Retinopathy Effects on Distribution of Individual Macrophage-Like Cells Imaged on the Vitreoretinal Interface Using Clinical OCT

Abstract

Purpose : Clinical imaging of retinal macrophage-like cells on the vitreoretinal interface could be an important biomarker of inflammation response in retinal diseases. Here we analyzed distribution and morphology of these cells in a variety of retinal pathologies imaged using a clinical OCT.

Methods : 17 controls, 17 glaucoma patients, 13 patients with various stages of diabetic retinopathy, 9 SCR patients, and 5 RVO patients, were imaged using a clinical SD-OCT system (Avanti RTVue-XR; Optovue). Ten 3x3mm scans centered at 9 ° temporal to the fovea were obtained and averaged.^a A 3µm OCT-Reflectance (OCT-R) slab located above the ILM surface was used for macrophage-like cell density and nearest neighbor distance (NND) measurements. Measurements were performed on a 500x500 µm ROI near the center of the OCT-R. In patients, macrophage-like cells arranged in clusters. A 500x500 µm ROI was used to measure macrophage-like cells within these structures. Axial length was obtained for magnification correction.

^aPMID:28068370

Results : Ramified macrophage-like cells in control eyes were distributed uniformly over the surface of the ILM. In pathological eyes, cells were ramified but less slender unevenly clustered around targets of activity. In controls, mean±SD cell density was 81±26 cells/mm² (range: 44-156 cells/mm²) and NND was 71.5±15.6 µm (range: 52.0-108.8 µm), In glaucoma mean±SD cell density was 26.93±20.4 cells/mm² (range: 6.46 – 47.33) and NND was 156.89±63.84 µm (range: 93.05 – 220.73). In diabetic eyes, mean±SD cell density was 157±53 cells/mm² (range: 104-224 cells/mm²) and NND was 53.2±10.8 µm (range: 45.2-69 µm). In SCR mean±SD cell density wwas 56±21.66 cells/mm² (34.34 – 77.66) and NND was 109.40±47.53 µm (61.87 – 156.93). In RVO mean±SD cell density was 84.8±59.62 cells/mm² (range: 28.18 – 144.42) and NND 160.15±177.64 µm (0 – 337.79).

Conclusions : Distributions of macrophage-like cells were non-uniform in different retinopathies, suggesting migration towards sites of retinal damage. While their exact origin is unknown the ability to study their behavior in vivo using clinical instrumentation offers opportunities for investigating their role in retinal injury and response to therapy.

This is a 2020 Imaging in the Eye Conference abstract.

 

In vivo imaging of macrophage-like cells using clinical OCT. Top row: 3μm OCT-R slab located above the ILM surface. Bottom row: Overlay of OCT-R(green) and respective OCT-A (red) images.