Changes in macrophage-like cells characterized by en face optical coherence tomography after retinal stroke

Abstract

PurposeThe retina could serve as a window of neuroinflammation, but the in vivo changes in macrophage-like cell (MLC), such as microglia, in acute ischemic retinal stroke remain unclear. Thus, the current study aimed to investigate the in vivo changes in MLC characterized by en face optical coherence tomography (OCT) after acute ischemic retinal stroke.MethodsTwenty patients with unilateral acute nonarteritic reperfused central retinal artery occlusion (CRAO) were participated in this study, and their contralateral eyes served as control group. A 3 μm en face OCT slab on the inner limiting membrane of the optic nerve head (ONH) region or macular region was used to visualize and binarize the MLCs. The MLCs were binarized and quantified using a semiautomated method. OCT angiography was used to evaluate the reperfusion status and obtain the structural data of the inner retina in the ONH and macula. The thickness of the ganglion cell complex in the macular region was measured. The optical intensity and optical intensity ratio of the inner retina were calculated to evaluate the ischemia severity.ResultsIn the ONH region, decreased vessel densities of radial peripapillary capillaries accompanied by increased thickness of the retinal nerve fiber layer were found in the CRAO eyes in comparison to the unaffected eyes (p=0.001, p=0.009, respectively). In the macular region, significantly lower vessel densities in both the superficial and deep capillary plexus and increased thickness of the ganglion cell complex were also found in the CRAO eyes (all p ≤ 0.001). The ONH and macular MLC quantities and densities in CRAO eyes were significantly higher than those in the unaffected eyes (both p<0.001). Larger and plumper MLCs were observed in the CRAO eyes compared with their unaffected eyes. ONH and macular MLC densities were positively associated with the disease duration in the acute phase and the optical intensity ratio of inner retina.ConclusionsThe increased density and morphological changes of MLCs may indicate the aggregation and activation of MLCs following acute reperfused CRAO. The aggregation of MLCs may be more pronounced in CRAO eyes with longer disease duration and more severe ischemia. MLCs characterized by en face OCT may serve as an in vivo visual tool to investigate neuroinflammation in the ischemic-reperfusion process of stroke.

Retinal OCT findings in acute central retinal artery occlusion of varying severity at different disease stages – a retrospective, observational study

“…As a result, the ILM is unsupported, resulting in an ILMD [ 9 , 23 ]. There is an increase in reactive oxygen radicals and proinflammatory macrophage like cells in the retinal tissue during reperfusion injury, which can be identified as hyperreflective dots in the inner retinal layers, sub-ILM space, or posterior cortical vitreous [ 9 , 24 , 25 ]. Increased inflammation following retinal reperfusion may result in the breakdown of the inner blood retinal barrier, causing fluid accumulation in the retinal layers as cystoid macular edema or in the subretinal space as neurosensory detachment [ 26 , 27 ].…”

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.…”

Immunological Landscape of Retinal Ischemia-Reperfusion Injury: Insights into Resident and Peripheral Immune Cell Responses

“…MLCs consist of microglia, perivascular macrophages, MDMs, and hyalocytes from the vitreous. Increased density and morphological changes of MLCs were observed after acute retinal ischemia-reperfusion [168,169]. After acute RIRI in CRVO, The increased density and morphological changes of MLCs may suggest the aggregation and activation of MLCs, which are correlated with the disease course and the ischemic severity [169].…”

“…Increased density and morphological changes of MLCs were observed after acute retinal ischemia-reperfusion [168,169]. After acute RIRI in CRVO, The increased density and morphological changes of MLCs may suggest the aggregation and activation of MLCs, which are correlated with the disease course and the ischemic severity [169]. Moreover, macrophage activation following acute RIRI was found to have detrimental effects on the health of endothelial cells in the retina [170].…”