what is the angle of anterior chamber?
- angle between the posterior cornea & anterior iris surface
- function
> for outflow of aqueous humour (drainage of aqueous) - structure related to the angle
> trabecular meshwork
> schlemm’s canal
> scleral spur
dynamics of aqueous humour
Normal IOP results from a dynamic balance between the rate of aqueous production into the posterior chamber and aqueous drainage from the anterior chamber.
aqueous humour production
three(3) mechanism of aqueous formation
- diffusion
- ultrafiltration
- active transport
aqueous humour drainage (conventional pathway)
- accounts for 90% of aqueous production
- through trabecular mesh work
- schlemm’s canal
- ~25 collector channels
- aqueous veins
- episcleral veins & anterior ciliary veins to mix w blood
aqueous humour drainage (unconventional pathway)
- accounts for 10% of aqueous drainage
- starts from anterior surface of ciliary body
- suprachoroidal space
- vortex veins/venous circulation (venous drainage)
- into the ciliary body, choroid & sclera
normal IOP values
average
- 15.5mmHg
normal range
- 10-21mmHg
abnormal IOP
- Abnormal IOP results if the balance between the rate of aqueous production and rate of aqueous drainage is disturbed.
- This may indicate a pathology, such as glaucoma.
general arrangement of vitreous humour
- A transparent gel that fills the space between the lens and retina.
- The vitreous is attached to the following parts of the eye:
> posterior lens surface
> ora serrata
> para-vascular areas
> para-macula area
> optic disc
purpose of vitreous humour
The vitreous is in contact with the retina, and keeps the retina in place by pressing against the choroid.
age-related change in vitreous humour
With age, the vitreous undergoes degeneration
- Develops pockets of fluid and shrinks away from the retina, cause vitreous detachment
