Fiona Lees

Prophylaxis of postoperative endophthalmitis following cataract surgery: Results of the ESCRS multicenter study and identification of risk factors

PURPOSE: To identify risk factors and describe the effects of antibiotic prophylaxis on the incidence of postoperative endophthalmitis after cataract surgery based on analysis of the findings of the European Society of Cataract & Refractive Surgeons (ESCRS) multicenter study. SETTING: Twenty‐four ophthalmology units in Austria, Belgium, Germany, Italy, Poland, Portugal, Spain, Turkey, and the United Kingdom. METHODS: A prospective randomized partially masked multicenter cataract surgery study recruited 16 603 patients. The study was based on a 2 × 2 factorial design, with intracameral cefuroxime and topical perioperative levofloxacin factors resulting in 4 treatment groups. The comparison of case and non‐case data was performed using multivariable logistic regression analyses. Odds ratios (ORs) associated with treatment effects and other risk factors were estimated. RESULTS: Twenty‐nine patients presented with endophthalmitis, of whom 20 were classified as having proven infective endophthalmitis. The absence of an intracameral cefuroxime prophylactic regimen at 1 mg in 0.1 mL normal saline was associated with a 4.92‐fold increase (95% confidence interval [CI], 1.87‐12.9) in the risk for total postoperative endophthalmitis. In addition, the use of clear corneal incisions (CCIs) compared to scleral tunnels was associated with a 5.88‐fold increase (95% CI, 1.34‐25.9) in risk and the use of silicone intraocular lens (IOL) optic material compared to acrylic with a 3.13‐fold increase (95% CI, 1.47‐6.67). The presence of surgical complications increased the risk for total endophthalmitis 4.95‐fold (95% CI, 1.68‐14.6), and more experienced surgeons were more likely to be associated with endophthalmitis cases. When considering only proven infective endophthalmitis cases, the absence of cefuroxime and the use of silicone IOL optic material were significantly associated with an increased risk, and there was evidence that men were more predisposed to infection (OR, 2.70; 95% CI, 1.07‐6.8). CONCLUSIONS: Use of intracameral cefuroxime at the end of surgery reduced the occurrence of postoperative endophthalmitis. Additional risk factors associated with endophthalmitis after cataract surgery included CCIs and the use of silicone IOLs.

ESCRS study of prophylaxis of postoperative endophthalmitis after cataract surgery: Preliminary report of principal results from a European multicenter study.

PURPOSE: To report results in the European Society of Cataract & Refractive Surgeons (ESCRS) multicenter study of the prophylaxis of endophthalmitis after cataract surgery. SETTING: Twenty‐four ophthalmology units and eye clinics in Austria, Belgium, Germany, Italy, Poland, Portugal, Spain, Turkey, and the United Kingdom, with an administrative office in Ireland, coordinating center in England, and data management and statistical unit in Scotland. METHODS: This partially masked randomized placebo‐controlled multinational clinical study to evaluate prospectively the prophylactic effect of intracameral cefuroxime injection and/or perioperative levofloxacin eyedrops on the incidence of endophthalmitis after phacoemulsification cataract surgery began in September 2003 and was terminated early in January 2006. The study used random allocation of patients in a 2 × 2 factorial design. RESULTS: By the end of 2005, complete follow‐up records had been received for 13 698 study patients. Such a clear beneficial effect from the use of intracameral cefuroxime had been observed that it was agreed it would be unethical to continue the study and to wait for the completion of all follow‐up procedures before reporting this important result. If total reported cases of endophthalmitis are considered, the incidence rate observed in those treatment groups not receiving cefuroxime prophylaxis (23 cases in 6862 patients) was almost 5 times as high (odds ratio [OR], 4.59; 95% confidence interval [CI], 1.74‐12.08; P = .002) as that in the groups receiving this treatment (5 cases in 6836 patients). If only cases proved to be due to infection are considered, the rate was more than 5 times as high (OR, 5.32; 95% CI, 1.55‐18.26; P = .008) in the treatment groups not receiving cefuroxime. Although the use of perioperative levofloxacin eyedrops as prophylaxis was also associated with a reduction in the observed incidence rate of postoperative endophthalmitis, this effect was smaller and was not statistically significant, whether total reported cases or only cases proven to be due to infection are used in calculating the rates. As not all follow‐up procedures are complete, it is possible that further cases of endophthalmitis may be reported; however, it is not expected that this will alter the main conclusion. Nevertheless, it is anticipated that successful completion of follow‐up procedures in all patients will increase the total number in the study to approximately 16 000. CONCLUSION: Intracameral cefuroxime administered at the time of surgery significantly reduced the risk for developing endophthalmitis after cataract surgery.

ESCRS study of prophylaxis of postoperative endophthalmitis after cataract surgery: Case for a European multicenter study.

PURPOSE: To present the development and design of the European Society of Cataract & Refractive Surgeons multicenter study of the prevention of postsurgical infective endophthalmitis after phacoemulsification and to describe the process for its successful implementation and conduct. SETTING: Twenty‐four ophthalmology units and eye clinics in Austria, Belgium, Germany, Italy, Poland, Portugal, Spain, Turkey, and the United Kingdom, with an administrative office in Ireland, coordinating center in England, and data management and statistical unit in Scotland. METHODS: This partially masked randomized placebo‐controlled multinational clinical study was designed to evaluate prospectively the prophylactic effect of intracameral cefuroxime and/or perioperative topical levofloxacin on postoperative endophthalmitis after cataract surgery. Random allocation was based on a 2 × 2 factorial design that included participating centers as a class variable. Real‐time electronic data collection monitored study progress and provided weekly outcome tables, monthly recruitment summaries, and quarterly analytical reports for the studys Data Monitoring Committee, which evaluated the safety and efficacy by Internet‐based conferences. RESULTS: A 2‐year lead time was required to meet harmonized standards of clinical research in the European Union, obtain ministerial authorization in 3 countries, gain institutional approvals at 24 hospitals, and procure indemnity insurance for surgical centers. Informed consent instruments, designed to comply with national health policies, were translated into 8 languages. The use of information technology to collect study data enabled the organizers to evaluate individual eligibility at enrollment, adherence with study medications during and after surgery, and postoperative status during follow‐up. CONCLUSION: This international cooperative study provided the opportunity to estimate the current incidence of endophthalmitis after cataract surgery in Europe and determine whether 1 or both of 2 antimicrobial regimens reduces the risk for postsurgical intraocular infection.

The efficacy of emamectin benzoate against infestations of Lepeophtheirus salmonis on farmed Atlantic salmon (Salmo salar L) in Scotland, 2002-2006

Background Infestations of the parasitic copepod Lepeophtheirus salmonis, commonly referred to as sea lice, represent a major challenge to commercial salmon aquaculture. Dependence on a limited number of theraputants to control such infestations has led to concerns of reduced sensitivity in some sea lice populations. This study investigates trends in the efficacy of the in-feed treatment emamectin benzoate in Scotland, the active ingredient most widely used across all salmon producing regions. Methodology/Principal Findings Study data were drawn from over 50 commercial Atlantic salmon farms on the west coast of Scotland between 2002 and 2006. An epi-informatics approach was adopted whereby available farm records, descriptive epidemiological summaries and statistical linear modelling methods were used to identify factors that significantly affect sea lice abundance following treatment with emamectin benzoate (SLICE®, Schering Plough Animal Health). The results show that although sea lice infestations are reduced following the application of emamectin benzoate, not all treatments are effective. Specifically there is evidence of variation across geographical regions and a reduction in efficacy over time. Conclusions/Significance Reduced sensitivity and potential resistance to currently available medicines are constant threats to maintaining control of sea lice populations on Atlantic salmon farms. There is a need for on-going monitoring of emamectin benzoate treatment efficacy together with reasons for any apparent reduction in performance. In addition, strategic rotation of medicines should be encouraged and empirical evidence for the benefit of such strategies more fully evaluated.

Factors associated with changing efficacy of emamectin benzoate against infestations of Lepeophtheirus salmonis on Scottish salmon farms

The availability and use of medicines to control infestations of sea lice on Atlantic salmon, Salmosalar L., farms in Scotland has changed considerably in the last decade (Lees, Gettinby & Revie 2008b). Whereas hydrogen peroxide and organophosphate compounds were used widely throughout the 1990s and in the early 2000s, only two therapeutants have remained in common use since 2005: topical cypermethrin (Excis; Novartis Animal Health, Camberley, UK) and an oral formulation of emamectin benzoate (SLICE; Schering Plough Animal Health, Uxbridge, UK).

Clinical observations associated with proven and unproven cases in the ESCRS study of prophylaxis of postoperative endophthalmitis after cataract surgery

PURPOSE: To describe cases of postoperative endophthalmitis in the European Society of Cataract & Refractive Surgeons (ESCRS) study of the prophylaxis of endophthalmitis, compare characteristics of unproven cases and cases proven by culture or polymerase chain reaction, and compare the characteristics with those in other reported series. SETTING: Twenty‐four ophthalmology units in Austria, Belgium, Germany, Italy, Poland, Portugal, Spain, Turkey, and the United Kingdom. METHODS: Univariable and multivariable logistic regression models were used to analyze data for statistical association of signs and symptoms in cases with proven or unproven endophthalmitis. Specific data describing characteristics of the cases were compared between the 2 types of cases. RESULTS: Data from 29 endophthalmitis cases were analyzed. Swollen lids and pain were statistically associated with proven cases of endophthalmitis on univariable regression analysis. Multivariable analysis indicated that swollen lids and an opaque vitreous were associated with proven cases. Five cases of endophthalmitis occurred in the cefuroxime‐treated groups. No case of streptococcal infection occurred in the cefuroxime‐treated groups. However, cases of infection due to streptococci showed striking differences in visual acuity and were associated with earlier onset. Characteristics in the 29 cases parallel results in previous studies, such as the Endophthalmitis Vitrectomy Study, although the addition of a control group in the ESCRS study elicited additional findings. CONCLUSION: Swollen lids, pain, and an opaque vitreous were statistically associated with proven endophthalmitis cases in the ESCRS study.

Changes in epidemiological patterns of sea lice infestation on farmed Atlantic salmon, Salmo salar L., in Scotland between 1996 and 2006

Analyses of a unique database containing sea lice records over an 11 year period provide evidence of changing infestation patterns in Scotland. The data, collected from more than 50 commercial Atlantic salmon farms, indicate that both species of sea lice commonly found in Scotland, Lepeophtheirus salmonis and Caligus elongatus, have declined on farms over the past decade. Reductions for both species have been particularly marked since 2001 when more effective veterinary medicines became available. Treatment data were also available in the database and these show a growing trend towards the use of the in-feed medication emamectin benzoate (Slice), particularly in the first year of the salmon production cycle. However, this trend towards single product use has not been sustained in 2006, the latest year for which data are available. There is some evidence of region to region variation within Scotland with the Western Isles experiencing higher levels of infestation. However, compared to the levels observed between 1996 and 2000, all regions have benefited from reduced lice infestation, with the overall pattern showing a particular reduction in the second and third quarters of the second year of production.

Temporal and spatial variations in lice numbers on salmon farms in the Hardanger fjord 2004–06

The long and narrow Hardanger fjord in western Norway has a high density of salmon farms and has had severe salmon lice, Lepeophtheirus salmonis, problems. In the years 2004-06, salmon lice numbers were recorded in selected salmon farms in the fjord as part of a larger research project. Most farm sites participated in a strategic control programme and were deloused between November and January in each year. The aim of the programme was to achieve a mean abundance of <0.3 adult female lice at this time and to minimize the infection pressure on wild smolts in the spring. Dedicated teams carried out detailed counting of lice on farmed fish in April-September each year. Temperature conditions were fairly similar throughout the fjord and amongst years, but wide variations in salinities were observed. The two innermost zones, B and C, had the lowest lice mean abundances, whereas the outermost zones, D and E, consistently had more lice. General linear model analyses showed that differences in adult female lice abundance between the zones were associated with differing levels of salinity and emamectin benzoate treatments strategically administered. Mean fish weight was significantly positively correlated with mean abundance of adult female lice.

The use of prevalence as a measure of lice burden: a case study of Lepeophtheirus salmonis on Scottish Atlantic salmon, Salmo salar L., farms

This study investigates the benefits of using prevalence as a summary measure of sea lice infestation on farmed Atlantic salmon, Salmo salar L. Aspects such as sampling effort, the relationship between abundance and prevalence arising from the negative binomial distribution, and how this relationship can be used to indicate the degree of aggregation of lice on a site at a given time point are discussed. As a case study, data were drawn from over 50 commercial Atlantic salmon farms on the west coast of Scotland between 2002 and 2006. Descriptive statistics and formal analysis using a linear modelling technique identified significant variations in sea lice prevalence across year class, region and season. Supporting evidence of a functional relationship between prevalence and abundance of sea lice is provided, which is explained through the negative binomial distribution.