The vitreous body is a component of the eye's refractive system and provides support, shock absorption, and metabolic functions for surrounding structures such as the lens and retina. It consists of approximately 98% water and 0.15% macromolecules, including collagen, hyaluronic acid, and soluble proteins. The remaining solid substances include ions and low-molecular-weight compounds. Its two main structural components are type II collagen, which forms a fine fibrous network, and hyaluronic acid, a glycosaminoglycan interwoven within the collagen framework.
Under normal conditions, the vitreous body exists in a gel-like state, with a slow metabolic rate and no regenerative capacity. It exhibits properties such as plasticity, viscoelasticity, and resistance to compression. With increasing age, the collagen fiber scaffold of the vitreous may collapse or shrink, leading to vitreous liquefaction and posterior vitreous detachment.