Chen Fred Kuanfu, Khoo Ying Jo, Tang Ivy
From the *UWA Centre for Ophthalmology and Visual Science; †Lions Eye Institute; and ‡Royal Perth Hospital, Perth, Western Australia.
Asia Pac J Ophthalmol (Phila). 2015 Nov-Dec;4(6):334-8. doi: 10.1097/APO.0000000000000142.
The Spectralis Heidelberg retina angiography + optical coherence tomography (OCT) device often fails to acquire near-infrared autofluorescence (NI-AF) due to poor signal because of interference by the beam splitter used for aligning the laser source with the OCT diode light source. We report the rates of successful NI-AF image acquisition using indocyanine green angiography (ICGA) mode (without dye) compared with combined fluorescein angiography (FA) + ICGA mode (without dye) in patients with geographic atrophy (GA).
This was a retrospective review.
Two hundred images from 50 eyes of 25 patients with GA were included. All patients underwent NI-AF imaging using ICGA (787 nm) and combined FA + ICGA (488 + 787 nm) modes in both eyes. Each eye had macula- and disc-centered imaging. The rates of successful image acquisition were compared using McNemar test.
Successful NI-AF acquisition using ICGA was 48% to 52% in macula-centered views and 36% to 56% in disc-centered views. Only 36% of patients had successful bilateral NI-AF imaging. This improved to 100% in all views in both eyes after switching to combined FA + ICGA mode (P < 0.001). Logistic regression showed no patient or ocular factors were predictive of NI-AF acquisition failure in ICGA mode.
Acquisition of NI-AF images in GA using ICGA mode has a high failure rate, which can be eliminated by using combined FA + ICGA mode. This finding has implications on the design of imaging protocols for routine assessment and clinical trials of geographic atrophy.
