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

Abstract

Citation: Yoza R, Murakami T, Uji A, et al. Characterization of inner retinal spots with inverted reflectivity on en face optical coherence tomography in diabetic retinopathy. Invest Ophthalmol Vis Sci. 2016;57:186257: -187057: . DOI:10.1167 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 6 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.

Optical coherence tomographic predictor of retinal non-perfused areas in eyes with macular oedema associated with retinal vein occlusion

“…Second, we evaluated only the cross-sectional OCT images that passed vertically through the fovea. Recently, Yoza et al reported that the spots with inverted reflectivity in the RNFL and ganglion cell layer in the en face SS-OCT images in a 6×6 mm areas were associated with the disruption of the neurovascular units in diabetic retinopathy 29. Therefore, prospective studies with contiguous OCT scans of the macular region may be able to evaluate the relationship between the OCT findings and the presence of retinal non-perfused areas more accurately.…”

Diabetic Neuroglial Changes in the Superficial and Deep Nonperfused Areas on Optical Coherence Tomography Angiography

“…26 Another OCT finding in the inner retinal layers, the spot with inverted reflectivity on OCT images using the Optovue RTVue XR Avanti, also was evaluated according to modified methods as described previously. 27 We sometimes found welldefined spots with lower reflectivity in the NFL and higher reflectivity in the GCL/IPL in the sNPA, after the en face OCT images in the NFL or GCL were constructed using the manual setting of the inner and outer borders of these layers in the localized areas. When the boundary between the GCL and IPL was indefinite, we constructed en face images from the inner border of the GCL to the center of the GCL/IPL to evaluate the patchy lesions in the GCL.…”

“…Intriguingly, the sNPA had inner retinal lesions, that is, inner retinal spots with inverted OCT reflectivity and no boundary between the NFL and GCL/IPL. 26,27 The dNPA was accompanied frequently not only by neuroglial changes in the corresponding layer, that is, cystoid spaces, but also by morphologic changes in other layers. These data suggested the clinical feasibility of a three-dimensional evaluation of the disruption in the neurovascular units in DR.…”

“…We evaluated the structural changes in the neuroglial tissues corresponding to the NPA in individual layers, that is, areas with no boundary between the NFL and GCL/IPL, inner retinal spots with inverted OCT reflectivity, and cystoid spaces in the INL and HFL. 20,26,27 The transverse lengths of these lesions were individually quantified using the ImageJ software as described above. The OCT reflectivity of the NFL is much higher than that of the GCL/IPL on B-scan images in healthy eyes, which enabled identification of the boundary between these layers.…”

“…26 En face OCT images delineate inner retinal spots with lower OCT reflectivity in the NFL and higher reflectivity in the GCL, referred to as inner retinal spots with inverted OCT reflectivity, most of which are seen in the hypofluorescent areas. 27 However, it is largely unknown how the lamellar capillary nonperfusion contributes to the development or progression of these neuroglial lesions and concomitant visual impairment in DR.…”