infections with topical antibacterials

Topically applied ophthalmic antibacterial preparations are widely used in the treatment of patients with superficial ocular infections. In addition, they are frequently used to augment treatment for intraocular infection administered systemically or via local instillation. Direct application delivers high concentrations of antimicrobial agents to the surface of the eye conveniently, quickly and with minimal systemic exposure to the agent. However, antibacterials are rapidly dissipated from the tear film and intraocular penetration of topical antibacterial agents is generally poor, necessitating intensive application for successful treatment of corneal infections. Therapeutic concentrations are rarely achieved at other sites in the eye. This article reviews what is known of the pharmacokinetics of topical ocular agents and how this information can be used to optimise ocular persistence and penetration and minimise systemic absorption of antibacterials. A review of the features of the most commonly employed topical antibacterials suggests that for the treatment of uncomplicated bacterial conjunctivitis there is little difference between the various agents in terms of clinical efficacy, although chloram-phenicol should be used with care because of its potential haematological toxicity. Carefully considered therapy is imperative for bacterial keratitis; fortified beta-lactam/aminoglycoside combinations are often used for these infections. The fluoroquinolones appear promising, but caution is necessary in treating keratitis of unknown aetiology with these agents alone because of inherent and emerging acquired resistance among Gram-positive bacteria.

Corneal tissue levels of topically applied ofloxacin

PURPOSE

To evaluate the levels of ofloxacin (Ocuflox) in human corneal tissue in patients exposed to various dosing regimens and application methods.

SETTING

Corneal Consultants of Indiana, Indianapolis, Indiana, USA.

METHODS

Forty patients meeting inclusion criteria were recruited from persons scheduled to have penetrating keratoplasty (PKP). Patients were placed into one of two study groups of 20 each based on dosing regimen and application method. The SAS GLM (General Linear Models) procedure was used to test for differences in mean Ocuflox tissue concentration among study groups and for interaction effects of preoperative diagnosis, trephine size, dosing regimen, and corneal integrity.

RESULTS

Corneal tissue concentrations of Ocuflox were elevated significantly by varying drug application methods and dosing schedules before PKP. Eyes receiving medication every 15 minutes for 4 hours had significantly higher levels of Ocuflox than those receiving the drug in six doses over 24 hours before surgery. Ocuflox concentrations exceeded the MIC90 (minimum inhibitory concentration) for key ocular pathogens in essentially all cornea specimens studied.

CONCLUSION

Ocuflox penetration was improved by administering it in a controlled setting at 15 minute intervals over 4 hours. The drug provided high tissue levels in both the cornea and aqueous humor, which together with its broad range of antibacterial coverage, should make it a good choice for prophylactic treatment.

Topical lomefloxacin twice daily compared with fucidic acid in acute bacterial conjunctivitis

Forty-five patients with presumed acute bacterial conjunctivitis were treated in an investigator-masked randomized multicenter study with either lomefloxacin 0.3% or fucidic acid 1% eye drops twice daily. Clinical signs and symptoms were rated by slit-lamp examination and conjunctival swab cultures were performed to evaluate clinical and microbiological efficacy. A total of 57 ocular isolates were tested for susceptibility to nine antibiotics. A significant decrease in clinical symptomatology was achieved by both treatments with a gradual improvement over the treatment period of 7-9 days. Bacteriological recovery was frequently achieved already at the first control visit (day 3-5), but the recovery rate was statistically significant (p = 0.014) only in the lomefloxacin group. The relatively high in vitro resistance rate (46%) to fucidic acid was not reflected by lower clinical efficacy. Two unrelated adverse events (one in each treatment group) and minimal local intolerance problems were observed in both treatment groups. A significantly higher incidence of burning sensation was observed with fucidic acid than with lomefloxacin (p < 0.01). All four treatment failures in the study occurred in the fucidic acid group. Lomefloxacin 0.3% ophthalmic solution demonstrated a high efficacy and good tolerance in the management of acute bacterial conjunctivitis.

Photoreactivity of chloramphenicol in vitro and in vivo

The negative side effects of chloramphenicol (CAP) mostly involve blood dyscrasias (e.g. irreversible non-dose-dependent aplastic anemia), allergic skin reactions and eye damage. To learn the cause of these side effects, most research focuses on metabolically formed nitroso- and hydroxylamino derivatives in the predisposed patient. In previous investigations it was demonstrated that photochemical decomposition of CAP in vitro by UV-A leads to formation of p-nitrobenzaldehyde (pNB), p-nitrobenzoic acid (pNBA) and p-nitrosobenzoic acid (pNOBA); the latter comprises up to 45 mol% of the starting amount of CAP. Incubation of these photoproducts in rat blood showed that pNB and pNOBA rapidly react and that PNBA is stable under these conditions. Reaction products from pNB (half-life 1.7 min) proved to be pNBA and p-nitrobenzyl alcohol (pNBOH) while pNOBA (half-life 3.7 min) was converted into p-aminobenzoic acid (pABA). Exposure of CAP in rat blood to UV-A yielded the same end products: pNBA, pABA and pNBOH. To estimate the amount of oxidative stress generated in vivo by these compounds, the ability to form methemoglobin (MetHb) in erythrocytes was tested; only pNOBA and p-hydroxylaminobenzoic acid (pHABA), a possible intermediate in the decomposition of pNOBA, proved to be reactive. Ultraviolet-A exposure of rats, after intraperitoneal injection of CAP, led to 3.6 times the basic level of MetHb. In addition, covalent binding of 3H-labeled CAP photoproducts to the skin of the back and to the ears was found, which was 9.1 and 3.2 times higher, respectively, than the dark values.(ABSTRACT TRUNCATED AT 250 WORDS)

Ocular penetration of topical ciprofloxacin and norfloxacin drops and their effect upon eyelid flora

A double blind, prospective study was undertaken to compare aqueous humour penetration of topical 0.3% norfloxacin and 0.3% ciprofloxacin and their effect upon normal eyelid flora in 39 patients undergoing cataract surgery. Lid swabs were taken before and after six 1 hourly applications of single drops of ciprofloxacin or norfloxacin given before surgery. Aqueous humour was aspirated at surgery and antibiotic concentration assayed using high performance liquid chromatography. The mean aqueous humour concentrations were: ciprofloxacin 220 ng ml-1, norfloxacin 140 ng ml-1. Although this difference was not statistically significant (p = 0.112) the trend demonstrated may be relevant clinically, especially considering the greater activity of ciprofloxacin. Both coagulase negative staphylococcal (p = 0.004) and total bacterial (p = 0.019) lid counts dropped sixfold after ciprofloxacin treatment but the smaller reductions noted after norfloxacin application did not achieve statistical significance (p > 0.1). The reduction of external eye flora experienced with ciprofloxacin suggests that this may be a useful presurgical prophylactic agent.