Unveiling the P2X7 receptor: Exploring its mechanisms, pathogenic role in ocular diseases, and emerging therapeutic potential.

Purinergic signaling, mediated by extracellular ATP (eATP) and P2 receptors, plays a vital role in physiological and pathological processes. The P2X7 receptor (P2X7R), a ligand-gated cation channel, is crucial in inflammation, cell death, and immune responses. Widely expressed in retinal cells, P2X7R contributes to visual function regulation and retinal degeneration. This review explores P2X7R involvement in retinal diseases, including age-related macular degeneration (AMD), Behçet's disease (BD), diabetic retinopathy (DR), glaucoma, retinitis pigmentosa (RP), uveitis, Stargardt's disease (STGD), and toxoplasmosis. P2X7R activation drives inflammation, oxidative stress, apoptosis, and immune dysregulation. For instance, it contributes to RPE degeneration in AMD, vascular proliferation in DR, neuroinflammation in glaucoma, and photoreceptor loss in RP. In uveitis, P2X7R enhances Th1 and Th17 responses. Targeting P2X7R with antagonists or modulators holds therapeutic potential, offering strategies to preserve retinal function and prevent vision loss in these debilitating diseases.