Macrophage-like cells are still detectable on the retinal surface after posterior vitreous detachment
Jacob M Wang1, Janice X Ong1, Peter L Nesper1
1Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Abstract:
The identity of vitreoretinal interface macrophage-like cells (MLCs) remains unknown and potential candidates include retinal microglia, perivascular macrophages, monocyte-derived macrophages, and/or vitreal hyalocytes. Since hyalocytes are detectable on the posterior vitreous surface after vitreous extraction in animals, we imaged patients with and without posterior vitreous detachment (PVD) to determine if hyalocytes are the principal MLC component. We performed repeated foveal-centered 3 × 3 mm OCT-A images from 21 eyes (11 no PVD and 10 PVD eyes). Images were registered, segmented, and averaged. The OCT slab from 0 to 3 microns above the internal limiting membrane was used to detect MLCs. We calculated MLC density and distribution in relation to the superficial vascular plexus for 3 vascular regions-on vessels, perivascular, and non-vascular. MLC density was 1.8-fold greater in the PVD group compared to the no PVD group (P = 0.04). MLCs in eyes with PVD were increased 1.9-fold on-vessel (P = 0.07), 1.9-fold in the perivascular region (P = 0.12), and 2.2-fold in non-vascular areas (P = 0.22). MLC density was not severely reduced after PVD, suggesting that the majority of MLCs are not vitreal hyalocytes. PVD status is an important parameter in future MLC studies.
Insights
Macrophage-like cells (MLCs) at the vitreoretinal interface are not primarily vitreal hyalocytes, as their density remains high even after posterior vitreous detachment (PVD). PVD status is crucial for future MLC research.
Area of Science:
- Ophthalmology
- Retinal Biology
- Cellular Imaging
Background:
- The cellular origins of macrophage-like cells (MLCs) at the vitreoretinal interface, including retinal microglia, perivascular macrophages, monocyte-derived macrophages, and vitreal hyalocytes, are not fully understood.
- Vitreal hyalocytes are known to be present on the posterior vitreous surface after vitreous extraction in animal models.
Purpose of the Study:
- To investigate whether vitreal hyalocytes constitute the primary component of MLCs at the vitreoretinal interface.
- To compare MLC density and distribution in patients with and without posterior vitreous detachment (PVD).
Main Methods:
- Optical Coherence Tomography Angiography (OCT-A) was used to image the macula in 21 eyes (11 without PVD, 10 with PVD).
- Repeated, registered, and averaged foveal-centered 3x3 mm OCT-A images were analyzed.
- MLCs were detected in the OCT slab from 0 to 3 microns above the internal limiting membrane.
- MLC density and distribution were calculated in relation to the superficial vascular plexus (on-vessel, perivascular, and non-vascular areas).
Main Results:
- MLC density was significantly higher (1.8-fold) in the PVD group compared to the no PVD group (P=0.04).
- MLC counts showed a trend towards increase in all analyzed regions in eyes with PVD.
- MLC density was not substantially reduced after PVD, indicating they are unlikely to be predominantly vitreal hyalocytes.
Conclusions:
- The findings suggest that the majority of MLCs at the vitreoretinal interface are not vitreal hyalocytes.
- Posterior vitreous detachment status is a significant factor to consider in future studies investigating MLCs.
