General Acquire Procedure2660021169012 Rev. A 2017-12 CIRRUS HD-OCT User Manual6-28• Enhance Live Scan allows you to adjust the polarization (X,Y–offsets) ofposterior segment live scans. Associated up and down arrow buttons enable you toadjust each manually.NOTE: HD Angle scans are not aligned to the corneal vertex.NOTE: If a button or menu option does not appear on the Acquisition screen for yourcurrent scan selection then that function is not available for the current scan.General Acquire ProcedureThis section contains information about acquiring scans supported in CIRRUS HD-OCT.NOTE: Review both the "Acquire Screen and Controls" on page 6-19 and "Set Upfor Maximum Image Quality" on page 6-31 sections prior to acquiring scans.Once you have selected the patient of interest, the Acquire button at the bottom of thePatient screen becomes selectable.NOTE: The first scan selection and scan of the day will run slightly slower than all laterscans.NOTE: To minimize errors and artifacts, acquire OCTA Cube scans with FastTrac on.• HD Line 100x: A single high definition OCT B-scan, using 1024 A-scans, withselectable B-scan averaging 100 frames with an adjustable length from 3 mm to9 mm and an adjustable angle from 0 to 90 degrees.To Begin Scan Acquisition:1. Ensure that the Patient is fully prepared for the scan as described in "Patient GoodPractices" on page 5-1.2. Select Acquire. The screen will change to indicate the scan types available.3. Select the scan type of interest4. Ask the patient to hold their gaze and head steady (as the chinrest will be moving)and select Auto Focus in the Fundus Viewport.5. Left–click the pupil center of the live image in the Iris Viewport to center the scanbeam through the pupil.6. After Auto Focus, check the Iris Viewport to ensure that the pupil is still centered. Ifthe Fundus Viewport turns dark following Auto Focus, center the pupil, click ,then click the Auto B/C button. If additional brightness and contrast changes arenecessary, use the appropriate slider controls.7. Further adjust the chinrest manually, if necessary, by use the circular X-Y control (see"Iris Viewport (Posterior Segment Scan) and Anterior Segment ScanPatterns" on page 6-29). Use Z controls (left–right arrows or mouse scroll wheel)to reach the proper working distance by bringing the iris image into focus.8. Use Enhance (polarization) and Center (Z-offset) (posterior segment scans only)buttons and sliders to the left help you improve the scan image quality and center itvertically.
