[Monte Carlo simulation of biometric effect sizes and their influence on the translational ratio of corneal astigmatism in the cylinders of toric intraocular lenses]. / Monte-Carlo-Simulation biometrischer Effektgrößen und deren Einfluss auf das Übersetzungsverhältnis des Hornhautastigmatismus in den Zylinder torischer Intraokularlinsen.

BACKGROUND AND OBJECTIVE: Toric intraocular lenses (IOL) provide a reliable and predictable option for permanent correction of corneal astigmatism. In order to determine the lens strength necessary for achieving the desired correction, the operator can either use the calculation mode implemented in the biometry device or the calculation service offered by the lens manufacturer; however, in many cases a classical lens calculation from biometric data is not carried out but only a simplified estimation, which translates the corneal astigmatism into the torus of the toric IOL. This translational ratio, which is mostly used as an average standard value, can however show a substantial range of variation, so that in a worst case scenario an undercorrection of the refractive cylinder of up to 12.5 % or an overcorrection of up to 17 % can result. The purpose of this study was to elaborate the biometric effect sizes which determine the relationship between the corneal astigmatism to be corrected and the torus necessary for a full correction of an IOL. METHODS: A total of 16,744 datasets were extracted from the IOLCon web platform and initially the axial position of the IOL implant was derived independent of a formula, based on the preoperative biometric values and the postoperative spherical equivalent. Subsequently, based on a ray propagation strategy for spherocylindrical vergences, the corresponding refractive value of a full correcting toric IOL was calculated. The translational relationship as a ratio between lens toricity and corneal astigmatism was analyzed for potential biometric effect sizes with a Monte Carlo simulation. RESULTS: The Monte Carlo simulation showed that the ratio of lens toricity to corneal astigmatism cannot be assumed as being constant. The analyzed data revealed an average translational ratio of 1.3938 ± 0.0595 (median 1.3921) with a range from 1.2131 to 1.5974. The axial position of the IOL was found to have the greatest influence, whereby the more posterior the lens position the higher the ratio. Due to the correlation of axial eye length and axial lens position, the eye length can be assumed to be an indirect effect size. The corneal equivalent refractive strength and the corneal astigmatism have no noteworthy effect on the translational ratio. CONCLUSION: Many calculation tools on the market simplify toric IOL power calculation by assuming a constant ratio of lens toricity to corneal astigmatism; however, the present simulation study showed that such a simplification can lead to clearly incorrect results. Accordingly, an individual calculation of IOL toricity based on biometric parameters (e.g. based on vergence propagation matrices or full aperture ray tracing) is recommended.

Potential formation of PCDD/Fs in triclosan wastewater treatment: An overall toxicity assessment under a life cycle approach.

Wastewater may contain a diverse group of unregulated pollutants known as emerging pollutants, such as pharmaceuticals and personal care products (PPCPs). Triclosan (TCS) is a personal care product widely used as an antiseptic or preservative in cosmetics, hand wash, toothpaste and deodorant soaps. Advanced oxidation processes (AOPs) have been used as effective and alternative treatments for complex wastewater. However, an important criterion for the assessment of AOPs and their operation conditions could be the potential formation of new toxic secondary products, such as polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), especially when emerging pollutants are present in the media. If these are omitted from environmental management studies, the real environmental impacts of a WWTPs (wastewater treatment plants) may be underestimated. Consequently, the current study aims to evaluate the environmental impacts derived from electrooxidation (EOX), one of the most effective oxidation technologies, of emerging pollutants using Life Cycle Assessment. The analyses were performed for the treatment of effluents containing TCS, firstly without considering the formation of PCDD/Fs and, thereafter, considering the effects of these compounds. Total toxicity, calculated through different methods and corresponding impact factors, were evaluated for each stage of the process when different electrolytes are used, including PCDD/Fs formation. Finally, a sensitivity analysis was carried out to study i) the effect of the TCS initial concentration on the environmental impacts associated to ecotoxicity for the different life cycle methods and ii) the influence of changing the organic pollutant on PCDD/Fs formation employing 2-chlorophenol (2-CP). As a result, LCIA methods demonstrate that they are not fully adapted to the computation of PCDD/Fs in the water compartment, since only 2,3,7,8-tetraclorodibenzo-p-dioxina (2,3,7,8-TCDD) is present as a substance in the impact categories assessed, ignoring the remaining list of PCDD/Fs.

[Simulation training as part of clinical risk management : A health economic view]. / Simulationstraining als Teil des klinischen Risikomanagements : Eine gesundheitsökonomische Betrachtung.

Working in anesthesiology is characterized by a complex environment in which effective teamwork with different disciplines as well as other professions (e. g. nursing staff and surgical assistants) is crucial. Clinical risk management includes all steps to prevent incidents and patient harm. An example for this is simulation training based on crisis resource management (CRM). This training course focuses on teaching non-medical skills using simulation manikins in order to enable employees to maintain patient safety under the adverse, ever-changing and unfamiliar conditions of a medical emergency. In detail, this involves skills, such as situation awareness, teamwork, decision making, task management and communication, whereby all elements must be taken equally into account to be effective in terms of CRM. A sustainable training aims to build up, promote and permanently establish a mindset within the team. Positive effects of these could be demonstrated for long-term training that addressed the entire patient care team and that was implemented along with various other patient safety measures. In addition, other positive aspects of simulation training, such as stronger employee retention or more effective task management in critical situations are described; however, hospitals are often found to have difficulties in financing these training sessions. This article shows possible health economic considerations in the discussion about financing CRM-based simulation training. Cost-benefit and cost-effectiveness analyses are difficult to perform. They require an individual planning. Regardless of this, simulation training enables participants to experience (simulation) and reflect their own actions in critical situations (debriefing). With the help of specially trained CRM instructors, deviations from expected behavior can be detected. This non-conformity can be used as a starting point for the establishment and further development of patient safety by a structural analysis of possible failures within the system. The decision to finance CRM-based simulation training remains a fundamental decision of the management of the respective hospital. In the near future, pressure from liability insurers to prevent incidents might increase. The inclusion of CRM-based simulation training as an integral component of clinical risk management could provide key benefits in contract negotiation.

[Assessment of chronic obstructive eustachian tube dysfunction : Evaluation of the German version of the Eustachian Tube Dysfunction Questionnaire]. / Beurteilung der chronisch-obstruktiven Tubenfunktionsstörung : Evaluation des "Eustachian Tube Dysfunction Questionnaire" in der deutschen Übersetzung.

BACKGROUND: Eustachian tube dysfunction can cause middle ear diseases and impair quality of life. Sufficient diagnostic tools for chronic obstructive eustachian tube dysfunction are lacking and not reliable enough. PATIENTS AND METHODS: The Eustachian Tube Dysfunction Questionnaire (ETDQ-7) was published by McCoul et al. in 2012 as an instrument to evaluate eustachian tube function. They demonstrated the reliability und validity of their questionnaire. The cut-off point for the diagnosis of eustachian tube dysfunction is ≥ 14.5 at 100 % sensitivity and 100 % specificity. We translated the ETDQ-7 into German and used it on 100 healthy subjects and 43 patients with chronic obstructive eustachian tube dysfunction. RESULTS: The results in the English questionnaire were confirmed by our examinations with the German version of the questionnaire. The mean ETDQ-7 score was 8.67 in the healthy subjects and 24.7 in the patients with chronic obstructive eustachian tube dysfunction. The area under the curve in ROC analysis was 98.8 % (p < 0.0001). CONCLUSION: We recommend the ETDQ-7 as an addition to patient history in the examination of eustachian tube dysfunction. It may as well be valuable in follow-up examinations to monitor treatment success.

[10 years of observation by public health offices in Baden-Württemberg--assessment of human biomonitoring for mercury due to dental amalgam fillings and other sources]. / 10 Jahre Beobachtungsgesundheitsämter in Baden-Württemberg--Beurteilung der Human-Biomonitoring-Untersuchungen bezüglich der Quecksilber-Belastung durch Amalgamfüllungen und andere Quellen.

Since 1992, in Baden-Württemberg, ten-year old children have been surveyed in the project "Sentinel Health Departments" to study their exposure to environmental pollutants and possible health effects. In the four study areas 1200 children have been investigated every year initially, since 1996 every second year. The data for mercury in body fluids are reported here. The decrease in the body burden of mercury as a result of the declining usage of dental amalgam fillings, was been verified. In 1992/93, of all the children who had been surveyed, the 95 percentile for the body burden of mercury was 3.1 microg/l and in 2000/01 1.35 microg/l. Also to be discussed is the reason why mercury-based cosmetic ointments seriously exceed the HBM-II-intervention-value. Because of using these ointments, concentrations of mercury in urine up to 1400 microg/l were found. A study within the project "Sentinel Health Departments" compared the concentrations of mercury in the urine of adults with those in blood and salvia. The results support the opinion that mercury in urine is appropriate for estimating the mercury uptake from dental amalgam fillings. It can be assumed that these results reflect the situation in the entire Federal Republic of Germany. The ten years' experience confirms that the concept of the "Sentinel Health Departments" is excellently suited to obtain data relevant for environmental health of children. Environmental health protection and the essential gathering of data for future health observation in Baden-Württemberg.

[Diagnostic guidelines for adrenal gland nodules: typing, assessment of biological potential and prognosis, molecular pathogenesis]. / Diagnostische Leitlinien bei Knoten in der Nebenniere: Typisierung, Dignitäts- und Prognoseerfassung, molekulare Pathogenese.

The aim of morphological tumour diagnosis is to answer clinical questions on type, biological potential, prognosis and aetiology of individual neoplasms. The limitations and perspectives of different methods used in the diagnosis of adrenal tumours, ranging from histology to molecular genetic DNA analyses, are described. When surgical specimens from adrenal neoplasms cannot be typed on the basis of histology and/or with clinica data (e.g. endocrine symptoms and history) as adrenocortical tumours, phaeochromocytomas or metastases to the adrenal, immunohistological investigations with a panel of different antibodies are necessary. After identification of the tissue derivation of an individual adrenal tumour, its biological potential must be assessed. Among adrenocortical neoplasms, adenomas and carcinomas can be distinguished by evaluation of various histological parameters (including structural features and signs of invasion) according to defined algorithms. In addition, conventional histology (by estimation of mitotic activity) allows the discrimination of tumours with especially high malignant potential from other adrenocortical carcinomas. In contrast, among adrenomedullary tumours even the combined use of histological, immunohistological and DNA cytophotometric techniques only allows the definition of risk groups (benign versus suggestive of malignancy), while reliable recognition of an individual malignant phaeochromocytoma is so far impossible. The question as to whether a particular phaeochromocytoma represents a sporadic tumour or a neoplasm inherited as one feature of a defined syndrome cannot be answered with the above methods, but only by the application of molecular genetic techniques.

Clinical assessment of Holo-Or trifocal diffractive contact lens.

PURPOSE: To evaluate the objective and subjective performance of the Holo-Or multifocal contact lens, a new rigid gas permeable (RGP) trifocal diffractive contact lens. METHODS: Eleven experienced and two non-experienced RGP contact lens wearers participated in the study. Eleven patients were presbyopic (age range: 40-57 years) and two were aphakic (ages: 12 and 14 years). Each patient was evaluated by comparing best spectacle correction to Holo-Or multifocal contact lens correction, using the following tests of visual function: visual acuity at 6 m, 80 cm, and 40 cm; contrast sensitivity at near and distance; and depth of focus. RESULTS: No significant differences were found between best spectacle correction and the Holo-Or contact lenses. When using the contact lenses, there was an improvement in depth of focus and a small reduction in contrast sensitivity compared with best spectacle correction. Overall satisfaction and comfort was good to excellent in ten of thirteen patients. CONCLUSIONS: Holo-Or trifocal diffractive contact lenses are a satisfactory means of optical correction for patients with presbyopia or accommodative problems.

Objective and subjective assessment of a new diffractive trifocal contact lens.

The purpose of this study was to test the objective and subjective performance of the Holo-Or Rigid Gas Permeable (RGP) Multifocal Contact Lens (MFCL), a new trifocal diffractive contact lens. Eleven experienced and two nonexperienced rigid gas permeable contact lens wearers participated in the study. Eleven patients were presbyopic (age 40-57) and two were aphakic (age 12 and 14). All patients were tested both with their best correction for distance and near and trifocal diffractive contact lenses. The follow-up period was 3-8 months. Subjective opinion was also assessed. Statistical analysis was performed using Student's t-test. We did not find any significant difference in visual acuity, measured at 6 m, 80 cm, and 40 cm, between best correction and Holo-Or diffractive contact lenses. Depth of focus improved to a statistically significant extent when using trifocal contact lenses. A small reduction in contrast sensitivity was observed when the patients used multifocal contact lenses. Overall satisfaction and comfort was good to excellent in 10 out of 13 patients. Two additional patients who used a bifocal model of the same contact lens design showed similar results. Holo-Or Trifocal Diffractive Contact Lenses are a satisfactory means of optical correction for patients with presbyopia or accommodative problems.