Fundus autofluorescence imaging in an ocular screening program

Abstract

Purpose. To describe integration of fundus autofluorescence (FAF) imaging into an ocular screening program. Methods. Fifty consecutive screening participants were included in this prospective pilot imaging study. Color and FAF (530/640 nm exciter/barrier filters) images were obtained with a 15.1MP Canon nonmydriatic hybrid camera. A clinician evaluated the images on site to determine need for referral. Visual acuity (VA), intraocular pressure (IOP), and ocular pathology detected by color fundus and FAF imaging modalities were recorded. Results. Mean ± SD age was 47.4 ± 17.3 years. Fifty-two percent were female and 58% African American. Twenty-seven percent had a comprehensive ocular examination within the past year. Mean VA was 20/39 in the right eye and 20/40 in the left eye. Mean IOP was 15 mmHg bilaterally. Positive color and/or FAF findings were identified in nine (18%) individuals with diabetic retinopathy or macular edema (n = 4), focal RPE defects (n = 2), age-related macular degeneration (n = 1), central serous retinopathy (n = 1), and ocular trauma (n = 1). Conclusions. FAF was successfully integrated in our ocular screening program and aided in the identification of ocular pathology. Larger studies examining the utility of this technology in screening programs may be warranted.

Figure 1

Flow chart of imaging results and referral patterns. Abbreviations: DME: diabetic macular edema; AMD: age-related macular degeneration; CSR: central serous retinopathy; RPE: retinal pigment epithelium.

Figure 2

(a, b) Compared to color, FAF imaging identified a larger number of dot-blot hemorrhages and microaneurysms and was superior at outlining RPE disturbances. (c, d) Perifoveal RPE hypopigmentation was evident on the color image, while extensive focal RPE defects were seen on FAF imaging. (e, f) FAF versus color imaging showed more detail in terms of the extent of RPE disturbance. (g, h) A faint circular lesion was seen nasal to the fovea on color imaging. FAF imaging was superior to color imaging at characterizing the full extent of this lesion by delineating RPE hyperfluorescence and damage. (i, j) Extensive fibrosis was appreciated on color imaging, while FAF imaging further delineated an extensive area of RPE degeneration. (k, l) Diabetic macular edema with extensive hard exudates were clearly identified on color but not FAF imaging.