Thirty-seven normal and primary open angle glaucoma (POAG) subjects were noninvasively imaged by a tailor-made real-time anterior segment swept source optical coherence tomography (SS-OCT) to demonstrate the differences of the Schlemm's canal (SC) between POAG and normal eyes. After the cross-section images of the anterior chamber angle were acquired by SS-OCT, SC was confirmed by two independent masked observers and the average area, long diameter, and perimeter of the SC were measured. In normal subjects the circumference, area, and long diameter is 580.34±87.81 μm, 8023.89±1486.10 μm2, and 272.83±49.39 μm, respectively, and these parameters were 393.25±98.04 μm, 3941.50±1210.69 μm2, and 190.91±46.47 μm in the POAG subjects. The area of SC in the normal ones was significantly larger than that in POAG eyes (p<0.001), so as the long diameter and the perimeter (p<0.001; p<0.001).
We introduce an automatic technique to stitch retinal images recorded with an adaptive optics confocal scanning laser ophthalmoscope (AOSLO). The AOSLO images whose field size is 1.5 deg are recorded while the fixation target is moving according to a square pattern so as to cover a wide field of view. Principal components analysis-scale invariant feature transform is used to extract and match point features of the retinal images. With the matched point features, the affine transformation is used to stitch the images to generate eight montaged images. Then, the eight images are stitched together to construct a wide-field image by a cross-correlation algorithm. An image blending algorithm is also developed to reduce seam artifacts. With the proposed algorithms, a montage whose field size is approximately 10.5×9.6 deg is constructed.
We have used anterior segment swept source optical coherence tomography to measure Schlemm’s canal (SC) morphometric values in the living human eye. Fifty healthy volunteers with 100 normal eyes were measured in the nasal and temporal side. Comparison with the published SC morphometric values of histologic sections proves the reliability of our results. The statistical results show that there are no significant differences between nasal and temporal SC with respect to their diameter, perimeter, and area in our study (diameter: t=0.122, p=0.903; perimeter: t=−0.003, p=0.998; area: t=−1.169, p=0.244); further, no significant differences in SC morphometric values are found between oculus sinister and oculus dexter (diameter: t=0.943, p=0.35; perimeter: t=1.346, p=0.18; area: t=1.501, p=0.135).
We have used an adaptive optics confocal scanning laser ophthalmoscope to assess oxygen saturation in small retinal vessels. Images of the vessels with a diameter smaller than 50 μm are recorded at oxygen sensitive and isosbestic wavelengths (680 and 796 nm, respectively). The vessel optical densities (ODs) are determined by a computer algorithm. Then, OD ratios (ODRs), which are inversely proportional to oxygen saturation, are calculated. The results show that arterial ODRs are significantly smaller than venous ODRs, indicating that oxygen saturation in the artery is higher than that in the vein. To the best of our knowledge, this is the first noninvasive measurement of oxygen saturation in small retinal vessels.
An adaptive optics confocal scanning laser ophthalmoscope (AOSLO) for retina imaging is
devoloped in this paper. By using a wavefront sensor (Shack-Hartmann wavefront sensor with 11×11
lenslet array) to measure aberrations of human eye and a wavefront compensator (37-channel PZT
deformable mirror) to correct for the aberrations, the AOSLO system can acquire near
diffraction-limited image of human retina over the whole field of view (1×1 degree ~ 3×3 degree). The
imaging frequency is 30Hz, which provides a real-time observation of human cone mosaic in vivo. The
system has potential application in early disease diagnose and vision research.
The optical design of a confocal scanning laser ophthalmoscope based on adaptive optics (AOSLO) is described in
this paper. Spherical mirrors are used for pupil relay and astigmatism compensation. The main optical system
achieves diffraction-limited performance through the entire scanning angle (6mm pupil, 3 degree on pupil plane).
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.