Proliferative diabetic retinopathy and diabetic macular edema are two factors that increase macrophage-like cell density characterized by en face optical coherence tomography

Abstract

Background Macrophage-like cells (MLCs) located at the ILM were observed in live human retinas using adaptive optics optical coherence tomography (OCT) as well as clinically-used OCT. The study aimed to quantitatively analyzing MLCs at the vitreoretinal interface (VRI) in diabetic retinopathy (DR) using en face OCT and swept-source optical coherence tomography angiography (SS-OCTA). Methods 190 DR eyes were included in the study, with 70 proliferative diabetic retinopathy (PDR) eyes and 120 non- proliferative diabetic retinopathy (NPDR) eyes. Sixty-three eyes from normal subjects were included as controls. MLCs were visualized in a 5 μm en face OCT slab above the VRI centered on the fovea. Mann-Whitney U test and Kruskal-Wallis H test were used to compare the OCTA parameters and the MLC parameters among groups. We evaluated the MLC density among groups on binarized images after image processing. We also investigated the relationship between MLC density and other OCT parameters including retina thickness and vessel density (VD). Results The MLC density significantly increased in PDR eyes (PDR vs. NPDR, 8.97 (8.40) cells/mm2 vs.6.14 (8.78) cells/mm2, P = 0.013; PDR vs. normal, 8.97 (8.40) cells/mm2vs. 6.48 (6.71) cells/mm2, P = 0.027) and diabetic macular edema (DME) eyes (DME vs. without DME, 8.94 (8.26) vs.6.09 (9.00), P = 0.005). After adjusting for age and gender, MLC density in NPDR eyes negatively correlated to VD of deep capillary plexus (DCP) (P = 0.01). Conclusions SS-OCTA is a non-invasive and simple method for the characterization of MLCs at the VRI. PDR and DME are two factors that increase MLC density. MLC density also correlated with VD.

Quantifying Putative Retinal Gliosis in Preclinical Alzheimer's Disease

“…A single retinal biomarker may not be sensitive or specific to AD because the biomarker may be indicated in other retinal diseases. For example, putative retinal gliosis has been indicated in glaucoma, 45 , 48 – 50 diabetic retinopathy, 51 – 53 retinal vein occlusion, 54 and ERM. 63 Even though these conditions were clinically excluded from our study, it may explain the reason why the multimodal model of putative retinal gliosis and RNFL thickness yielded a better AUC and specificity compared to the unimodal of putative retinal gliosis alone.…”

“…SD-OCT en face images of individual retinal layers can be generated from dense or volume scans by using information segmented from specific retinal layers. 44 – 47 Putative retinal gliosis (activated retinal astrocytes, microglia, and Müller cells) has been quantitatively characterized as hyper-reflective patches on SD-OCT en face images that correspond to similar structures on the b-scans in glaucoma, 45 , 48 – 50 diabetic retinopathy, 51 – 53 and retinal vein occlusion. 54 The presence of these hyper-reflective structures (putative gliotic changes) and the extent of retinal region covered with them have been reported to have a greater potential of being an indicator for glaucomatous degeneration.…”

“… 45 These areas of putative gliosis are also increased in proliferative diabetic retinopathy compared to nonproliferative and control participants, with patients with diabetic macular edema having larger areas compared to patients with no macular edema. 53 …”

Vitreoretinal Interface Cells Correlate In Vivo With Uveitis Activity and Decrease With Anti-Inflammatory Treatment

“…19 Over the last 2 years, there has been a growing interest in utilizing OCTA and SS-OCT for the visualization of retinal microglia, which appear as hyperreflective bodies that the existing literature identifies as macrophage-like cells. [20][21][22][23][24] However, the term "macrophage" implies cells of myeloid origin. Many tissues, including retina and brain, have immune cells of both yolk sac and myeloid origin.…”