aqueous humour


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Related to aqueous humour: vitreous humour

aqueous humour

The watery fluid filling the front chamber of the eye between the back of the CORNEA and the front of the IRIS.

aqueous humour

fluid that fills the space between the cornea and the lens of the vertebrate EYE (see Fig. 156 ).

humour, aqueous

Clear, colourless fluid that fills the anterior and posterior chambers of the eye. It is a carrier of nutrients for the lens and to a larger extent the cornea, especially of glucose and essential amino acids. It contributes to the maintenance of the intraocular pressure. It is formed in the ciliary processes, flows into the posterior chamber, then through the pupil into the anterior chamber and leaves the eye through the trabecular meshwork passing to the canal of Schlemm and then to veins in the intrascleral venous plexus (Fig. H3). A small amount (10% to 15%) also flows out of the eye via the uveoscleral pathway. The aqueous in the anterior chamber is a component of the optical system of the eye. It has an index of refraction of 1.336, slightly lower than that of the cornea, so that the cornea/aqueous surface acts as a diverging lens of low power. It is a fluid very similar to blood plasma but with a much lower concentration of protein and a higher concentration of ascorbate.The rate of aqueous humour outflow varies between 2.0 μl/min and 3.0 μl/min via both the conventional (trabecular meshwork and Schlemm's canal) and the unconventional (uveoscleral) pathways. This rate is normally equal to the rate of aqueous secretion. If the rate of outflow is lower than the rate of secretion intraocular pressure increases. See aqueous flare; ultrafiltration.
Fig. H3 Outflow of aqueous humourenlarge picture
Fig. H3 Outflow of aqueous humour
References in periodicals archive ?
According to Pravin N Soni et al, they have observed that there is a remarkable difference in sodium concentration of aqueous humour in turn and this can be one of the important risk factors in the formation of cataract.
But how exactly do these cytokines manifest in the aqueous humour of DR patients is not clear.
Aqueous humour is constantly produced in the eye and it exits through the space between the iris and the cornea, called the drainage angle, so it's in constant circulation.
The uveoscleral route drains only 10% of the aqueous humour. Imagining the eye as a washbasin, the amount of fluid in the eye depends on the rate of aqueous secretion and the rate of aqueous outflow.
Contraction of the ciliary muscle produces traction on the trabecular meshwork, facilitating aqueous humour drainage and lowering IOP [6].
It is believed that the aqueous humour has lytic properties and inhibits the subconjunctival fibroblasts [21,22], leading to persistent leakage of the filtering bleb [20].
The human eye's conventional outflow pathway consists of aqueous humour passing through the trabecular meshwork (TM) and into Schlemm's canal (see Figure 1).
Evisceration of ocular contents (right eye) include lens, iris and aqueous humour in a doe was treated successfully by tarsorrhaphy and surgically managed.
The transplants improved the quality of the trabecular meshwork tissue, boosting the aqueous humour outflow and protecting the retinal ganglion cells, according to the paper published in the journal PNAS.
frequently culminate in loss of eye vision as a result of endophthalmitis, anterior chamber collapse and glaucoma or chronic leakage of aqueous humour, leading to atrophy of ciliary body and phthisis bulbi (Felberg, 2003).
THEY will be clowning around at the Lantern eatre this weekend when the venue hosts the two-day Aqueous Humour workshop event.