Stratus OCT User Manual PN 2660021134133 A
Analysis Protocols
6-25
Available Adjustments for Individual Radial Scan Analysis
• Move the Disc Reference Points: Click and drag the disc reference points to adjust the
analysis. This is the most important interactive functionality because it determines all
the measurements. Carl Zeiss Meditec designed this feature in case the user believes,
based on visual analysis of the scan image, that the disc reference points can be
placed more accurately.
• ReAnalyze button: Click ReAnalyze and the disc reference points will return to their
original positions, along with the resulting measurements.
• Clear Graphics button: Click Clear Graphics to remove the graphic overlay. Click Show
Graphics to reinstate them.
• Zoom: Move the slider up or down to the zoom in or out.
• Surface Sensitivity: Surface sensitivity determines what reflectivity threshold value is
considered to be the anterior surface. Higher sensitivity creates a higher threshold,
meaning potential artifacts and noise are better ignored in defining the surface. This
can affect measurements.
• Cup Offset: This adjustment defines where the cup begins. Increase or decrease the
value by using the left and right arrows.
• Cup Offset for Topo: Adjusts the surface of the cup in the composite image. Increase
or decrease the value by using the left and right arrows.
Optic Nerve Head (ONH) Analysis Results
The right side of the output display features a composite image of the nerve head
constructed from all scans. It does not change as you scroll the individual scans, but it does
incorporate the changes you make to each individual scan analysis. Below the composite
image appears a set of whole optic nerve head measurements of the disc, cup, rim and
disc/cup ratios.
Composite Image Features and Functionality
The composite image traces the outlines of the disc in red and the cup in green. It shows
the longest vertical and horizontal lines across the disc and cup in red and green,
respectively. The nasal (N), inferior (I), temporal (T) and superior (S) quadrants are indicated
along with the eye (OD or OS). For each scan, it shows the disc reference points with a red
cross inside a circle and the cup edges with small green crosses.
• The path of each scan is traced with a blue line, except for the scan currently
displayed on the left side. It is traced in yellow and has a small yellow cross at one
end that indicates its point of origin. You can click each line to change it to the
currently displayed scan. If you adjust the scan image appearance or the placement of
its disc reference points, its scan line will thereafter be traced in a lighter shade of
blue, until you ReAnalyze it. The new position of the disc reference points will be
reflected in the composite image.
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