Retinal detachment
Separation of the neurosensory retina from the underlying retinal pigment epithelium cuts off its blood supply and causes progressive, painless visual field loss, a surgical emergency where speed of treatment determines whether central vision is saved.
First principles
The disease is a physical separation of two retinal layers, not a vascular or inflammatory process
The neurosensory retina sits against, but is not fused to, the retinal pigment epithelium beneath it; the two layers are held together mainly by vitreous pressure and active fluid pumping by the pigment epithelium. In rhegmatogenous detachment, the most common type, a retinal tear (usually from vitreous traction as the vitreous shrinks and separates with age) lets liquefied vitreous fluid track behind the retina, physically peeling it off the pigment epithelium. Once separated, the neurosensory retina loses its blood and nutrient supply from the underlying choroid, and its photoreceptors stop working.
Educational content pending clinical review. Not medical advice.