Abstract
Purpose :
To demonstrate the usability of fundus autofluorescence (FAF) images acquired using a prototype widefield (WF) slit-scanning ophthalmoscope (SSO) (ZEISS, Dublin, CA), imaging over a 90° field of view (FOV) as measured from the cornea.
Methods :
A prototype WF SSO was used to acquire 90° FAF images on 8 undilated eyes from 6 subjects with and without ocular disease, as well as True Color images for comparison. FAF is dye-less fluorescence imaging using either blue (FAF-Blue) or green (FAF-Green) illumination, which captures the natural autofluorescence of lipofuscin that accumulates in the retinal pigment epithelium (RPE). Image quality was evaluated by a licensed optometrist. Images were graded as unusable if image artifacts disrupted the ability to evaluate the central 45 degree field of view.
Results :
Of the 16 non-mydriatic FAF images acquired, 81% (13/16) were usable. The 19% (3/16) of unusable FAF images occurred because the subjects’ pupil diameters were smaller than 2.5mm, the system’s limit. FAF-Blue, FAF-Green, and True Color images, each spanning a 90° FOV, are presented for a subject with a history of trauma in the left eye secondary to a car accident and status post multiple ocular surgeries (Figure 1). Both FAF images show an area of hypofluorescence superior to the optic disc, corresponding to a region of dead RPE cells. This area is not seen on the True Color image as True Color imaging does not provide functional information on the status of RPE cells. An area of peripapillary atrophy encircling the optic disc can be seen in the True Color image, and a corresponding region of hypofluorescence is present in both FAF images. Finally, accumulation of lipofuscin can be seen in the region inferior nasal to the macula as an area of hyperfluorescence in both FAF-Blue and FAF-Green images.
Conclusions :
The prototype widefield slit-scanning ophthalmoscope is capable of acquiring 90° FAF-Blue and FAF-Green images on undilated eyes. These images provide functional information regarding the presence of dead RPE cells, missing RPE cells, and the accumulation of lipofuscin.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.