Abstract
Purpose: :
Fundus Autofluorescence (FAF) imaging utilizes higher flash intensity settings than conventional imaging. Therefore, we set out to demonstrate the safe integration of FAF imaging in community-based screenings using a non-mydriatic digital retinal camera.
Methods: :
Anterior and posterior segment color imaging and FAF of both eyes were obtained using a Canon CX-1 camera with a 530-580 nm excitation filter, a 640 nm barrier filter, and a flash of 300 watts-seconds (W-sec). The following parameters were assessed pre- and then post-imaging as part of a safety analysis of FAF imaging during community based screenings: 1) Snellen visual acuity (VA); 2) non-dilated pupil size (Retinomax K-plus3, Right-on Medical, Tokyo, Japan); 3) color vision using Ishihara Color Plates; 4) 20-degree central visual field sensitivity using frequency doubling technology (FDT, Carl Zeiss Meditec, CA, USA); and 5) non-contact intraocular pressure (IOP) tonometry (Canon TX-f, Tokyo, Japan).
Results: :
Data from 61 participants (mean age, 42 years; range, 20-77 years) were analyzed (40% White, 28% African American, 20% Asian, 10% Hispanic, and 2% other). There were no deleterious visual effects from FAF flash exposure. Mean pre-imaging VA was 20/24 (right eye) and 20/25 (left eye). Snellen acuity as well as visual field testing by FDT were not affected by the FAF flash. Color vision recovered within 120 sec and pupil size within 60-180 sec of FAF flash exposure. Non-mydriatic imaging was successful in eyes of different pupil size and iris color (brown (71%), blue (14%), hazel (10%), and green (5%)). The mean pre- and post-imaging pupil size was 4.4 mm (range, 2-7.6 mm) and 3.9 mm (range, 2-7.5 mm). All participants had healthy posterior poles except for one with bilateral glaucomatous optic nerve changes and another with macular drusen (left eye only).
Conclusions: :
No adverse effects were noted after FAF imaging. Including FAF imaging in screening programs for early detection of retinal disorders is safe and outweighs the temporary discomfort of the higher flash intensity. The use of the CX-1 in FAF mode is not harmful to patients and leaves no sequelae after a period of 180 Sec.
Keywords: imaging/image analysis: non-clinical • ipofuscin • retina