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. Transudation of fluid through the RPE defects causes detachment of the otherwise normal sensory retina. As the fluid shifts with eye and head movements, the involved portion of the retina changes. This explains why most patients with ERDs suffer significantly less devastating visual compromise than those with RRDs or TRDs.
Tractional detachments occur only in proliferative vitreoretinopathies.
The most common of these is proliferative diabetic retinopathy, but many TRDs are associated with ischemic retinal vein occlusions, sickle cell retinopathy, retinopathy of prematurity, toxocariasis and trauma. The etiology of TRD involves fibrotic scaffolding of the vitreous along proliferative vascular networks which induce strong anterior tractional forces through vitreal shrinkage. Unlike rhegmatogenous or exudative detachments which tend to be abrupt, TRDs are often slow and insidious, progressing at the same rate as the associated fibrovascular proliferation. Peripheral TRDs are therefore rarely if ever noticed by the patient. Macular TRDs, on the other hand, tend to be symptomatic, unless the underlying disease process has already compromised visual acuity.