All retinal detachments involve the sensory retina dissecting from the underlying pigment epithelial layer by subretinal fluid. In rhegmatogenous detachments, this fluid is liquefied vitreous, which accesses the subretinal space via a retinal break. In exudative detachments, the fluid is derived from the choroid, passing through a defective Bruch's membrane. The origin of the subretinal fluid in tractional detachments is unknown. Both passive and active movement of subretinal fluid induce progression of retinal detachments, leading to partial or total loss of vision in some patients.
Retinal breaks are the predisposing factor in patients with rhegmatogenous detachment.
These may result from preexisting conditions or ocular trauma. Some of the more common entities associated with RRD include lattice degeneration, flap tears, atrophic holes, operculated retinal breaks, and acquired retinoschisis with both inner and outer holes. As the retinal tissue loses its connection to the RPE, it becomes edematous and dysfunctional. Without surgical intervention, death of this tissue occurs within 48 to 72 hours. Exudative detachments are relatively rare, occurring in association with subretinal disorders that damage the RPE layer.