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- Master's Thesis (17) (remove)
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Institute
- Optik und Mechatronik (10)
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Das trockene Auge ist eine komplexe Erkrankung des vorderen Augenabschnitts. Es gibt eine Vielzahl von Ursachen, sowie eine Vielzahl an Therapiemöglichkeiten. Diese Arbeit befasst sich mit Benetzungsmitteln als Therapieform. Es existieren verschiedene Benetzungsmittel, die sowohl von Augenärzten, als auch von Optometristen und Optikern verabreicht werden. Es wird eine Übersicht über alle Benetzungsmittel erstellt, die in der Schweiz von Optometristen verabreicht werden können und ein Schema zur Anwendung je nach Diagnose entwickelt.
Demographische Veränderungen durch eine zunehmende Alterung der Gesellschaft und eine Zunahme an Erkrankungen wie der AMD, des Glaukoms und der diabetischen Retinopathie stellen ophthalmologische Versorgungs- und Vorsorgemaßnahmen in Deutschland vor immer größere Herausforderungen. Einen wesentlichen Beitrag zur Sicherung der Vorsorgemaßnahmen können in der Zukunft Optometristen leisten. Mit Hilfe modernster Technologien, wie dem Ultra-Widefield-cSLO (Optos Daytona, können auch bei kleinen Pupillendurchmessern 200° Aufnahmen vom Augenhintergrund erstellt werden.
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.
Purpose
The purpose of this study was to evaluate the validity of the iPad Aniseikonia Test for
measurement size lens-induced aniseikonia. The iPad Aniseikonia Test is a new
computer-based test designed for measuring aniseikonia in vertical direction. The iPad
Test uses red-green anaglyphs.
Methods
Aniseikonia was induced in 21 subjects by means of afocal size lenses. Resulting
aniseikonia was measured in vertical direction by the iPad Aniseikonia Test. The
measurement was performed in dark condition with appropriate correction of refractive
error. All subject were patients with normal vision with no anisometropia or other
ocular problem.
Results:
Afocal size lenses of known magnification were used to induce aniseikonia. 5
measurements were taken in each subject, ranging from zero to 7 % magnification.
When using the regression analysis, the slope of the fitted line significantly differs from
1. The average slope of regression line is 0,58.
Conclusions:
Only moderate accuracy was found for tested target size and orientation. In all cases the
iPad Aniseikonia Test underestimates the level of aniseikonia. However for gross
assessment of anisometropia in clinical practice it could be successfully used. Further
study with different target size should be addressed.
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.
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.
This research project is of particular importance since there is a lack of adequate data on pediatric eye and vision disorders in Russia, particularly in the Volga region. In the present study, we estimate the prevalence of vision disorders among school-aged children who participated in a vision screening program in Samara, Russia. The relationship between learning-related visual dysfunctions is explored in depth, such to illustrate the connection between vision and learning. Hence, a key feature in this study is the inclusion of binocular vision disorders among the conditions tested.
Purpose
The purpose of this study was to investigate the correlation of measured visual acuity
(VA) both static and dynamic obtained with static and dynamic measuring tests, as well
as, response time to visual stimulus and analysis of its influence on dynamic visual
acuity. The aim was to compare the results gathered for the three age groups and
analyze the possible differences.
Methods
The test groups consisted of 75 subjects between 10 and 60 years old, categorized in
three age groups. The measurements of static and dynamic visual acuity and reaction
time were conducted. The set of nine tests (five with radial magnification speed and four
simulating driving condition at 72 km/h and 130 km/h) was designed in order to measure
dynamic visual acuity and the set of two tests for reaction time measurement.
Results
Compared to static visual acuity in both tests, the results obtained with measurements
of dynamic visual acuity resulted in lower values depending on Landolt ring size and
magnification speed of animation. In average, the dynamic visual acuities in tests with
different magnification speeds were lower than static by 0.4 visual acuity units, or 31%
and the average of dynamic visual acuity after subtracting motoric component (reaction
time) was for 0.2 visual acuity worse than static or 15%. In the second test simulating
driving conditions at 72 km/h the average drop in dynamic visual acuity was 33% while
at 130 km/h average drop for younger and middle age groups was 37% and for older
group was 44% and after subtracting motor component values for 72 km/h speed
simulation average drop in visual acuity values was 23% for all three groups; for 130
km/h speed simulation younger and middle aged group average drop of visual acuity
was 20% and with older group it was 24%.
Conclusion
The tests used in this study were simple and fast and revealed significant difference
between static and dynamic visual acuity and influence of reaction time on dynamic
Nataša Vujko Muždalo Abstract
2
visual acuity values. It is hoped that this thesis will be a positive contribution in testing
and training of dynamic visual and sensory response skill with drivers, sportsmen and
people with visual-motor dysfunction.
Keywords: Dynamic visual acuity (DVA), static visual acuity (SVA), reaction time (RT),
motoric component, dynamic visual acuity test, reaction time test, radial increase in size
Novel myopia control spectacle lenses induce peripheral contrast reduction via optical diffusion. It is suggested, that the contrast reduction alters retinal processes in the low-level neural circuity, leading to an inhibition of eye growth. The purpose of this thesis is to evaluate the influence of full-field contrast reduction on low-level neural processing of the retina, described by the edge contrast sensitivity.
A good stereopsis (depth perception) is needed in everyday life, regardless whether a person is a professional driver or chef. Good estimation of distance, and of what is further and what closer, could mean the difference between a crushed and a whole car or between a bloody and a healthy finger. The main theme of this Master thesis is detect and quantify major factors in depth perception. Do the younger estimate the depth better than the older; do they have better depth perception with greater or smaller pupil distance; does depth perception depend on gender; what happens with stereopsis when vision is fogged by +0,5 and +1,0 D? These are the questions dealt with in this Master thesis.
To answer these questions measurements were made on 51 subjects (mean age 45,0 +/- 13,32 years) of whom 25 were women, mean age 45,5 +/-13,55 years (12 with PD<62 mm, mean and 13 with PD>66 mm) and 26 men, mean age 44,4 +/- 13,34 years (13 with PD<62 mm and, 13 with PD >66 mm). Each of these four groups was further divided by age (one in range 20 to 35 years and second in range 50 to 65 years).
The measurements were made with a few assumptions. The first assumption was that stereopsis is in direct correlation with visual acuity, the second assumption was that persons with bigger interpupillar distance have better stereopsis, and the third assumption was that with age the stereopsis ability decreases.
The measurements were done with modified Frisby–Davis test expanded from four geometrical shapes to twenty-five circles. The stereopsis was measured with full refractive correction at 4,5 and 3,0 meters. Later, stereopsis was measured with fogging with +0,5 and +1,0 D at the 4,5 and 3,0 meter distances.
Statistically there is no correlation (or very weak) between stereopsis and the visual acuity for whole group of 51 test persons, but if only young test persons are taken in consideration, the correlation becomes significant, r(20)=0,566, p=0,009 at 4,5 m and r(20)=0,456, p=0,043 at 3,0 m and that matches the assumption. Stereopsis is in no or weak positive correlation with pupil distance r(51)=0,059, p=0,679, which is in total contrast to the assumption. Stereopsis is in positive correlation with age at 4,5 meters measuring distance, r(51)=0,371, p=0,007, which corresponds to assumption. In addition, stereopsis is better in females than in males by 32,5%.
Based on the results it can be concluded that the stereopsis is in negative correlation with age, in positive correlation with visual acuity, females have better stereopsis than males and statistically, the correlation between stereopsis and pupil distance (PD) has not been proved. The most important conclusion is that the decreased visual acuity brings significant fall of stereopsis. A deficit in refraction of -0,50 D decreases stereo acuity by about 90% (nearly 2x) and a deficit of -1,0 D decreases stereo acuity by about 220% (about 3x).
Keywords: Stereopsis, stereo acuity, depth perception, pupil distance (PD), visual acuity (VA).