vitreous humour

humour, vitreous

A transparent, colourless, gelatinous mass of a consistency somewhat firmer than egg white which fills the space between the crystalline lens, the ciliary body and the retina, and constitutes four-fifths of the volume of the eye. The vitreous is about 99% water, the remaining 1% includes hyaluronic acid, organic salts and soluble and insoluble proteins especially collagen (mainly type II). It is firmly attached to the pars plana of the ciliary body near the ora serrata in an area known as the vitreous base and around the optic disc. In older people and in pathological conditions the vitreous is no longer in a gel state, tending to become fluid. Syn. vitreous body. See hyaloid artery; asteroid hyalosis; floaters; hyaloid remnant; synchisis scintillans; Wagner's syndrome; vitreous base; vitreous detachment.