The consistency and viscosity of the vitreous body seem to depend to a large extent upon the structure of the fibrous network formed by the so-called residual protein, which, on the basis of most recent evidence, can be assumed to be represented by fibers of collagen or material closely related to collagen.* Recent studies by various authors have shown that the formation and physiochemical properties of collagen fibers can be significantly influenced by certain strongly polarized substances, among which is an acid mucoprotein found in blood plasma.3 The carbohydrate moiety of this mucoprotein shows essentially the same composition as the neutral mucopolysaccharides attached to all serum plasma globulin,4 and the acid nature of the mucoprotein resides with the protein moiety.
It has been found by several authors that the isolated fibrous material of the vitreous contains a significant amount of carbohydrate bound to the protein of the fiber.
DISCHE Z, ZELMANES G. Polysaccharides of the Vitreous Tibers. AMA Arch Ophthalmol. 1955;54(4):528-538. doi:10.1001/archopht.1955.00930020534005