Post-graduate theses
Current Record: 4753 of 6563
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| Identifier |
000351982 |
| Title |
Ανάπτυξη και κατασκευή συμβολόμετρου προβολής αμφιβληστροειδικών κροσσών, για την παράκαμψη των οπτικών στοιχείων του οφθαλμού |
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Author
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Παπαδιαμάντης, Αναστάσιος
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Thesis advisor
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Γκίνης, Χαρίλαος
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Reviewer
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Τσιλιμπάρης, Μιλτιάδης
Παπάζογλου, Δημήτρης
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| Abstract |
Purpose: Visual perception begins on the retina. The light stimulus is captured from the photoreceptors (rod, cones) and converted to electrical signal. With the help of bipolar and ganglion cells the signal is driven to the optic nerve and the brain (LGN, V1, V2) for further processing.
Retina is the light sensitive part of the human eye. Correct and thorough testing is essential for many reasons. Main one is that retina is considered to be part of the central nervous sytem.
Purpose of this project is to build an instrument that projects fringes on the retina that can bypass the eye’s optics. These fringes will be of varying spatial frequency and contrast. More specific contrast can be altered without changing the average retinal luminance. Using this device can be very helpful for studies concerning the retina.
Methods: During the experimental procedure, a Michelson interferometer was built. The laboratory, where the procedure took place, was offered from V. E. I. C. and based on F. O. R. T. H. grounds. First step was to determine the most suitable, for the occasion, type of interferometer. Then building and grading of the device followed. Grading had to be made for the fringes’ spatial frequency and contrast.
After the device was constructed, contrast sensitivity measurements were made in order to determine whether the interferometer was working correctly or not. These measurements were made on patients with normal retinas, but had high refractive errors.
Results: The results were really satisfactory. Fringes were created for a wide range of spatial frequencies and contrasts. Taking into account the small size of the device, which makes it easy to move and use, the experimental procedure was successful.
At the same time the measurements’ results were also satisfactory. There was, in fact, agreement between present results and other from older and similar research projects.
Conclusions: The Michelson interferometer that was built can be used for either research or clinical purposes. It’s important though certain constructive improvements to be made. These improvements refer to the optic elements of the device. This way a wider zone of spatial frequencies can be attained. At the same time, necessary software is needed in order to make the device fully automated, something that will dramatically reduce the examination time.
After all these improvements the interferometer will be ready for visual acuity measurements and studies concerning spatial vision and the optic nerve. In fact using this device in patients with cataract can be extremely interesting.
This is because older people tend to develop cataract. With this device visual acuity measurement, prior to surgical removal, is possible. This way the benefits from the cataract removal, regarding the patient’s visual acuity, can be determined. This is because, due to age, certain retinal diseases can be also present, reducing visual acuity of the patient.
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| Physical description |
87 σ. : πιν. ; 30 εκ. |
| Language |
Greek |
| Subject |
Ophthalmology |
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Visual Perception |
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Οπτική αντίληψη |
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Οφθαλμολογία |
| Issue date |
2007-07-26 |
| Collection
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School/Department--School of Medicine--Department of Medicine--Post-graduate theses
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Type of Work--Post-graduate theses
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| Notes |
Διατμηματικό μεταπτυχιακό πρόγραμμα σπουδών: "Οπτική και Όραση". |
| Permanent Link |
https://elocus.lib.uoc.gr//dlib/e/2/a/metadata-dlib-c9ae19cbe33a653bc97673afb66c49a2_1260851035.tkl
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| Views |
188 |
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