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Title: Retinal perfusion imaging of the human eye using a scanning laser ophthalmoscope
Author: Rasta, Seyed Hossein
ISNI:       0000 0001 3508 7773
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 2007
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This study investigated the feasibility of assessing fundus oxygen perfusion in the human eye by adapting a spectral confocal scanning laser ophthalmoscope (cSLO). The Aberdeen prototype cSLO was adapted to use two wavelengths simultaneously performing a spectral analysis of the status of the retina tissue to give the ability of imaging the perfusion in the human eye. In order to image retinal perfusion a new combination of two wavelengths (red and infrared) was chosen to produce a linear relationship between oxygen saturation and optical density ratio of blood according to the Beer & Lambert law. The technique was evaluated using measurements made on a model eye, fourteen volunteers' normal eyes and seven eyes containing diabetic retinopathy. The reproducibility of the measurements of reflected light for the eye using the Aberdeen SLO was investigated. A model eye was designed and varieties of different elements of the SLO using the model were studied. It also was necessary to process SLO images to give uniform data improving the reproducibility of the measurements. So, an algorithm for image correction was developed to minimize the intensity variation across the image. The relative oxygen levels of retinal blood vessels (artery and vein) were successfully determined using this method. Retinal perfusion imaging (RPI) is a new technique that showed promise in the diagnosis of the non-perfused parts of the retina as well as normal regions using a pseudo-colour map. It has been shown RPI using the cSLO has advantage over fluorescein angiogram in that it can image relative oxygen saturation levels of the retina.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available