Retinal blood vessel permeability

Retinal blood vessel permeability refers to the physiological state and functional integrity of the blood-retinal barrier (BRB), which prevents the unregulated passage of fluids, proteins, and lipids from the systemic circulation into the neural retina (Nature Reviews Disease Primers, 2021; PMC, 2021). Maintenance of low permeability is critical for preserving the highly controlled microenvironment necessary for visual phototransduction and preventing tissue edema (PMC, 2021). In pathological states such as diabetic retinopathy (DR) and neovascular age-related macular degeneration (nAMD), various stressors—including hyperglycemia and hypoxia—trigger the upregulation of pro-permeability factors, most notably vascular endothelial growth factor A (VEGF-A) (MDPI, 2024; JCI, 2004). These factors disrupt endothelial tight junctions by promoting the phosphorylation and internalization of proteins like occludin and claudins, leading to barrier breakdown (UCL Discovery; PMC, 2021). Therapeutically, reducing retinal blood vessel permeability is a primary clinical goal, typically achieved through the administration of anti-VEGF biologics, such as ranibizumab and aflibercept, or intraocular corticosteroids (MDPI, 2024; Guidechem, 2024).

Other names

Retinal vascular permeabilityBlood-retinal barrier breakdownRetinal vascular leakageRVPBlood-retinal barrier permeability

The primary therapeutic mechanism involves the neutralization of pro-permeability growth factors (primarily VEGF-A and Ang-2) and the activation of corticosteroid receptors to stabilize endothelial tight junctions, reduce inflammatory cytokine release, and restore the blood-retinal barrier's integrity.