Raubzug der Parteien

Beitrag im Fernsehmagazin Panorama am 4.11.2010, 22.00 Uh

Meridional ocular magnification after cataract surgery with toric and non-toric intraocular lenses

Background Overall ocular magnification (OOM) and meridional ocular magnification (MOM) with consequent image distortions have been widely ignored in modern cataract surgery. The purpose of this study was to investigate OOM and MOM in a general situation with an astigmatic refracting surface. Methods From a large dataset containing biometric measurements (IOLMaster 700) of both eyes of 9734 patients prior to cataract surgery, the equivalent (PIOLeq) and cylindric power (PIOLcyl) were derived for the HofferQ, Haigis, and Castrop formulae for emmetropia. Based on the pseudophakic eye model, OOM and MOM were extracted using 4 × 4 matrix algebra for the corrected eye (with PIOLeq/PIOLcyl (scenario 1) or with PIOLeq and spectacle correction of the residual refractive cylinder (scenario 2) or with PIOLeq remaining the residual uncorrected refractive cylinder (blurry image) (scenario 3)). In each case, the relative image distortion of MOM/OOM was calculated in %. Results On average, PIOLeq/PIOLcyl was 20.73 ± 4.50 dpt/1.39 ± 1.09 dpt for HofferQ, 20.75 ± 4.23 dpt/1.29 ± 1.01 dpt for Haigis, and 20.63 ± 4.31 dpt/1.26 ± 0.98 dpt for Castrop formulae. Cylindric refraction for scenario 2 was 0.91 ± 0.70 dpt, 0.89 ± 0.69 dpt, and 0.89 ± 0.69 dpt, respectively. OOM/MOM (× 1000) was 16.56 ± 1.20/0.08 ± 0.07, 16.56 ± 1.20/0.18 ± 0.14, and 16.56 ± 1.20/0.08 ± 0.07 mm/mrad with HofferQ; 16.64 ± 1.16/0.07 ± 0.06, 16.64 ± 1.16/0.18 ± 0.14, and 16.64 ± 1.16/0.07 ± 0.06 mm/mrad with Haigis; and 16.72 ± 1.18/0.07 ± 0.05, 16.72 ± 1.18/0.18 ± 0.14, and 16.72 ± 1.18/0.07 ± 0.05 mm/mrad with Castrop formulae. Mean/95% quantile relative image distortion was 0.49/1.23%, 0.41/1.05%, and 0.40/0.98% for scenarios 1 and 3 and 1.09/2.71%, 1.07/2.66%, and 1.06/2.64% for scenario 2 with HofferQ, Haigis, and Castrop formulae. Conclusion Matrix representation of the pseudophakic eye allows for a simple and straightforward prediction of OOM and MOM of the pseudophakic eye after cataract surgery. OOM and MOM could be used for estimating monocular image distortions, or differences in overall or meridional magnifications between eyes

Effects of three intravitreal injections of aflibercept on the ocular circulation in eyes with age-related maculopathy

Aims: To investigate changes in ocular perfusion following three consecutive intravitreal injections with aflibercept for treatment of neovascular age-related macular degeneration (nAMD). Methods The study included 20 eyes from 20 Caucasian patients with unilateral nAMD and 20 fellow eyes. All nAMD eyes were treated with standard intravitreal injection of aflibercept (IVA;2 mg). Measurements of ocular perfusion at the optic nerve head (ONH) and the choroid were performed with laser speckle flowgraphy (LSFG). Measurements were conducted at baseline, 1 week after the first injection, at the time point of the second and third injection as well as 1 month after the third injection. Results In treated eyes, mean blur rate (the main output parameter of LSFG) in the ONH microvasculature and in the choroid was significantly reduced 1 week after the first IVA treatment. The effect persisted throughout the entire follow-up period (p<0.001). No change in ocular perfusion was observed in fellow eyes. Conclusions: IVA for treatment of nAMD leads to a reduction in perfusion of the ONH and the choroid in the treated eye with no apparent effect on the fellow eye

An invasive and a noninvasive approach for the automatic differentiation of obstructive and central hypopneas

The automatic differentiation of obstructive and central respiratory events is a major challenge in the diagnosis of sleep-disordered breathing. Esophageal pressure (Pes) measurement is the gold-standard method to identify these events. This study presents a new classifier that automatically differentiates obstructive and central hypopneas with the Pes signal and a new approach for an automatic noninvasive classifierwith nasal airflow. An overall of 28 patients underwent night polysomnography with Pes recording, and a total of 769 hypopneas were manually scored by human experts to create a gold-standard annotation set. Features were automatically extracted fromthe Pes signal to train and test the classifiers (discriminant analysis, support vector machines, and adaboost). After a significantly (p < 0.01) higher incidence of inspiratory flow limitation episodes in obstructive hypopneas was objectively, invasively assessed compared to central hypopneas, the feasibility of an automatic noninvasive classifier with features extracted from the airflow signal was demonstrated. The automatic invasive classifier achieved a mean sensitivity, specificity, and accuracy of 0.90 after a 100-fold cross validation. The automatic noninvasive feasibility study obtained similar hypopnea differentiation results as a manual noninvasive classification algorithm. Hence, both systems seem promising for the automatic differentiation of obstructive and central hypopneas.Peer ReviewedPostprint (published version

Semiautomated SD-OCT Measurements of Corneal Sublayer Thickness in Normal and Post-SMILE Eyes

Purpose:To test the reliability of a novel algorithm for measuring corneal epithelial thickness (ET) and stromal thickness of normal eyes and post-small incision lenticule extraction (SMILE) corneas with spectral-domain optical coherence tomography.Methods:In this prospective observational study, a customized semiautomated software algorithm was developed and applied to measure corneal ET and stromal thickness along the horizontal corneal meridian. Measurements were performed by 2 examiners in a randomized fashion on a sample of 40 eyes with previous SMILE for treatment of myopia and a control group composed of 40 normal eyes. The intrauser repeatability and interuser reproducibility were analyzed by calculating typical indices including the coefficient of variation and intraclass correlation coefficient. Corneal sublayer thickness profiles were compared between normal and post-SMILE eyes.Results:In both groups, coefficients of variation were 3.2% or lower and intraclass correlation coefficients were 0.929 or higher indicating excellent reliability of the measurement method. Central ET was on an average 6 m greater in post-SMILE corneas (58.8 5.4 m) compared with normal eyes (52.8 +/- 4.0 m), with P < 0.01. Also, there was greater interindividual variability in ET in post-SMILE corneas and their horizontal epithelial profile seemed to show a lenticular appearance.Conclusions:Highly favorable indices of measurement reliability were achieved for this novel method of measuring corneal sublayer pachymetry not only in normal eyes but also in eyes with previous SMILE. The corneal ET profile was significantly altered in post-SMILE eyes compared with normal corneas

Analysis of Biomechanical Response After Corneal Crosslinking with Different Fluence Levels in Porcine Corneas.

PURPOSE To evaluate corneal stiffening of porcine corneas induced by corneal crosslinking (CXL) with constant irradiance as a function of total fluence. METHODS Ninety corneas from freshly enucleated porcine eyes were divided into five groups of 18 eyes. Groups 1-4 underwent epi-off CXL using a dextran-based riboflavin solution and an irradiance of 18 mW/cm2, group 5 served as the control group. Groups 1 to 4 were treated with a total fluence of 20, 15, 10.8, and 5.4 J/cm2, respectively. Thereafter, biomechanical measurements were performed on 5 mm wide and 6 mm long strips using an uniaxial material tester. Pachymetry measurements were performed on each cornea. RESULTS At 10% strain, the stress was 76, 56, 52, and 31% higher in groups 1-4, respectively compared to the control group. The Young's modulus was 2.85 MPa for group 1, 2.53 MPa for group 2, 2.46 MPa for group 3, 2.12 MPa for group 4, and 1.62 MPa for the control group. The difference between groups 1 to 4 and the control group 5 were statistically significant (p = <0.001; p = <0.001; p = <0.001; p = 0.021). In addition, group 1 showed significantly more stiffening than group 4 (p = <0.001), no other significant differences were found. Pachymetry measurements revealed no statistically significant differences among the five groups. CONCLUSION Additional mechanical stiffening can be achieved by increasing the fluence of the CXL. There was no threshold detected up to 20 J/cm2. A higher fluence could compensate the weaker effect of accelerated or epi-on CXL procedures

Inklusionsbarometer Mobilität 2022

Die Kern-Ergebnisse des Inklusionsbarometer Mobilität: Derzeit gibt es noch zu viele Barrieren in den verschiedenen Bereichen. So zum Beispiel werden der zeitliche Aufwand sowie die Kosten für Mobilität von Menschen mit Beeinträchtigung meist höher empfunden als von Menschen ohne Beeinträchtigung. Mangelnde Zugänglichkeit und Verfügbarkeit sind für mobilitätseingeschränkte Personen ein noch größeres Problem als für andere Nutzer*innen. Auch das Thema Unsicherheiten und fehlende Unterstützung auf dem Weg von A nach B spielt bei Menschen mit Beeinträchtigung eine größere Rolle als bei Menschen ohne. Das Inklusionsbarometer Mobilität zeigt diese Barrieren auf und stellt fest: Es müssen neue Konzepte entwickelt werden, die Mobilität für Menschen mit und ohne Beeinträchtigung gleichwertig möglich und besser machen. Für die repräsentative Online-Befragung untersuchte die Aktion Mensch in Zusammenarbeit mit dem Marktforschungsinstitut Ipsos, einer Ko-Forschenden-Gruppe sowie Mobilitäts- und Inklusions-Expert*innen die Aussagen von 1.000 Menschen mit und 500 ohne Beeinträchtigung. In Sachen Teilhabe an Mobilität gibt es für Menschen mit Beeinträchtigung zwei Medaillen-Seiten: die gewünschte Teilhabe - und die tatsächliche. Nach einem partizipativen Ansatz, sprich unter Beteiligung von Menschen mit Beeinträchtigung, wurden Fragen zu sechs Dimensionen von Mobilität entwickelt: Verfügbarkeit, Zugänglichkeit, Zeit und Kosten, Soziale Aspekte, Nachhaltigkeit und Digitalisierung. Einige dieser Aspekte beurteilen Menschen mit Beeinträchtigung und solche ohne sehr ähnlich, andere signifikant unterschiedlich. Die Ergebnisse der sechs Dimensionen ergeben in unterschiedlicher Gewichtung den Gesamtindex des Inklusionsbarometers Mobilität. Neben klassischen Studien-Inhalten enthält die Publikation Mobilitätsportraits von vier Personen mit Beeinträchtigung sowie ausführliche Steckbriefe zu inklusiver Mobilität in den acht Metropolregionen Hamburg, Berlin, Ruhrgebiet, Düsseldorf, Köln, Frankfurt, Stuttgart und München. Außerdem gibt es Gastbeiträge von Olga Nevska (CEO von Telekom MobilitySolutions), Kilian Frey (Umweltbundesamt), Katja Diehl (Autorin zum Thema Verkehrswende) und Ottmar Miles-Paul (LIGA Selbstvertretung). Abgeleitet von den Ergebnissen der Umfrage im Hinblick auf die Mobilitätserfahrungen der Befragten sind am Ende der Studie Empfehlungen zusammengestellt, was zu tun ist um Mobilität so zu gestalten, dass alle an ihr teilhaben können

Impact of uncertainties in biometric parameters on intraocular lens power formula predicted refraction using a Monte‐Carlo simulation

Purpose: The purpose of this study was to investigate the uncertainty in the formula predicted refractive outcome REFU after cataract surgery resulting from measurement uncertainties in modern optical biometers using literature data for within‐subject standard deviation Sw. Methods: This Monte–Carlo simulation study used a large dataset containing 16 667 preoperative IOLMaster 700 biometric measurements. Based on literature Sw values, REFU was derived for both the Haigis and Castrop formulae using error propagation strategies. Using the Hoya Vivinex lens (IOL) as an example, REFU was calculated both with (WLT) and without (WoLT) consideration of IOL power labelling tolerances. Results: WoLT the median REFU was 0.10/0.12 dpt for the Haigis/Castrop formula, and WLT it was 0.13/0.15 dpt. WoLT REFU increased systematically for short eyes (or high power IOLs), and WLT this effect was even more pronounced because of increased labelling tolerances. WoLT the uncertainty in the measurement of the corneal front surface radius showed the largest contribution to REFU, especially in long eyes (and low power IOLs). WLT the IOL power uncertainty dominated in short eyes (or high power IOLs) and the uncertainty of the corneal front surface in long eyes (or low power IOLs). Conclusions: Compared with published data on the formula prediction error of refractive outcome after cataract surgery, the uncertainty of biometric measures seems to contribute with ⅓ to ½ to the entire standard deviation. REFU systematically increases with IOL power and decreases with axial length

Paracentral acute middle maculopathy and risk of cardiovascular disease, stroke, and death: a longitudinal study

PURPOSE: To evaluate the risk of acute cardiovascular events (CVE), including cardiovascular diseases, cerebrovascular diseases, and all-cause mortality in patients with paracentral acute middle maculopathy (PAMM). DESIGN: Retrospective cohort study METHODS: We studied 43 individuals with optical coherence tomography -documented PAMM attending Moorfields Eye Hospital between January 2014 and June 2021. We excluded patients with preceding (< 2 years) major adverse cardiac events. We stratified patients by age (<50 years & ≥50 years) and whether associated with retinal vascular diseases (RVD) or isolated (iPAMM). We assessed risk factors, clinical characteristics, and visual prognosis of the patients. CVE risk was estimated using Kaplan-Meier curves, the log-rank test, and Cox proportional hazards regression. RESULTS: In young patients with iPAMM patients (n=12), underlying predisposing factors included six (50%) sickle cell disease and five (41.6%) others, including breakthrough bleeding in pregnancy, migraine, genetic cardiomyopathy, amphetamine use; among those with PAMM+RVD (n=12) one (9%) had a vascular disorder, and four (44.4%) oral contraceptive use. In the older group of 20 patients, 15 (75%) had at least one coronary risk factor. During a median follow-up of 14 months (range 12-54), older subjects with iPAMM had a higher risk of developing CVE than those with PAMM+RVD (p<0.001). Notably, iPAMM displayed a significantly earlier peak in peri-PAMM CVE risk compared to PAMM+RVD (median: 1 month, range 1-40 months vs. 36 months, range 12-54 months). Relative to those with PAMM+RVD, risk of CVE was significantly higher in patients with iPAMM, adjusted for age and sex (hazard ratio: 6.37, 95% Confidence Interval 1.68-24.14, p=0.017). No young patients experienced adverse CVE. At baseline, older iPAMM patients mean best corrected visual acuity of 0.7 (0-1.8) LogMAR, which improved significantly to 0.2 (0-1.30) LogMAR at the latest visit (p=0.033). CONCLUSION: Young individuals with iPAMM have a higher prevalence of predisposing factors compared to those presenting with combined PAMM+RVD. Older patients with iPAMM had a higher risk of CVE than those with PAMM+RVD, especially in the peri-onset timeframe. This suggests the need for a prompt cardiovascular assessment to rule out systemic etiologies and optimize cardiovascular risk factors, in addition to ongoing ophthalmology input

Real time geotechnical field data acquistion using a distributed approach

A distributed geotechnical remote analysis of data system (Distributed G-RAD) can benefit both owners and contractors in providing better quality control and assurance on geotechnical projects. The Distributed G-RAD approach involves efficient data acquisition using PDAs with GPS capability, radio frequency identification (RFID) tags for labeling soil samples, laser scanning for measuring lift thickness and volumes of stockpiles and borrow pits. Spatial data storage is provided using a geographic information system (GIS). Portions of this system are already developed while other parts are still being considered. This paper also describes how RFID and laser scanning technologies can be used in the larger Distributed G-RAD system