• During rhegmatogenous retinal detachment, two major phagocytic cell populations can be identified in the subretinal fluid. Routine light and electron microscopic studies may be inadequate to assess quantitatively the free-floating retinal pigment epithelial cells and the macrophagic retinal pigment-laden cells. Enzyme histochemical staining permits a simple, rapid, reproducible method of identifying each cell type. This cytologic biochemical differentiation is an important tool for reexamination of the theories associated with subretinal fluid cell activity.
Feman SS, Lam K. An Enzyme Histochemical Analysis of Human Subretinal Fluid. Arch Ophthalmol. 1978;96(1):129-131. doi:10.1001/archopht.1978.03910050085022