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Eine detaillierte Auswertung des Corneo-Skleral-Profils ist für die Anpassung von weichen Kontaktlinsen und Sklerallinsen von besonderer Relevanz. Das Ziel dieser Studie ist es, das Profil der limbalen Sklera anhand des Zusatzmoduls CSP-Report der OCULUS Pentacam® zu beschreiben. Hierbei soll überprüft werden, ob der CSP-Report Ergebnisse bisheriger Studien bestätigt und somit zukünftig zur Simulation von Sklerallinsen verwendet werden kann.
The direct ophthalmoscope is a retinal screening tool that has been in existence and development for more than 150 years, yet, the rapid influence of technological evolution in screening tools, has left the direct ophthalmoscope untouched. The main purpose of this master thesis is to determine if the direct ophthalmoscope has reached its maximum potential of development and, additionally, to determine if a further development, including a more electronic input, would be feasible.
Eine detaillierte Auswertung des Corneo-Skleral-Profils ist für die Anpassung von weichen Kontaktlinsen und Sklerallinsen von besonderer Relevanz. Das Ziel dieser Studie ist es, das Profil der limbalen Sklera anhand des Zusatzmoduls CSP-Report der OCULUS Pentacam® zu beschreiben. Hierbei soll überprüft werden, ob der CSP-Report Ergebnisse bisheriger Studien bestätigt und somit zukünftig zur Simulation von Sklerallinsen verwendet werden kann.
The increasing prevalence of myopia throughout the industrialized world in recent decades has caused costs and problems for the eye health. Changed lifestyle and behavior are the main causes. For the pathogenesis of myopia, the amount of time spent outdoor and near activities play an important role. Various options for the treatment of myopia have been described as effective in the literature. Normal single vision glasses and contact lenses can only provide clear vision, but do not reduce myopia progression. Orthokeratology shows a slowing of axial growth, but has an increased risk of infectious keratitis. Low-dose atropine (0.01%) is currently the best pharmacological option. It proved safe, effective and showed the least rebound effect with negligible side effects. Other options for the treatment of myopia include special glasses, behavioral changes and prolonged outdoor exposure (to prevent the onset of myopia), as well as other methods. An increasingly important myopia management option is multifocal contact lenses, that provide a peripheral treatment zone producing myopic defocus. Such myopia control lenses are available as customized or as daily or monthly lenses. Children benefit from wearing contact lenses more than just having refractive error correction and myopia control, they have a better self-esteem and improved quality of life. The numerous findings on the safety and efficacy of soft multifocal distance center contact lenses in children to reduce the progression of myopia suggest that this modality should be considered as a main treatment option. Less, but similar to orthokeratology, when wearing soft lenses there is a risk of developing potentially serious complications such as microbial keratitis. The introduction of child-appropriate risk minimization strategies, and patient and parent education with regular monitoring is essential and leads to successful contact lens wear. This literature review summarized the actual knowledge about myopia management, prevalence, etiology and the visual and healthy consequences of myopia.
The three currently most important strategies for slowing the progression of myopia are soft multifocal distance center contact lenses, Orthokeratology and low-dose atropine ophthalmic drops.
Fragestellung: Ist es sinnvoll im Kindesalter restriktiv einen UV-Schutz für die Augen anzuwenden, obwohl UV-Strahlung eine schützende Wirkung für das Entstehen einer Myopie hat?
Einleitung: Die Myopie ist eine typischerweise durch Längenwachstum des Augapfels verursachte Fehlsichtigkeit mit stark steigender Prävalenz in den letzten Jahrzenten. UV-Strahlung hat auf die Haut und die Augen eine Vielzahl negativer Auswirkungen. Nebst der akuten Photokeratitis sind Pinguecula, Pterygium, Plattenepithelneoplasie, Katarakt, AMD und maligne Melanome chronische Veränderungen. Andererseits bremst UV-Strahlung das Fortschreiten des Augenlängenwachstums.
Modellrechnung: Mittels dem evidenzbasierten Modellrechner kann das Risiko einer Myopie und deren Stärke anhand des Jahrgangs, der Sonnenschutzanwendung, der familiären Prädisposition, der Zeit im Freien und des Bildungsgrades berechnet werden. Gelegentlich angewandter Sonnenschutz hat gegenüber häufig angewandtem Sonnenschutz einen Schutzfaktor für die Myopieentstehung von 1.03. Das grösste Risiko einer Myopie kommt von der familiären Prädisposition.
Diskussion: Zeit im Freien hat einen grossen hemmenden Effekt auf die Myopie, Sonnenschutzanwendung nur einen leicht Fördernden. Zudem hat Sonnenschutz einen stark hemmenden Effekt auf UV-bedingte Augen- und Hauterkrankungen. Auf Sonnenschutz der Augen zu verzichten, um eine Myopie zu verhindern oder im Fortschreiten zu bremsen, scheint unvernünftig.
Red Teaming
(2019)
Zu Beginn der Arbeit wurden die theoretischen Grundlagen zu Penetrationstest, Audit und Red Teaming beschrieben. In den rechtlichen Rahmenbedingungen wurden betroffene Gesetze unter die Lupe genommen.
Anschließend wurde eine Marktforschung bestehend aus einer Primär- und einer Sekundärmarkforschung durchgeführt. Die Sekundärforschung beschreibt die Angebote und Dienstleister, die auf dem Markt Red Teaming anbieten. Daraus wurden Unternehmen aus dem DACH-Raum für die Interviews der Primärforschung ausgewählt.
Das Red Team muss ein vorher definiertes Ziel erreichen. Das Red Team führt in Abstimmung mit dem White Team Angriffe durch, die technische, physische und menschliche Komponenten betreffen können. Welche Komponenten verwendet werden, unterscheidet sich nach Projekt und Dienstleister. Das Blue Team hat die Aufgabe, die Angriffe zu erkennen und darauf zu reagieren.
Mit dem gesammelten theoretischen Wissen und den Interviews wurden die Methoden verglichen und eine Methodik zur Einordnung erstellt. Das Red Teaming, Penetrationstests und Audits sind für unterschiedliche Situationen nützlich. Um die Auswahl zu erleichtern, ist es sinnvoll, die Ziele zu definieren, die mit dem Test erreicht werden sollen.
Als dritter Indikator ist der Scope hilfreich, da ein Penetrationstest eine technische Prüfung darstellt und beim Audit oder Red Teaming oftmals eine ganzheitliche Betrachtung der Organisation erfolgt.
Im letzten Abschnitt wird eine praktikable Methode zur Durchführung von Red Teaming beschrieben. Hierzu wurden Thesen auf Grundlage des gesammelten Wissens aufgestellt.
Die Arbeit endet mit einem Fazit und den Zukunftsaussichten von Red Teaming.
Purpose: Recent studies found a reduction of myopia progression with multifocal contact lenses, however, with yet unclear mechanism. This raises the hypothesis that the addition zones of the multifocal contact lenses induce myopic defocus on the retina, which consequentially leads to choroidal thickening and therefore inhibited eye growth. We tested the effect of the optical design of multifocal contact lenses on choroidal thickness.
Methods: 18 myopic students wore four different contact lenses ((1) single-vision lens corrected for distance, (2) single-vision lens with +2.50 D full-field defocus, (3) “Multifocal center-distance” design, addition +2.50 D, (4) “Multifocal center-near” design, addition +2.50 D) for each 30 minutes on their right eye. Automated analysis of the macular choroidal thickness, vitreous chamber depth and eccentric photorefraction were performed before and after each contact lens.
Results: Choroidal thickness and vitreous chamber depth showed no significant differences to baseline with none of the contact lenses. Choroidal thickness increased the most with the “Multifocal center-distance” and the full-field defocus lens, followed by the “Multifocal center-near” and the single-vision contact lens (+2.1 ± 11.1 μm, +2.0 ± 11.1 μm, +1.6 ± 11.3 μm, +0.9 ± 11.2 μm, respectively). The “Multifocal center-distance” design showed an overall more myopic refractive profile than the other lenses. Changes of vitreous chamber depth occurred in anti-phase to these of choroidal thickness.
Conclusion: Multifocal contact lenses have no significant influence on choroidal thickness and after short-term wear. Therefore, it is assumed that it is not the main contributor to the protective effect of multifocal contact lenses in myopia control.
Purpose
Automated scanpath comparison metrics should deliver an objective method to
evaluate the similarity of scanpaths. The aim of this thesis is an evaluation of
seven existing scanpath comparison metrics in static and dynamic tasks in order
to provide a guidline that helps to decide which algorithm has to be chosen for a
special kind of task.
Methods
The applicability of the algorithms for a static, visual search task and a dynamic,
interactive video game task as well as their constraints and limitations were tested.
Therefore, binocular gaze data were recorded by using the eye tracking system The
Eye Tribe (The Eye Tribe ApS, Copenhagen/ Denmark). Objective task performance
measures from 21 subjects were used in order to create scanpath groupings
for which a relevant effect of dissimilarity was to be expected. Objective task performance
measures such as task performance time were statistically evaluated and
compared to the results gained by the comparison metrics.
Results
Four of the algorithms being used successfully identified differences for static and
dynamic tasks: MultiMatch, iComp, SubsMatch and the Hidden Markov Model.
ScanMatch was very sensitive for the static task but not applicable to the dynamic
task whereas FuncSim was suitable for dynamic but not for static tasks. Eyenalysis
failed to detect any effect.
Conclusion
The applicability of scanpath comparison metrics depends on the state of the task,
respectively on the kind of experimental set up. In future, the application area for
eye tracking will expand and an improvement of automated scanpath comparison
metrics is therefore required.
Purpose: Although the frequency in which practitioners are fitting scleral
contact lenses is increasing, the recommendation for proper tear layer depth
(thickness) varies amongst experts. The main goal of this paper is to clinically
verify the effect of varying tear layer depths on induced corneal edema during
lens wear.
Methods: Ten subjects with healthy eyes were fitted with scleral lenses on their
right eye. Each of them was fit with two different lenses: one with an apical
clearance of 200 μm and another with an apical clearance of 600 μm. They wore
the lenses for 8 hours on two different days, with at least a one week wash-out
period. Lenses were applied at 8 a.m. on each of the testing days. Pachymetry
measurements were taken one day prior to lens wear at 4 p.m., on the day of
wear prior to lens application, and after removal of the lenses at 4 p.m.
Measurements were collected using both the Pentacam® HR Corneal
Tomographer, as well as the Visante Anterior Segment Optical Coherence
Tomographer (OCT). The apical clearance was measured using the
Visante OCT at two intervals during the test day: immediately after application of
the lens and immediately prior to the removal of the lens.
Results: In this study, there was found to be no significant difference in corneal
edematous response during lens wear between the two test groups. The study
shows that the eyes with the lenses have a statistically significantly thicker
cornea compared to the non-lens-wearing eye after wearing either lens for 8
hours, lying within clinically and physiologically acceptable limits.
Conclusion: Our clinical results do not correlate with current theoretical
calculations, which predict a greater amount of corneal swelling with increasing
tear layer thickness. It has to be evaluated if the effect on corneal edema
changes with longer wearing periods, larger samples or other influences.
Key words: scleral (contact) lens, corneal edema, pachymetry, tear layer
thickness, vaulting, apical clearance
Abstract
1.1 Purpose
The purpose of this study is to prescribe follicular-like conjunctivitis associated with Siliconhydrogels
(FoCoSi) in silicone hydrogel contact lens wearers as a novel subtype of
the well prescribed contact lens induced papillary conjunctivitis (CLPC).
1.2 Methods
1211 patients who wore silicon hydrogels were included in this prospective, nonrandomised,
single center study. Subjective symptoms and clinical signs were evaluated
for daily wear (DW) and continuous wear (CW) populations for several (Lotrafilcon A,
Lotrafilcon B, Senofilcon A, Galyfilcon A) silicon hydrogel lens types. CCLRU and other
specifically developed grading scale were utilized for evaluation. Grading of 2 and above
was rated as clinically significant. Statistical evaluation was performed for eyes rather
than subjects.
1.3 Results
The clinical presentation of FoCoSi could be confirmed and showed an incidence of
3.8%. Lotrafilcon A followed by Senofilcon A on a CW modality presented, with a risk
ratio of 2.49 and 1.53 respectively, the highest affinity for developing FoCoSi. Fluorescein
positive spots showed the closest correlation with subjective symptoms reported
by patients and divided FoCoSi into an active and dormant form. Besides Protein, Lipid
deposition on the contact lens surface and air pollution like Ozone or fine and ultrafine
particles seems to be important factors in developing FoCoSi, whereas mechanical irritation
played a minor role.
1.4 Conclusion
FoCoSi is a novel and relevant subtype of CLPC. Further studies should be performed
to validate these findings and clear up several questions about the aetiology of FoCoSi
and CLPC.
Keywords: Giant papillary conjunctivitis (GPC), contact lens-induced papillary conjunctivitis
(CLPC), follicular-like conjunctivitis associated with siliconhydrogels (FoCoSi)