Abstract
Purpose :
To compare 12X12mm widefield en face swept source optical coherence tomography (SS-OCT) imaging with conventional color, autofluorescence, and infrared imaging for the detection of reticular pseudodrusen (RPD) in eyes with dry age-related macular degeneration (AMD).
Methods :
Patients with dry AMD were prospectively enrolled in an OCT imaging study at the Bascom Palmer Eye Institute. On the same day, all patients underwent color fundus imaging, fundus autofluorescence imaging, infrared reflectance imaging, and imaging with a prototype Zeiss 100kHz SS-OCT instrument (Carl Zeiss Meditec Inc., Dublin, CA) with a central wavelength of 1050nm. Two masked graders assessed the presence, absence, or uncertainty of RPD on the conventional images and separately on four different SS-OCT en face images. The four OCT images were the OCT fundus image (OFI), a sub-RPE slab image, and two 20 µm thick outer retinal slabs positioned 35-55 µm and 20-40 µm above the RPE. The OCT fundus image (OFI) and sub-RPE slab image were used to assess the presence of geographic atrophy, the outer retinal slab images were used to assess the presence of subretinal drusenoid deposits. The grading results between conventional imaging and SS-OCT en face imaging were compared, and questionable RPD cases were defined as absent RPD to simplify analysis. Since RPD could be detected using both imaging modalities, it was decided that the gold standard for the presence of RPD grading would be a positive reading with either SS-OCT or conventional imaging.
Results :
A total of 307 eyes (209 patients) were graded for the presence or absence of RPD based on SS-OCT and conventional imaging. The agreement between SS-OCT and multimodal imaging was 83%. The difference in RPD detection with either image modality was not statistically significant (p=0.21). The sensitivity of SS-OCT in RPD detection was 83%, and when using conventional imaging, the sensitivity was 75%. When using SS-OCT imaging alone, 10% of RPD cases would be missed, and when using conventional imaging alone, 14% or RPD cases would be missed.
Conclusions :
All four imaging modalities used together provided the best strategy for the detection of RPD. However, when using widefield en face SS-OCT slab imaging alone, the detection of RPD was at least as good as conventional imaging.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.