Subretinal fluid in primary rhegmatogenous retinal detachment: physiopathology and composition

During retinal detachment, subretinal fluid is present, whose composition and physiopathology are still little known. Under normal conditions, osmotic and oncotic pressures help keep the retina in place, but the main retinal attachment force is provided by active transport in the pigment epithelium. Subretinal fluid composition varies according to detachment duration; total protein concentration in subretinal fluid increases with time. In addition, all proteins are qualitatively modified. The detached retina loses its oxygen supply, and it then uses the anaerobic pathway to degrade glucose. Thus, long-duration retinal detachments feature increased lactic acid and dextrose concentrations. Phospholipids are also increased in subretinal fluid, reflecting retinal degradation. This review presents data on the physiopathology and composition of the subretinal fluid in retinal detachments.