Scan Acquisition Protocols
Stratus OCT User Manual PN 2660021134133 A
4-6
image appears most nearly horizontal on your monitor. Try to minimize this variation by
adjusting the patient module laterally by small amounts. This adjusts where the scan beam
enters the pupil and its angle of incidence on the retina.
Scan Protocol Descriptions, Options And Tips
There are two basic scan patterns: lines and circles. The Stratus OCT constructs all scan
protocols from line or circle scans. Below are descriptions of each scan protocol along with
its adjustment options and tips. For instructions to adjust scan size, angle or number of
lines, see
Adjust Scan Pattern Parameters on page 3-14. To Adjust Scan
Placement, see page 3-8. To Optimize Scan Image, see page 3-6.
Time-Efficient or Fast Scans
The four time-efficient or fast scan protocols are designed to simplify the process and
shorten the time to acquire the scan series used most frequently to detect glaucoma or
other retinal pathologies. All four protocols share the following characteristics and
advantages:
• They combine a three-scan or six-scan series into one scan acquired in 1.92 seconds.
• All parameters are fixed: you cannot adjust scan size or the number of lines.
• Scan alignment and placement are required only once.
• They may improve the accuracy of relative scan placement among the lines or circles
compared to acquiring scans one by one, because scans are acquired at almost the
same time.
• You can acquire multiple scans without returning to the MAIN WINDOW. In effect, this
enables you to repeat whole scan series for later analysis and comparison.
• After saving a fast scan, you can switch between the left and right eyes without
returning to the M
AIN WINDOW. The Stratus OCT automatically detects which eye is
being scanned and adjusts the display accordingly.
• They each acquire 768 A-scans total. These 768 A-scans are less than the total
A-scans acquired one by one at 512 A-scans per line or circle. Note, however, that it is
more than adequate for meaningful analysis with the applicable analysis protocols.
Increased resolution for the fast scan types would require three or more seconds of
scanning, which tends to introduce greater errors from patient movement.
Specialized Display of Fast Scans
The real-time scan image automatically divides into either a 3x2 display—for Fast Macular
Thickness Map, Fast Optic Disc and Fast RNFL Map—or a 3x1 display—for Fast RNFL
Thickness (3.4)—so that you can observe each line or circle scan separately as it updates,
and align appropriately.
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