Microanatomy of vitreoretinal interactions in macular and paramacular areas

Aim. To refine microanatomy of vitreoretinal interactions in central areas of retina and to obtain additional information on vitreoretinal interactions regarding theoretical possibility of collagen synthesis in the vitreous body of adult humans and mechanisms of vitreoretinal adhesion. Methods. Scanning electron microscopy study was performed in central areas of human retina after removal of vitreous base from its surface. Results. On the surface of retina we found a thin layer of epiretinal vitreous body most strongly bound to the retina. Thickness of paramacular epiretinal vitreous is 3–5 µm and it is formed mainly by thin densely packed fibrils. Its surface layer facing the vitreous cavity consists of the thickest (1 µm) and longest (250 µm) fibrils loosely packed. These fibrils look like “pearl threads” and exhibit signs of newly formed fibrils. Epiretinal layer of the vitreous in the fovea is thinner, its thickness is about 2 µm. Top layer of fibrils is least densely packed with the thickness of the fibrils of about 0.2 µm. The closer to internal limiting membrane, the thinner the fibrils, the denser their packing. The discovered layer can be interpreted as an additional anatomic structural unit of the vitreous body — epiretinal vitreous. Conclusion. We detected indirect signs of lifetime synthesis of newly formed fibrils in the vitreous of adult human; newly formed collagen may be localized in epiretinal vitreous which may be the main binding component providing vitreoretinal adhesion.