INTRODUCTIONThe clear fluid filling the space in front of the eyeball between lens and cornea.The aqueous humour supplies nutrition and removes waste from the clear structure in the anterior eye(cornea and lens)The balance between aqueous production and outflow determines the intraocular pressure. INTRODUCTION The clear fluid filling the space in front of the eyeball between lens and cornea. The aqueous humour supplies nutrition and removes waste from the clear structure in the anterior eye(cornea and lens) The balance between aqueous production and outflow determines the intraocular pressure.

1. AQUEOUS HUMOUR
(PRODUCTION AND DRAINAGE)
PRESENTER – FARHANA JAFRI
MODERATOR – MR. JAYANT JHA

2. AQUEOUS HUMOUR
 INTRODUCTION
• The clear fluid filling the space in front of the eyeball between
lens and cornea.
• The aqueous humour supplies nutrition and removes waste
from the clear structure in the anterior eye(cornea and lens)
• The balance between aqueous production and outflow
determines the intraocular pressure.

3. OCULAR STRUCTURES RELATED TO AQUEOUS
HUMOUR
• Ciliary body
• Posterior chamber
• Anterior chamber
• Angle of the anterior chamber
• Aqueous outflow system

4. CILIARY BODY
• It is the site of aqueous humour production.
• It is the forward continuation of the choroid at ora serrata.

5. POSTERIOR CHAMBER
• It is a triangular space containing about 0.06 ml of aqueous
humour production.
• It is bounded:
• Anteriorly by the posterior surface of iris and part of ciliary
body.
• Posteriorly by the crystalline lens and its zonules.
• Laterally by the ciliary body.

6. ANTERIOR CHAMBER
• It is the fluid-filled space inside the eye between the iris and
the cornea(endothelium).
• It is about 3 mm deep in normal adult.
• It contains about 0.25 ml of the aqueous humour production.
• It is filled by the clear fluid called aqueous humour.

7. ANTERIOR AND POSTERIOR CHAMBER

8. ANGLE OF THE ANTERIOR CHAMBER
• The peripheral recess of anterior chamber is called angle of
anterior chamber.
• It is formed by the trabecular meshwork.
• It plays an important role in aqueous humour drainage.

9. STRUCTURE FORMING ANGLE RECESS
1. CILIARY BAND
• It is the most posterior landmark in the angle recess.
• It appears as a grey or dark brown band.
2. SCLERAL SPUR
• It is the posterior portion of the scleral sulcus.
• It is usually appear as a prominent white line on gonioscopy.

10. CONT…
3. TRABECULAR MESHWORK
• It is seen as a band just anterior to the scleral spur.
• With age, its colour varies from faint tan to dark brown.
4. SCHWALBE’S LINE
• It is a fine ridge seen just in front of the trabecular meshwork.

11. GONIOSCOPIC GRADING OF THE ANGLE
WIDTH
• Shaffer’s system of grading shows the angle width:

12. AQUEOUS OUTFLOW SYSTEM
It includes:
1. Trabecular meshwork
2. Schlemm’s canal
3. Collector channel
4. Episcleral vein

13. CONT…
1. TRABECULAR MESHWORK
• It is sieve-like structure through which aqueous humour leave
the eye.
• It bridges the scleral sulcus and convert it into a tube, which
accommodate schlemm’s canal.
2. SCHLEMM’S CANAL
• It is an endothelial lined oval channel.
• It is present in the scleral sulcus.

14. CONT…
3. COLLECTOR CHANNELS
• These are also called intrascleral aqueous vessels.
• It leave the schlemm’s canal at oblique angles to terminate
ultimately into Episcleral vein.
4. EPISCLERAL VEINS
• Most of the aqueous vessels drain into the Episcleral vein.

15. PHYSIOCHEMICAL PROPERTIES
1. Volume:- 0.31 ml (0.25 ml in anterior chamber and 0.06 ml in
posterior chamber).
2. Refractive Index:- 1.336
3. Osmotic Pressure:- 3-5 mOsm/l.
4. pH:- 7.2
5. Rate Of Formation:- 2.3 µl /min.

16. FUNCTIONS OF AQUEOUS HUMOUR
• It maintains the intraocular pressure (IOP).
• It provides nutrition to cornea, lens, vitreous humour and
retina.
• It removes harmful substances such as lactic acid and carbon
dioxide.
• It provides optically clear medium for vision.

17. FORMATION OF AQUEOUS HUMOUR
• Aqueous humour is produced from pars plicata part of ciliary
body through ciliary processes.
• Aqueous humour is derived from plasma within the capillary
network of the ciliary processes.
• Three physiologic processes contribute to the formation of
aqueous humour:
1. Diffusion
2. Ultrafiltration
3. Secretion

18. CONT…

19. 1. DIFFUSION
• Diffusion is the movements of substance across
semipermeable membrane along concentration gradient.
• As aqueous humour passes from the posterior chamber to
Schlemm’s canal, it is in contact with ciliary body, iris, lens,
vitreous, cornea and trabecular meshwork.
• In the process of aqueous production, the lipid soluble
substances are transported by diffusion through the lipid
portion of the cell membrane of the ciliary processes.

20. CONT…

21. 2. ULTRAFILTRATION
• The process by which fluid and its solutes cross
semipermeable membrane under pressure gradient is called
ultrafiltration.
• It refers to occurrence of dialysis under hydrostatic pressure.
• In the process of aqueous formation, water and water-soluble
substances flow through the protein part of the cell membrane
in response to hydrostatic pressure.

22. CONT…

23. 3. SECRETION (ACTIVE TRANSFER)
• Secretion implies an active process that selectively transports
some substances across the cell membrane.
• It is postulated that majority of aqueous humour formation
depends on active transport.
• It is done by non-pigmented epithelial cells.
• This mechanism is mediated by globular proteins in the
membrane and requires the expenditure of energy.

24. DRAINAGE OF AQUEOUS HUMOUR
• Aqueous flow from posterior to anterior chamber through
pupil.
• From anterior chamber, the aqueous is drained out by two
routes:
1. Trabecular (conventional) outflow
2. Uveoscleral (unconventional) outflow

25. FLOWCHART OF AQUEOUS HUMOUR
DRAINAGE

26. CONT…

27. 1. TRABECULAR OUTFLOW
• The major drainage structure for aqueous humour are the
conventional or trabecular outflow pathway.
• 75-90 % of the total aqueous is drained through this route.
• It is comprised of the trabecular meshwork (made by uveal
and corneoscleral meshwork), the juxtacanalicular connective
tissue (JCT), schlemm’s canal, collector channels and Episcleral
vein.
• The TM outflow pathway is critical in providing resistance to
aqueous humour outflow and in generating intraocular
pressure (IOP).

28. CONT…
• Free flow of aqueous occurs from the trabecular meshwork in
the angles of anterior chamber upto juxtacanalicular tissue.
• It along with the inner wall of the Schlemm’s canal appears to
provide some resistance to the outflow.

29. 2. UVEOSCLERAL OUTFLOW
• The uveoscleral outflow is responsible for 10-25 % of the total
aqueous humour outflow.
• Aqueous passes across the ciliary body into the
suprachoroidal space.
• It is drained by the venous circulation in the ciliary body,
choroid, sclera and into the orbital tissues.
• Uveoscleral outflow is approximately 0.3 ml.

30. CONT…
• The uveoscleral outflow is decreased by contraction and
increased by relaxation of the ciliary muscles.
• Prostaglandins may decrease the intraocular pressure by
increasing the uveoscleral outflow.
• Two mechanisms seem to contribute to this effect: relaxation
of the ciliary muscle and changes in extracellular matrix,
causing decreased resistance in the uveoscleral outflow
routes.

31. REFERENCE
• ANATOMY AND PHYSIOLOGY 3rd EDITION
(AK KHURANA)
• GOOGLE

32. THANK YOU