vitreous humour(redirected from base of vitreous)
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vitreous humourA transparent, colourless gel which occupies the stroma of the vitreous body. The vitreous humour is secreted by the ciliary body processes, which provides nutrition to the lens; the aqueous humour passes through the pupil, leaves by the trabecular meshwork and Schlemm’s canal, and passes into the aqueous veins.
The vitreous humour is of forensic interest, because the in vivo serum levels of alcohol, drugs and other substances can be estimated from the vitreous humour—e.g., at equilibrium, the ratio of blood alcohol concentration (BAC) to vitreous humour alcohol concentration (VHAC) is 0.81, with the caveat that estimating the BAC based only on vitreous humour (i.e.,without blood) is unscientific.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
vitreous humourthe liquid jelly-like material occupying the space within the eyeball behind the lens of the eye.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
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.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann