Characterization of Inner Retinal Spots With Inverted Reflectivity on En Face Optical Coherence Tomography in Diabetic Retinopathy

PURPOSE. The purpose of this study was to characterize inner retinal spots with inverted reflectivity on en face images of swept-source optical coherence tomography (SS-OCT) in diabetic retinopathy (DR). METHODS. We retrospectively reviewed seventy-five eyes of 75 patients with DR (15 eyes with individual grades of DR severity). We obtained three-dimensional images (6 3 6 mm) centered on the fovea, followed by the generation of en face images. We investigated the morphologic characteristics of spots with inverted reflectivity, which had lower reflectivity than the surrounding areas in the nerve fiber layer (NFL) and higher reflectivity in the ganglion cell layer (GCL). RESULTS. Thirty-seven of 45 eyes (82.2%) with moderate nonproliferative diabetic retinopathy (NPDR) or more severe grades were accompanied with well-defined spots with inverted reflectivity, whereas 30 eyes with no apparent retinopathy or mild NPDR had no such lesions. These spots had various shapes in the NFL and GCL on en face OCT images; the mean area was 0.126 +/- 0.052 mm(2) at the NFL level. In all 75 eyes, 153 of 184 spots (83.2%) were localized in the NFL and GCL, whereas 31 spots (16.8%) extended to retinal layers deeper than the GCL. One-hundred sixty-nine spots (91.8%) were not visible on color fundus photographs, and 15 spots (8.2%) were accompanied by whitish-yellow lesions in the corresponding areas. In 45 eyes for which fluorescein angiography images were obtained, mild hypofluorescence was seen in 156 spots (84.8%) and focal nonperfused areas in 17 spots (9.2%). CONCLUSIONS. En face images of SS-OCT showed spots with inverted reflectivity in the NFL and GCL in DR.