Table 3.

Summary of Key Studies Highlighting the Role of Myeloid Cells in Ischemic Retinopathies

Study	Model	Species	Outcomes and measures
Acute ischemic retinopathy
Wagner et al. (2021) [99]	IR	Rat	Microglial activation enhances pro-inflammatory cytokines accompanied by TLR signaling 2 h post-IR (p = 0.028)
Abcouwer et al. (2021) [75]	IR	Mouse	Myeloid leukocyte accumulation 14 days post-IR (p ≤ 0.001)
Tang et al. (2020) [82]	IR	Mouse	Elevated Iba1+ cells numbers in retina 1-day post-IR (p < 0.001)
Fouda et al. (2018) [46]	IR	Mouse	Myeloid arginase 1 deletion exacerbates loss of retinal neurons (p < 0.05) and thinning of the retina at 7 days post-IR (p < 0.05)
Ahmed et al. (2017) [73]	IR	Mouse	Increased number of IBA1+ cells/mm in GCL at 1-day post-IR (p ≤ 0.0001)
Sanchez et al. (2003) [108]	IR	Rat	Increased expression of IL-6 by microglia/macrophages at 2 h post-IR (p < 0.05)
Diabetic retinopathy
Huang et al. (2023) [118]	SIDR	Mouse	Retinal microglia necroptosis promotes neuroinflammation in the early stages of diabetic retinopathy
Park et al. (2021) [116]	SIDR	Rat	Increased Iba1+ retinal microglia density in diabetic mice compared to control mice (p < 0.05)
Atawia et al. (2020) [115]	WDIDR	Mouse	Arginase 2 (A2) deletion inhibits retinal microglia activation (p < 0.05)
Mendiola et al. (2016) [124]	Ins2Akita	Mouse	Recombinant fractalkine reduces perivascular microglial clustering (p < 0.01)
Cardona et al. (2015) [123]	Ins2Akita	Mouse	Retinal microglia increase in diabetic mice (p < 0.05)
Rangasamy et al. (2014) [121]	SIDR	Rat	CCL2 activates retinal microglia and attenuates vascular leakage and infiltration of monocytes
Krady et al. (2005) [117]	SIDR	Rat	Microglia activate in the early stages of diabetic retinopathy
Pathological retinal angiogenesis
Liu et al. (2022) [156]	OIR	Mouse	Localization of microglia near pathological neovascular tufts (p < 0.001)
Liu et al. (2022) [138]	OIR	Mouse	Macrophage depletion by clodronate increases neovascularization on P12 (p < 0.05)
Zhou et al. (2022) [135]	OIR	Mouse	Microglial depletion suppresses pathological neovascularization (p < 0.05)
He et al. (2021) [119]	OIR	Mouse	Microglia necroptosis largely ablates retinal angiogenesis
Liu et al. (2020) [142]	OIR	Mouse	Arginase-1 transcript is elevated in microglia/macrophages (p < 0.001)
Villacampa et al. (2020) [144]	OIR	Mouse	Depletion of myeloid-cell specific Vhl stabilizes HIFs and stimulates retinal revascularization (p < 0.05; p < 0.001)
Zhu et al. (2017) [133]	OIR	Mouse	M2 macrophage polarization genes are upregulated on P13-P24 (p < 0.05)
Gao et al. (2016) [136]	OIR	Mouse	Macrophage depletion by clodronate reduces percentage of neovascular area (p < 0.01)
Zhou et al. (2015) [134]	OIR	Mouse	Bone marrow-derived M2 macrophages increase pathological neovascularization (p < 0.01)
Dejda et al. (2014) [146]	OIR	Mouse	NRP-1+ myeloid cells are recruited to neovascularization sites in the retina
Zhou et al. (2015) [134]	OIR	Mouse	Bone marrow-derived M2 macrophages increase pathological neovascularization (p < 0.01)
Kataoka et al. (2011) [137]	OIR	Mouse	Depletion of native vitreal macrophages reduces neovascularization (p < 0.01)
Human ischemic retinopathy
Ong et al. (2021) [149]	DR	Human	Increased density of macrophage-like cells in PDR compared to healthy patients (p < 0.05)
Zeng et al. (2008) [150]	DR	Human	Microglial cells were observed to cluster around veins in the GCL, microaneurysms, and retinal and vitreal neovascularization

CCL2: Monocyte chemoattractant protein-1, DR: Diabetic retinopathy, FABP5: Fatty acid-binding protein 5, GCL: Ganglion cell layer, HIF: Hypoxia-inducible factor, IR: ischemia reperfusion, NRP-1: Neuropilin-1, OIR: Oxygen-induced retinopathy, PDR: proliferative diabetic retinopathy, PKM2: enzyme pyruvate kinase M2, SIDR: Streptozotocin-induced diabetic retinopathy, TLR: Toll-like receptor, Vhl: Von Hippel-Lindau tumor suppressor protein, WDIDR: Western-diet induced retinopathy