With the use of an endoscopic, high-speed camera, vocal fold dynamics may be observed clinically during phonation. However, observation and subjective judgment alone may be insufficient for clinical ...diagnosis and documentation of improved vocal function, especially when the laryngeal disease lacks any clear morphological presentation. In this study, biomechanical parameters of the vocal folds are computed by adjusting the corresponding parameters of a three-dimensional model until the dynamics of both systems are similar. First, a mathematical optimization method is presented. Next, model parameters (such as pressure, tension and masses) are adjusted to reproduce vocal fold dynamics, and the deduced parameters are physiologically interpreted. Various combinations of global and local optimization techniques are attempted. Evaluation of the optimization procedure is performed using 50 synthetically generated data sets. The results show sufficient reliability, including 0.07 normalized error, 96% correlation, and 91% accuracy. The technique is also demonstrated on data from human hemilarynx experiments, in which a low normalized error (0.16) and high correlation (84%) values were achieved. In the future, this technique may be applied to clinical high-speed images, yielding objective measures with which to document improved vocal function of patients with voice disorders.
Simultaneous stereoscopic fundus photography is an important tool for classification and follow-up of glaucomatous optic neuropathy. The use of conventional film-based simultaneous stereoscopic ...fundus cameras is complicated and time-consuming due to film processing and the sensitivity of its mechanical components. Digital simultaneous stereoscopic fundus cameras are not available in Germany, since the existing ones are lacking the CE certificate. The authors realised a solution by transforming a conventional stereophotographic film-based fundus camera into a digital one. The analogue camera of the conventional stereophotographic device was replaced by a digital 36×24 mm full-frame complementary metal oxide (CMOS) camera.
This study aims at substituting the essential functions of photoreceptors in patients who are blind owing to untreatable forms of hereditary retinal degenerations. A microelectronic neuroprosthetic ...device, powered via transdermal inductive transmission, carrying 1500 independent microphotodiode-amplifier—electrode elements on a 9 mm 2 chip, was subretinally implanted in nine blind patients. Light perception (8/9), light localization (7/9), motion detection (5/9, angular speed up to 35 deg s −1 ), grating acuity measurement (6/9, up to 3.3 cycles per degree) and visual acuity measurement with Landolt C-rings (2/9) up to Snellen visual acuity of 20/546 (corresponding to decimal 0.037 or corresponding to 1.43 logMAR (minimum angle of resolution)) were restored via the subretinal implant. Additionally, the identification, localization and discrimination of objects improved significantly (n = 8; p < 0.05 for each subtest) in repeated tests over a nine-month period. Three subjects were able to read letters spontaneously and one subject was able to read letters after training in an alternative-force choice test. Five subjects reported implant-mediated visual perceptions in daily life within a field of 15° of visual angle. Control tests were performed each time with the implant's power source switched off. These data show that subretinal implants can restore visual functions that are useful for daily life.
Abstract
Purpose: One approach for restoring vision in end-stage hereditary retinal diseases is implantation of a subretinal microphotodiode array. We analyzed retinal fluorescein angiography ...findings of the implant area.
Methods: In this pilot study, patients (n = 11; 10 men, one woman; ages 45.2 ± 8.7 years), with visual acuity of light perception or worse resulting from a hereditary retinal degenerative disease, received active electronic subretinal visual implants. Implants were removed after 4 weeks (n = 7 subjects) or 4 months (n = 4 subjects). Following implantation, regular fluorescein angiography was performed. Regions of retinal capillary loss, microaneurysms, capillary alterations, neovascularization and leakage over the implant were scored at time points T1 (days 1-14), T2 (days 15-28) and T3 (months 3-4). Occurrence and changes of fluorescein angiographic phenomena are reported.
Results: In terms of the number of patients in whom retinal alterations were observed (compared to available images) the occurences of the angiographic phenomena (for time points T1, T2 and T3, respectively) were as follows: regions of capillary loss (five of seven, 10 of 11 and five of five patients), microaneurysms (0 of seven, two of 11 and three of five patients), calibre alterations of the capillaries (three of seven, eight of 11 and five of five patients), retinal neovascularization (one of seven, one of 11 and 0 of five) and leakage (three of seven, seven of 11 and four of five). The Friedman test revealed no significant changes in capillary loss, calibre alteration of the capillaries, neovascularization or leakage. Microaneurysms increased significantly (p = 0.037).
Conclusions: Subretinal visual implants lead to increased capillary microaneurysms, a possible compensatory mechanism following recovery of inner retinal activity. There were no significant changes in capillary loss, calibre alteration of the capillaries, retinal neovascularization and leakage at 4 months. Further study will determine whether and to what degree long-term vascular changes are affected by the surgical procedure, the implant itself and/or recovery of retinal neuronal activity.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
To determine normal values of the visual field (VF), corrected for age and reaction time (RT) for semiautomated kinetic perimetry (SKP) on the Octopus 900 perimeter, create a model describing the ...age-dependency of these values, and assess test-retest reliability for each isopter.
Eighty-six eyes of 86 ophthalmologically healthy subjects (age 11-79 years, 34 males, 52 females) underwent full-field kinetic perimetry with the Octopus 900 instrument. Stimulus size, luminance, velocity, meridional angle, subject age, and their interactions, were used to create a smooth multiple regression mathematical model (V/4e, III/4e, I/4e, I/3e, I/2e, I/1e, and I/1a isopters). Fourteen subjects (2 from each of 7 age groups) were evaluated on three separate sessions to assess test-retest reliability of the isopters. Reaction time (RT) was tested by presenting 12 designated RT-vectors between 10° and 20° within the seeing areas for the III/4e isopter (stimulus velocity, 3°/second). Four RT- vectors were presented at the nasal (0° or 180°), superotemporal (45°), and inferior (270°) meridians.
The model fit was excellent (
= 0.94). The test-retest variability was less than 5°, and the median decrease in this deviation attributed to aging, per decade, for all age groups and for all stimulus sizes was 0.8°. No significant learning effect was observed for any age group or isopter.
Age-corrected and RT-corrected normative threshold values for full-field kinetic perimetry can be adequately described by a smooth multiple linear regression mathematical model.
A description of the entire kinetic VF is useful for assessing a full characterization of VF sensitivity, determining function losses associated with ocular and neurologic diseases, and for providing a more comprehensive analysis of structure-function relationships.
Zusammenfassung
Hintergrund
Aufkommende Therapien führen zu wachsendem Interesse an hereditären Netzhauterkrankungen (engl. „inherited retinal diseases“ IRDs), einer heterogenen Gruppe seltener ...Erkrankungen, die potenziell zur Erblindung führen. Aktuell sind nur unzureichend systematische Studien zur Demografie und zum Management der IRDs in deutschen augenärztlichen Einrichtungen vorhanden.
Ziele der Arbeit
Charakterisierung der Versorgung von IRD-Patient*innen in Deutschland, Erfassung von Daten zur Diagnostik, zur systematischen Speicherung der Patient*innendaten und zur Weiterbildung in Ophthalmogenetik.
Methoden
Die anonyme Umfrage mittels Online-Fragebogen (SoSci Survey GmbH) wurde an alle deutschen Augenkliniken (Quelle: Deutsche Ophthalmologische Gesellschaft) und 3 IRD-Schwerpunktpraxen versandt. Der für die Umfrage entwickelte Katalog bestand aus 69 Fragen.
Ergebnisse
Die Antwortquote betrug 44,8 %. Fast alle Einrichtungen (93,6 %) gaben an, IRD-Patient*innen zu betreuen, jedoch unterscheiden sich universitäre und nichtuniversitäre Kliniken stark in der Patient*innenzahl. Datenbanken wurden in 60 % der universitären (UK) und 5,9 % der nichtuniversitären Kliniken (NUK) genutzt. Die Hälfte (53 %) der NUKs und 12 % der UKs gaben an, dass weniger als 20 % der betreuten Patient*innen eine molekulargenetische Diagnose erhielten. Die Antworten der Schwerpunktpraxen ähnelten denen der UKs. Patient*innen mit der mittels Voretigen Neparvovec therapierbaren
RPE65
-mutationsassoziierten IRD wurden in 9 UKs betreut.
Diskussion
Die Umfrage zeigt Defizite in der Versorgung von IRDs auf. Insbesondere war der Prozentsatz von Betroffenen mit bekanntem Genotyp zwischen UKs und NUKs sehr unterschiedlich. Hier sollten gerade wegen der aufkommenden Therapien Verbesserungen initiiert werden.
Zusammenfassung
Therapeutisches Drug-Monitoring (TDM) umfasst die Quantifizierung und die Interpretation von Serum- oder Plasmakonzentrationen von Arzneistoffen im Blut, um die Pharmakotherapie zu ...optimieren. TDM ist ein Werkzeug, mit dem sich die hohe interindividuelle Variabilität der Pharmakokinetik von Patienten identifizieren lässt und es ermöglicht somit eine personalisierte Pharmakotherapie. Im September 2017 veröffentlichte die Arbeitsgruppe Therapeutisches Drug-Monitoring der Arbeitsgemeinschaft für Neuropsychopharmakologie und Pharmakopsychiatrie (AGNP) ein Update der TDM-Konsensusleitlinien. In diesem Artikel sollen die wesentlichen Inhalte für die klinische Praxis in der Psychiatrie und Neurologie zusammengefasst werden.
In hereditary retinal diseases photoreceptors progressively degenerate, often causing blindness without therapy being available. Newly developed subretinal implants can substitute functions of ...photoreceptors. Retina implant extraocular surgical technique relies strongly on cochlear-implant know-how. However, a completely new surgical approach providing safe handling of the photosensor array had to be developed. The Retina Implant Alpha IMS consisting of a subretinal microphotodiode array and cable linked to a cochlear-implant-like ceramic housing was introduced via a retroauricular incision through a subperiosteal tunnel above the zygoma into the orbit using a specially designed trocar. Implant housing was fixed in a bony bed within a tight subperiosteal pocket in all patients. Primary outcomes were patient short term safety as well as effectiveness. Nine patients participated in the first part of the multicenter trial and received the subretinal visual implant in one eye. In all cases microphotodiode array pull-through procedure and stable positioning were possible without affecting the device function. No intraoperative complications were encountered. The minimally invasive suprazygomatic tunneling technique for the sensor unit as well as a subperiosteal pocket fixation of the implant housing provides a safe extraocular implantation approach of a subretinal device with a transcutaneous extracorporeal power supply.
Erratum zu:
Nervenarzt 2018
https://doi.org/10.1007/s00115-018-0643-9
Im Originalbeitrag ist Tab. 2 leider fehlerhaft. Für die Substanzen Carbamazepin und Valproat wurde im Originalbeitrag ein ...Empfehlungsgrad zur Anwendung des therapeutischen Drug-Monitorings (TDM) von 2 (
empfohlen
) angegeben. …
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