Aqueous Humor Formation
MECHANISM OF AQUEOUS HUMOR FORMATION
There is a constant flow of aqueous humor through the anterior segment of the eye. The aqueous is formed by the ciliary process and flows from the posterior chamber to anterior chamber through the pupil and exits the eye at the angle. The secretion of aqueous humor generates the intraocular pressure required for an optically efficient globe. The flow of aqueous provides nutrition for the avascular ocular tissues that it bathes, the posterior surface of the cornea, trabecular meshwork, crystalline lens and anterior vitreous.The volume of the aqueous in the anterior chamber turns over approximately once every 100 minutes.This constant flow of aqueous replenishes nutrients that have been taken up by the avasculat tissues and carries away their metabolic wastes.The factors that determine the the IOP is given by the Goldmann equation. P0 =F/C+Pv
Where P0 is the IOP, F is the rate of aqueous humor formation in (l/min, C is the facility of outflow in (l/min/mmHg and Pv is the episcleral venous pressure in mmHg
SITE OF FORMATION OF AQUEOUS HUMOR
The precise location of aqueous humor production appears to be predominantly in the anterior portion of the pars plicata along the tips or crests of the ciliary processes, since this region has been shown to have
a).increased basal and lateral interdigitations, mitochondria and rough endoplasmic reticulum in the non-pigmented ciliary epithelium
b).more numerous fenestrations in the capillary endothelium
c).thinner layer of capillary stroma and
d).an increase in all organelles and gap junctions between pigmented and non-pigmented epithelia
When Sodium fluroscein is administered systemically and the ciliary body is absorbed with a special gonioprism, fluroscein stained aqueous is seen primarily at the tips of the ciliary process.
The site of active transport is considered to be the non-pigmented epithelial cells,
There is a constant flow of aqueous humor through the anterior segment of the eye. The aqueous is formed by the ciliary process and flows from the posterior chamber to anterior chamber through the pupil and exits the eye at the angle. The secretion of aqueous humor generates the intraocular pressure required for an optically efficient globe. The flow of aqueous provides nutrition for the avascular ocular tissues that it bathes, the posterior surface of the cornea, trabecular meshwork, crystalline lens and anterior vitreous.The volume of the aqueous in the anterior chamber turns over approximately once every 100 minutes.This constant flow of aqueous replenishes nutrients that have been taken up by the avasculat tissues and carries away their metabolic wastes.The factors that determine the the IOP is given by the Goldmann equation. P0 =F/C+Pv
Where P0 is the IOP, F is the rate of aqueous humor formation in (l/min, C is the facility of outflow in (l/min/mmHg and Pv is the episcleral venous pressure in mmHg
SITE OF FORMATION OF AQUEOUS HUMOR
The precise location of aqueous humor production appears to be predominantly in the anterior portion of the pars plicata along the tips or crests of the ciliary processes, since this region has been shown to have
a).increased basal and lateral interdigitations, mitochondria and rough endoplasmic reticulum in the non-pigmented ciliary epithelium
b).more numerous fenestrations in the capillary endothelium
c).thinner layer of capillary stroma and
d).an increase in all organelles and gap junctions between pigmented and non-pigmented epithelia
When Sodium fluroscein is administered systemically and the ciliary body is absorbed with a special gonioprism, fluroscein stained aqueous is seen primarily at the tips of the ciliary process.
The site of active transport is considered to be the non-pigmented epithelial cells,