- Shoot ALL DARC study patient Indocyanine Green (ICG) Angiograms with the camera set at 50 degrees angle of view, for two reasons:
- The protocol for the Digital Angiography Reading Center (DARC) requires this angle of view.
- The Zeiss FF450+IR with Visupac has a flash boost mode (see 9 below) that increases flash power only at the 50 degree angle of view setting.
- Red-free (green) photos using normal exposure
- Focusing for ICG:
- Obtain sharp image of macula using red-free (green) filter.
- Look at the setting of the eyepiece of the FF450+IR camera.
- Adjust the setting on the camera ocular -4.5 diopters from your normal setting, that is, turn the eyepiece 4.5 lines to the minus direction from the setting you used for focusing on the macula.
- Focus again on the macula with the new setting using red-free (green) filter; the actual plane of focus is now into the choroid. Any minor focus adjustments, if necessary, should be made by observing the monitor.
- Engage ICG filter system.
- ICG starting flash = 26. This higher flash setting helps to capture early the choroidal filling phase.
- Reduce flash in early arterial-venous phase / mid-phase to a lower setting in order to prevent blowing out the image (blooming).
- For late-phase photography (later than 5 minutes) adjust flash back up to 25 or higher, as required for well exposed image.
- For additional flash intensity during ICG late phase, click the "Boost" button beneath the timer on the left side of the capture screen.
- Remember to return the eyepiece setting to normal setting when finished.
The exposure information listed here is intended as a starting point only.