Widefield En Face Optical Coherence Tomography Imaging of Subretinal Drusenoid Deposits

BACKGROUND AND OBJECTIVE: To determine whether subretinal drusenoid deposits (SDD) can be detected on widefield en face slab images derived from spectral-domain (SD) and swept-source (SS) optical coherence tomography (OCT) volume scans. PATIENTS AND METHODS: Retrospective study of patients with dry age-related macular degeneration (AMD) enrolled prospectively in an OCT imaging study using SD-OCT (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, CA) with a central wavelength of 840 nm, and a prototype 100-kHz SSOCT instrument (Carl Zeiss Meditec) with a central wavelength of 1,050 nm. Seven en face slabs were evaluated with thicknesses from 20 to 55 mu m and positioned at distances up to 55 mu m above the retinal pigment epithelium (RPE). A montage of 6 x 6 mm SD-OCT en face images of the posterior pole from each patient was compared with a 9 x 12 mm SS-OCT single en face slab image and with color, autofluorescence, and infrared reflectance images. RESULTS: A total of 160 patients (256 eyes) underwent scanning with both OCT instruments; 57 patients (95 eyes) also underwent multimodal fundus imaging. Of 95 eyes, 32 (34%) were diagnosed with reticular pseudodrusen (RPD) using multimodal imaging. All eyes with RPD demonstrated a pattern of SDD on widefield en face OCT similar to that observed for RPD. The en face slab image that consistently identified SDD was the 20-mu m thick slab with boundaries from 35 to 55 mu m above the RPE. CONCLUSION: Widefield en face slab imaging with SD-OCT and SS-OCT can detect SDD and could replace multimodal imaging for the diagnosis of RPD in the future.