Background: Retinal ischemia–reperfusion (RIR) injury refers to an obstruction in the retinal blood supply followed by reperfusion. Although the molecular mechanism underlying the ischemic pathological cascade is not fully understood, neuroinflammation plays a crucial part in the mortality of retinal ganglion cells. Methods: Single-cell RNA sequencing (scRNA-seq), molecular docking, and transfection assay were used to explore the effectiveness and pathogenesis of N,N-dimethyl-3β-hydroxycholenamide (DMHCA)-treated mice with RIR injury and DMHCA-treated microglia after oxygen and glucose deprivation/reoxygenation (OGD/R). Results: DMHCA could suppress inflammatory gene expression and attenuate neuronal lesions, restoring the retinal structure in vivo. Using scRNA-seq on the retina of DMHCA-treated mice, we provided novel insights into RIR immunity and demonstrated nerve injury-induced protein 1 (Ninjurin1/Ninj 1) as a promising treatment target for RIR. Moreover, the expression of Ninj1, which was increased in RIR injury and OGD/R-treated microglia, was downregulated in the DMHCA-treated group. DMHCA suppressed the activation of the nuclear factor kappa B (NF-κB) pathways induced by OGD/R, which was undermined by the NF-κB pathway agonist betulinic acid. Overexpressed Ninj1 reversed the anti-inflammatory and anti-apoptotic function of DMHCA. Molecular docking indicated that for Ninj1, DMHCA had a low binding energy of − 6.6 kcal/mol, suggesting highly stable binding. Conclusion: Ninj1 may play a pivotal role in microglia-mediated inflammation, while DMHCA could be a potential treatment strategy against RIR injury.

Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has been increasingly implicated in selected ocular diseases, although its causal relevance varies across disease entities. The retina and retinal pigment epithelium are biologically susceptible to ferroptosis-related injury because of their high oxygen demand, abundant polyunsaturated lipids, mitochondrial activity, light exposure, and tightly regulated iron handling. This review summarizes core mechanisms of ocular ferroptosis, including iron uptake and export, glutathione–glutathione peroxidase 4 (GPX4)-dependent antioxidant defense, lipid peroxidation, mitochondrial dysfunction, neuroinflammation, and blood–retina barrier disruption. We discuss evidence from major degenerative, vascular, ischemic, hereditary, infectious, and immune-mediated retinal diseases, with particular attention to glaucoma, age-related macular degeneration, diabetic retinopathy, ocular toxoplasmosis, uveitis, retinal vasculitis, and inflammatory chorioretinopathy. We also evaluate ferroptosis-targeted therapeutic strategies, proposed operational criteria for defining ferroptosis in retinal disease, and candidate structural, functional, biochemical, and imaging endpoints for future translational studies. Current evidence supports ferroptosis as a context-dependent contributor to retinal injury rather than a uniform pathogenic mechanism. Future studies should integrate cell-type-resolved biomarkers, lipidomic and imaging readouts, functional rescue experiments, and clinically meaningful visual outcomes to clarify when ferroptosis modulation may support vision preservation.