Macular pucker. II. Ultrastructure.

Twenty symptom-producing epimacular membranes removed during vitreous surgery were examined by light microscopy, scanning and transmission electron microscopy. These membranes contain cells of glial and pigment epithelial origin, but one also finds myofibroblasts and fibroblasts which cannot be identified morphologically as to their origin. The membranes can be classified into two types. Membranes in one group are composed of numerous alternating layers of collagen and cells and some internal limiting lamina. The second type of membrane is generally composed of a single layer of cells with large sheets of internal limiting lamina from the retinal surface and little if any collagen. Both types of membranes have cells on the retinal side of the removed internal limiting lamina, presumably derived from neurosensory retina.