Aqueous Humour

Question 1

What is the Aqueous Humour?

Answer 1

A thin watery fluid that fills the space between cornea and lens. can be found in both posterior and anterior chambers. Secreted specifically and continually by non pigmented epithelium of ciliary body. It flows through narrow cleft between back of iris and front of lens to escape through pupil into anterior chamber, it will leave the eye via trabecular meshwork.
Needs to have4 a balanced rate of production and rate of drainage or will have a large influence on intraocular pressure. pressure measured in Hg

Question 2

Functions of Aqueous Humour

Answer 2

• Brings oxygen and nutrients to cells of lens, cornea and iris
• Removes products of metabolism and toxic substances from lens, cornea and iris.
• Provides and optically clear medium for vision
• Maintains IOP

Question 3

Blood Aqueous Barrier

Answer 3

Barrier responsible for the differences in composition between plasma and aqueous
Sometimes a breakdown of barrier can be clearly therapeutic but sometimes after trauma etc can lead to complications

Question 4

Trabecular Meshwork

Answer 4

Trabecular meshwork is a triangular porous structure , in cross section consist of connective tissue surrounded by endothelium. TB passes over scleral sulcus and converts it into a circular channel, called canal of Schlemm.
can be divided into 3 components- uveal- conrneosvleral, juxtacanicular.

Question 5

Aqueous Drainage pathways

Answer 5

leaves eye by two pathways at anterior chamber angle -

• conventional or trabecular route= through the TM across the inner wall of the canal of schlemm into its lumen,drain into episclera venous system-70 to 95% of aqueous outflow.
• unconventional or uveoscleral route- across iris route, uveal meshwork, anterior surface of ciliary muscle and out through sclera. - 5 to 30% of outflow by this way