Janssens, M.S.A. (2013) Laterale inhibitie in het gezonde oog van de mens. thesis, Medicine.
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Abstract
Background: Glaucoma is a disease characterized by progressive optic nerve degeneration that results untreated in irreversible blindness. Glaucoma patients have difficulty with light and dark adaptation beginning, which could be explained by decreased lateral inhibition in the retina: the capacity of a retinal ganglion cell to reduce the activity of its neighbors. By the time a perimeter measures a reduced response, there are already many ganglion cells lost. This also could be explained by a decreased lateral inhibition. The purpose of this study was to determine lateral inhibition which means a loss of ganglion cells, with a better measurement set up to use for glaucoma patients in the future. Material: In a pilot study: spatial frequency (1, 2, 4, 8 cycles per degree; cpd) and temporal frequencies (0.75, 1.5, 3.0, 6.0 Hertz; Hz), were recorded from ten young (age range, 18-35 years) healthy subjects to determine lateral inhibition in the eye. These results were found with two different tests: contrast sensitivity test and illusion test. The subjects were tested three times; every visit, four spatial and four temporal frequencies were measured. Results: Nine subjects (90%), of which six women (67%), with an average age of 26 (range 24-33) were included in the contrast sensitivity experiment. In the illusion test seven subjects (70%), of which five women (71%), with an average age of 27 (range 24-33) were included. There is a significant difference between the spatial frequencies 1 and 4 cpd (p<0.001) – note lateral inhibition and the contrast sensitivity function is correct. In the illusion test compensation amplitude is significant difference of zero (p<0,05) – note lateral inhibition. The best temporal frequency is between 1.5 and 3.0 Hz. Conclusion: For measuring lateral inhibition, the set up of the contrast sensitivity experiment is suitable with spatial frequency 1 and 4 cpd. With the illusion test, 2.0 Hz is the best temporal frequency to determine lateral inhibition in the eye.
| Item Type: | Thesis (Thesis) |
|---|---|
| Supervisor name: | Jansonius, Prof. Dr. N.M. |
| Faculty: | Medical Sciences |
| Date Deposited: | 25 Jun 2020 10:43 |
| Last Modified: | 25 Jun 2020 10:43 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/500 |
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