Surface structure of rabbit and human retina after enzymatic separation of inner limiting membrane.

In order to investigate the structure of the retina without the overlying inner limiting membrane (ILM), the ILM was separated from the retina in rabbit and human specimens by enzymatic digestion with matrisolve and trypsin. Human specimens were taken from the area between the optic disc and the fovea, while rabbit specimens were taken from 5 mm below the medullary ray. The rabbit specimens were immersed and digested in 0.05% trypsin, while the human specimens were immersed and digested in crude matrisolve. Digestion was carried out before fixation. The structure of the denuded retina without the overlying ILM was observed by scanning electron microscopy (SEM) following enzymatic digestion. In both the human and rabbit specimens, the ILM appeared to be a structure that was independent from the retina. The surface of the denuded retina appeared to be covered with Müller cell footplates, which appeared in cobblestone arrangement in rabbit specimens and in mosaic arrangement in human specimens. Adhesion between the ILM and the retina seemed to be maintained by a biochemical matrix that was digested by proteinases, in both rabbit and human specimens.