Abstract
Purpose: :
Alterations of the retina bloodstream are the cause of the most ocular diseases. The blood flow and blood oxygenation represent the most important parameter to characterize the retina metabolism. To derive the oxy-haemoglobin blood content in optic nerve capillary, Diaconu (2009) proposed a linear mathematical model that fully explains the reflectometry functions. The aim of the present study was to apply this linear model to derive oxy-haemoglobin blood content from the reflectometry functions on retinal veins and arteries.
Methods: :
The reflectometry function from 450 nm to 680 nm on the arteries and veins from the optic nerve zone of 6 healthy subjects was measured by the multi-channel technique (800 wavelengths).
Results: :
The modeling results demonstrate that the walls of the arteries and veins contain unknown elements that have a supplementary contribution to the spectral absorption function of haemoglobin and derivatives. To resolve this unknown parameter we added to the model a multi-Gaussian function capable to retrieve the spectral absorption function of different unidentified biochemical components which could contribute to the overall absorption function.
Conclusions: :
i) The spectral reflectometry function on the arteries and veins includes information from the blood contained in the wall of these structures and not from the blood contained in the vessel volume. ii) The spectral reflectometry function on the walls of the arteries and veins may contain information on the various components of cytochrome oxidase.
Keywords: imaging/image analysis: clinical • oxygen • blood supply