Recently, a novel optical imaging technique was successfully used in measuring the functional
response of living retinal tissues. The technique, functional ultra high resolution
optical coherence tomography, measures localized differential changes in the retina reflectivity
over time resulting from external white light stimulation. This result can be used to
develop a non-invasive diagnostic method for the early detection of retinal diseases. However,
the physiological causes of the experimentally observed optical signals, most of which
originate from the photoreceptors layer, are still not well understood. Due to the complexity
of the photoreceptors, using purely experimental methods to isolate the changes in
light reflectivity corresponding to individual physiological processes is not feasible. Therefore,
we have employed the finite-difference time-domain method to model the changes in
light scattering patterns of the photoreceptor cells caused by light-induced physiological
processes. Processes such as cell swelling, cell elongation and hyperpolarization of doublelipid
membrane structures were simulated by changing the size parameters and optical
properties of the cells components. Simulation results show that the hyperpolarization of
double-lipid membranous structures and cell swelling are the most likely causes for the
experimentally observed changes in optical reflectivity. A number of experiments were
suggested to verify the conclusions drawn from this numerical work. This numerical work
includes an analysis of various errors in FDTD computational models.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OWTU.10012/3373 |
| Date | January 2007 |
| Creators | Abdallah, Samer S. |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
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