Purchase this article with an account.
B. Khoobehi, H. Wafapoor, A. M. Eaton, M. Moghareh, R. Grigorian, S. Miles, E. Puissegur, E. Tinsley; Using Hyperspectral Imaging to Investigate Oxygen Saturation in ONH Tissue in Primate’s Eyes during the Development of Experimental Early Phase Glaucoma. Invest. Ophthalmol. Vis. Sci. 2009;50(13):5804.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate oxygen saturation in ONH tissues and in retinal artery/vein pairs in experimentally induced early- phase glaucoma using a primate animal model.
Hyperspectral imaging (HSI) that interfaces with a fundus camera was used to detect the spectral signature of oxy- and deoxyhemoglobin from reflected light. Captured images were broken down to 100 different images from 500-700 nm with 2 nm resolution. Five normal cynomolgus monkeys 4 to 4.5 years of age and 2.5 to 3 kg body weight were used. For an HSI session (oxygen saturation measurement), each monkey was anesthetized. HIS imaging was performed every other week for a period of 10 months. One eye of each monkey was lasered (trabecular meshwork). The laser power was 300-1500 mW, duration 100 ms and the spot size was 50 µm. The laser procedure was repeated until the intraocular pressure (IOP) maintained a stable and moderate elevation. Compliance testing involving the use of confocal scanning laser tomography to measure the parameter mean position of the disc (MPD), which describes the position of the surface of the ONH relative to the peripapillary retinal nerve fiber layer. Both eyes of each monkey were compliance tested on three separate occasions to provide the pre-laser MPD ± 95% confidence interval for normal eyes.
The IOP of a normal eye is 7.8 mm Hg and the IOP of a lasered eye is 12.82 mm Hg. On the average, 8 weeks were required to achieve early glaucoma (EG) from onset of IOP elevation. The results of oxygen saturation calculated from oxy/deoxy spectrum are summarized in the Table.
The differences between the various tissues including the vein were significantly different before and after the onset of glaucoma, except for the artery. This technique detected changes in oxygen saturation as low as 4%
This PDF is available to Subscribers Only