Zeiss CIRRUS HD-OCT 500, User Manual

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Posterior Segment
2660021169012 Rev. A 2017-12 CIRRUS HD-OCT User Manual
8-22
NOTE: Signal strength and image quality can be significantly reduced when the imaging
aperture (the lens) is dirty or smudged. If you suspect this problem, follow the instructions
to clean the "
Imaging Aperture Lens and External Lenses" on page 12-3 .
Ganglion Cell OU Analysis
Ganglion Cell OU Analysis 1 measures the thicknesses for the sum of the ganglion cell layer
and inner plexiform layer (GCL + IPL layers) in both eyes. Comparisons can then be made
with normative data (
Appendix-A ).
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The thickness maps (upper left and right of Figure 8-15 ) indicates thickness
measurements of the GCL + IPL in the 6 mm by 6 mm cube and contains an elliptical
annulus centered about the fovea.
A Deviation Map shows a comparison of GCL + IPL thickness to normative data (red to
indicate thinner than all but 1% of normals, yellow to indicate thinner than all but 5% of
normals) while a thickness table shows average and minimum thickness within the
elliptical annulus.
Sectors in the lower portion of the screen divide the elliptical annulus of the Thickness Map
into 6 regions: 3 equally sized sectors in the superior region and 3 equally sized sectors in
the inferior region.
The slice navigator in the Vertical B-scan is used to adjust to a different Horizontal B-scan.
The purple segmentation line represents the inner boundary of the ganglion cell layer,
which is also the outer boundary of the retinal nerve fiber layer. The yellow line represents
the outer boundary of the inner plexiform layer. The maps shown and quantitative values
reported represent the combined thickness of the ganglion cell layer plus inner plexiform
layers.
1 Ganglion Cell OU Analysis is an optional feature that may not be available in all markets, and when available in a market, may not
be activated on all instruments. If you do not have this feature and want to purchase it, contact ZEISS. In the U.S.A., call
1-877-486-7473; outside the U.S.A., contact your local ZEISS distributor.