anatomy of anterior chamber angle , aqueous production and drainage and its clinical co-relation

1. ANATOMY OF ANTERIOR CHAMBER
ANGLE, AQUEOUS PRODUCTION AND
DRAINAGE AND ITS CLINICAL CO-
RELATIONS
Moderator Presenters
Dr.Sanjeeev Bhattarai Aayush Chandan
Anita Poudel
9/22/2018
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2. PRESENTATION LAYOUT
 Introduction to Anterior Chamber
 Angle structures and their identification
 Grading of chamber angles
 Abnormalities in AC
 Aqueous production and drainage system
 IOP measurement
 Clinical co-relations
Glaucoma
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3. ANTERIOR CHAMBER
 Potential space in the anterior segment of
eye
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4.  Bounded anteriorly by:
-Corneal endothelium
 Bounded peripherally by:
-Trabecular meshwork(portion of
ciliary body) & Iris root
 Bounded Posteriorly by:
-Anterior iris surface & pupillary
area of anterior lens
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5. DIMENSIONS OF ANTERIOR CHAMBER
 Volume : 220 µl
 Average depth : 3.15mm(2.6-4.4mm)
-center is deeper than periphery
-deeper in aphakia,pseudophakia &
myopia
-shallower in hyperopia
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6. POSTERIOR CHAMBER
 Triangular in shape
 Contains 0.06ml of aqueous
 Bounded -anteriorly by posterior surface of iris &
part of ciliary body
-posteriorly by crystalline lens & zonules
-laterally by ciliary body
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8. ANTERIOR CHAMBER ANGLE
 Structure forming angle recess(from posterior to
anterior)
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Ciliary band
Scleral spur
Trabecular
meshwork
Schwalbe’s line

9. 1.CILIARY BAND
 Marks the posteriormost part of the
angle.
 Represents the anterior face of ciliary
body between its attachment to the
scleral spur & insertion of iris.
 Width depends on the level of iris
insertion.
 Wide in myopes & narrow in
hypermetropes
 Dark or brown band
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10. 2.SCLERAL SPUR
 Wedge shaped circular ridge
 Pale,translucent narrow strip of
scleral tissue
 Composed of group of fibres
called “scleral roll”
 Scleral roll is composed of 75-
85% collagen & 5% lastic tissue
 Appear as prominent white line
on gonioscopy.
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11. 3.TRABECULAR MESHWORK
 Sieve like structure made up of connective
tissue lined by trabeculocytes,which have
contractile & phagocytic properties.
 Main function is in drainage of aqueous
humor
 Roughly triangular in cross section with apex
towards schwalbe’s line & base is formed by
the scleral spur & ciliary body
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 No pigment at birth but develops with increasing
age
 Morphologically & functionally divided into 3 types:
Uveal meshwork , Corneo-scleral meshwork &
Juxta-canalicular meshwork

13. CLINICAL SIGNIFICANCE
 Steroid-Induced glaucoma
Steroid and glucocorticoids increases the
expression of ECM protein fibronectin, GAGs , elastin
& laminin within the TM cells which leads to increased
trabecular meshwork resistance resulting in elevated
IOP
 In laser trabeculoplasty, burns are applied to the
junction between pigmented and nonfunctional
trabecular meshwork
 Some pathological conditions can cause
increased pigmentation:
Pseudoexfoliation syndrome
Pigment dispersion syndrome
Neovascular glaucoma
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14. 4.SCHWALBE’S LINE
 Anterior limit of drainage angle
 Seen as fine scalloped border at the termination of
descemet’s membrane of cornea
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15.  Prominance of
Schwalbe’s line is known
as Posterior embryotoxon
, seen in Axenfield
Reiger’s Anomaly
 Pigments along
Schwalbe’s line are
known as Sampaolesi’s
line , seen in Pigmentary
glaucoma &
Pseudoexfoliation
syndrome
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16. IMPORTANCE OF ANGLE OF AC
 For classification of glaucoma
 To assess angle recession
 History or evidence of inflammation
 To note the extent of neovascularization
 For evidence of neoplastic activity
 Degenerative or developmental anomaly
 For planning of treatment-Iris
neovascularization & laser procedure
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17. ANGLE ESTIMATION DIAGNOSTIC
MODALITIES
Iris shadow test
Van herick test
Smith’s test
Split limbal technique
OCT
Ultrasound biomicroscopy
Gonioscopy
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18. 1.IRIS-SHADOW TEST
 Depth of AC can be evaluated by focusing a beam
of light on the temporal limbus , parallel to the
surface of iris
 In case of deep AC , the iris lies flat & the whole iris
will be illuminated
 In case of very shallow AC , the iris lies forward ,
blocking some of the light & very little of the iris is
illuminated.
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19.  Based on the amount of eye illuminated the AC
depth can be graded
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21. 2.VAN HERICK TEST
 Common quantitative methods of assessing
the size of ACA using the slit lamp
biomicroscope
 A narrow slit of light is projected onto the
peripheral cornea at an angle 60° a near as
possible to limbus
 This results in a slit image on the surface of
the cornea(SC) , the width of which is used
as reference for the assessement of
chamber angle
 The width of the chamber angle can be
described by the distance between corneal
slit image & the slit image on the iris
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22. Grade Relation between corneal
thickness and anterior
chamber depth
Interpretation
4 1 : 1 or higher Angle closure very unlikely;
Chamber angle approx.
35°to 45°
3 1 : ½ Angle closure unlikely;
Chamber angle approx.
20°… 35°
2 1 : ¼ Angle closure possible;
Chamber angle approx. 20°
1 1 : < ¼ Angle closure likely;
Chamber angle approx. 10°
0 Closed Angle closure; Chamber
angle approx. 0°
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25. 3.SMITH’S METHOD
 Quantitative method of measuring the ACD , using
the slit lamp biomicroscope with the observation
system directly in front of pt’s eye & illumination
system at an angle of 60º to the temporal side
 A beam of approx. 1.5mm thickness , with its
orientation horizontal is placed across the cornea
 A second beam is then seen in the plane of
crystalline lens
 The length of beam is adjusted until the beam on
the cornea & crystalline lens just appear to meet
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26.  The length of beam is read directly from the slit
lamp & this no. is multiplied by 1.34 to calculate
ACD
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27. 4.SPLIT LIMBAL TECHNIQUE
 To estimate the superior & inferior angles by the
use of slit lamp
 With the illumination in the position , a vertical slit
should be placed across the superior ACA at 12
O’clock
 Observe the arc of light falling on the cornea & iris
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28. 5.OPTICAL COHERENCE
TOMOGRAPHY(OCT)
 Uses low coherence
interferometry to obtain
cross-sectional images of the
ocular structure
 To image the anterior
segment , longer wavelength
light is used
 Anterior segment OCT can
be used to take measurement
of the angle
 4 quadrants can be scanned
at once
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29. 6.ULTRASOUND BIOMICROSCOPY
 Close contact ( non-invasive)
immersion technique
 UBM is perfomed with the pt.supine ,
positioning that theoretically cause
the iris diaphragm to fall back. This
deepens the AC & opens the angle
 With UBM , only 1 quadrant can be
imaged at a time.
 There is risk of infection or corneal
abrasion d/t contact nature of
examination
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30. 7.GONIOSCOPY
 The gold standard for ACA assesement
 Use of a slit lamp & gonio-lens
 Allow direct visualization into the ACA
 To carry out gonioscopy , the cornea is
anaesthesized using topical anaesthetic
 With gonioscopy any abnormalities within the
angle(e.g;pigment deposition,neovascular growth
etc.) can be detected.
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31.  All gonioscopy lenses eliminate the tear-air
interface placing a plastic or glass surface adjacent
to the front of the eye
 Methods of gonioscopy :
1)Direct
 2)Indirect
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32. DIRECT GONIOSCOPY : PROCEDURE
 Most easily perfomed with the pt. supine & in the
operating room for an examination under anesthesia
with 4% xylocaine.
 Performed using a direct goniolens & either a binocular
microscope or a slit-pen light
 The lens is positioned after saline or viscoelastic is
placed on the eye, which can act as a coupling device.
 The lens provides direct visualization of the chamber
angle in an erect position
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33.  Direct goniolenses
koeppe
barkan
Swan-jacob
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34. INDIRECT GONIOSCOPY : PROCEDURE
 Perfomed under the slit lamp
 Pt. and examiner nust be positioned in a comfortable
position
 A drop of topical anesthetic is then applied to the
conjunctiva of both eyes.
 If using the goldmann lens , contact gel is placed in the
concave part of the lens
 If using a posner or similar type lens , a drop of artificial
tears can be placed on the concave surface
 Pt. is then asked to open both eyes and look upwards.
 Examiner can then pull down slightly on the lower lid
and places the lens on the surface of the eye
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35.  Pt.is then asked to look straight
ahead
 Most examainers choose to start
with the inferior
Angle as it is usually more open
and the pigmentation if the
trabecular meshwork is slightly
more prominent , allowing for
easier identification of the angle
structures.
o Continue identifying all angle
structure in all 4 quadrants , and
then repeat with the other eye
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36. Indirect goniolenses :
Goldmann
zeiss
sussman
posner
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37. GOLDMANN LENS
 It is three mirror contact lens
 For examination of the entire
ocular fundus and the iridocorneal
angle.
 The advantage of a longer mirror is
that it often permits binocular
observation of the lateral sections
of the ocular fundus
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38. Observations:
 Central(1) – posterior pole
 73 ° mirror (2) – equator
 67 ° mirror (3) – ora serrata
 59 ° mirror (4) – iridocorneal angle
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39.  The structure visible in a wide angle are(from iris to
cornea)
a)ciliary band (CP)
b)scleral spur (SS)
c)Trabecular Meshwork (TM)
d)schwalbe’s line (SL)
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40. SHAFFER’S GRADING
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42. PHYSIO-CHEMICAL PROPERTIES
 volume : 0.31ml (0.25ml in AC & 0.06ml in PC)
 Refractive index : 1.336
 Density : slightly greater than water
 Viscocity : 1.025-1.040
 Osmotic pressure : slightly hyperosmotic to plasma
by 3-5mOsm/l
 PH : 7.2
 Rate of formation : 2-2.5µl/min
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43. BIOCHEMICAL PROPERTIES
 Water : 99.9%
 Proteins ( colloid content) : 5-16 mg/100ml
 Amino Acids : aqueous/plasma concentration varies
from 0.08-3.14
 Non-colloidal constituents : concentration of
ascorbate , pyruvate , lactate in higher amount
while urea & glucose are much less
 Inulin & steroid
 Prostaglandins
 Cyclic AMP
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44. FUNCTIONS
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• Inflates the globe
• Maintain structural integrity
IOP
maintenance
• Provides nourishment to
cornea lens & retinaMetabolism
• Clear optical medium for vision
• Acts as diverging lens of low
power
Optical
function
• Serves to clear blood ,
macrophages, remnants of
lens matter from AC
Clearing
function

45. ABNORMALITIES IN AC
1.HYPHEMA
 Blood in AC
 May appear as reddish tinge or it may
appear as a small pool of blood of the
iris or in the cornea
 Usually due to trauma , may be a/w
neovascularization of iris or angle , iris
lesions or malposition of IOL
 Total hyphema is also known as “8-
ball” or “Black ball”
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46. 2.HYPOPYON
 Pus in AC
 Usually d/t Inflammation(Uveitis,Bechet Disease
etc)
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47. 3.CELLS
 Appear as small particles floating in aqueous
 May be WBCs, RBCs or pigment cells
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48. GRADING OF AQUEOUS CELL
Grade Cells in field
- Less than one cell
+/- One to five cell
+1 Six to fifteen
+2 Sixteen to twenty-five
+3 Twenty-six to fifty
+4 Greater than fifty
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49. 4.FLARE
 Appears as hazy cloudy aqueous
d/t severe fibrinous exudate
 Usually found in uveitis , trauma ,
postoperative scleritis & keratitis
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50. CLINICAL GRADING OF FLARES
Grade Description
0 No aqueous flare
+1 Faint(just detectable)
+2 Moderate flare with clear
iris & lens
+3 Marked flare(iris and flare
hazy)
+4 Intense flare(fibrin or
plastic aqueous
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51. 5.MOLTENO’S TUBE
 Is drainage device used to reduce
intraocular pressure in severe &
complex cases of glaucoma where
conventional drainage procedures
have failed or often little prospect of
success
 Usually a/w following signs
- previous trabeculectomy ,
neovascular glaucoma , iridocorneal
endothelial syndrome , advanced
glaucomatous disc.
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52. 6.SILICONE OIL IN AC
 Commonly used approach for retinal tamponade
during surgery in the vitreous or for retinal
reattachment surgery
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53. AQUEOUS PRODUCTION
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54. ANATOMY OF CILIARY BODY
 Anterior portion of uveal tract located
between iris & choroid
 Site of aqueous humor production
 Triangular in cross-section ; apex
contiguous with choroid & base close to
iris
 Anterior portion of ciliary body is k/a
Pars Plicata/Corona Ciliaris ,
characterized by Ciliary process
consisting of 70 radial ridges & equal
no. of smaller ridges
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55.  Pars plicata accounts for 25% of
total length of CB having Surface
area of 6cm2 for ultrafiltration &
active fluid transport,being actual site
of aqueous production
 Posterior portion is pars
plana/orbicularis ciliaris,relatively flat
& pigmented inner surface & is
continuous with choroid at ora
serrata
 Ciliary body is composed of muscle ,
vessels & epithelium
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56. CILIARY MUSCLES
 3 muscles fibers
Longitudinal muscle fiber:
Contraction opens Trabecular
meshwork & Schlemn’s canal
 b)Circular Muscle fiber :
Contraction relaxes zonules ,
↑ses lens axial diameter & its
convexity
Oblique Muscle fibers :
Contraction widen the uveal
trabecular Space
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57. CILIARY VESSELS
 The long posterior ciliary
artery(branch of ophthalmic
artery)along with anterior ciliary
arteries form the major arterial circle
to supply the ciliary body.
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Brimonidine , an α-adrenergic agonist commonly used for
glaucoma treatment , reduces aqueous formation by causing
vasoconstriction of ciliary arterial supply.

58. CILIARY EPITHELIUM
 Ciliary body is lined by
two layers of epithelium.
 Outer pigmented
epithelium composed of
low cuboidal cells &
continuous with retinal
pigment epithelium
 Inner non-pigmented
epithelium continuous
with Retina
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59. PHYSIOLOGY OF AQUEOUS PRODUCTION
 The aqueous humour is primarily derived from
plasma within capillary network of ciliary
processes.
 Three physiologic processes which contribute
to formation and chemical composition of
aqueous humour are:
1) Ultra-filtration
2) Active transport
3) Diffusion
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60. ULTRAFILTRATION
 Process by which fluids and its solutes crosses
semipermeable membrane under pressure gradient
 As blood passes through the capillaries of the ciliary
processes, about 4% of the plasma filters through the
fenestrations in the capillary wall into the interstitial
spaces between the capillaries and the ciliary
epithelium
 Water and water soluble substances,limited by size
and charge, flow into stroma of ciliary process from
capillaries
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61.  The high conc. of colloid in the tissue space of
ciliary processes favours the movement of water
from the plasma into the ciliary stroma but retards
the movements from ciliary stroma into posterior
chamber.
 latter requires active processes which occurs in
tandem with ultra-filtration
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62. ACTIVE TRANSPORT
 Active transport (secretion) is an energy-dependent
process that selectively moves a substance against its
electrochemical gradient across a cell membrane.
 majority of aqueous humor formation depends on an
ion or ions being actively secreted into the intercellular
clefts of the non-pigmented ciliary epithe-lium beyond
the tight junctions
 In the small spaces between the epithelial cells , the
secreted ion /ions create sufficient osmotic forces to
attract water.
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63.  Water soluble substances of larger size or greater
charge are actively transported across NPE
 The best current evidence suggests that the paired
Na/H and Cl/HCO transports Na/Cl from stroma into
the cell.
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64.  Main ions to be actively transported across NPE
include
 Sodium
 Chloride
 Bicarbonate
 Active transport of Na+ - key feature of aqueous
production
 role of aqua-porins in active transport of water
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65. 9/22/2018
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66. DIFFUSION
 Movement of substance across a membrane along
its concentration gradient .
As aqueous humour passes from PC to AC,
sufficient diffusional exchange with surrounding
tissues occur so that AC aqueous resembles
plasma more closely than posterior aqueous
humour.
Aqueous humour provides glucose, amino acids,
oxygen, and potassium to surrounding tissues and
removes carbon dioxide, lactate, and pyruvate.
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67. BLOOD AQUEOUS BARRIER
 The blood–aqueous barrier consists of all of the barriers
to the movement of substances from the plasma to the
aqueous humor
 formed by tight junctions between cells of NPE of ciliary
body and tight junctions of iris capillary endothelial cells
 In some situations (e.g., intraocular infection), a
breakdown of the blood–aqueous barrier is clearly
therapeutic because it brings mediators of cellular and
humoral immunity to the interior of the eye.
 In other situations (e.g., some forms of uveitis and
following trauma), the breakdown of the barrier is
inappropriate and favors the development of
complications, such as cataract and synechia formation.
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68.  This barrier is not absolute as medium sized water
soluble substances may penetrate it but at much
slower rate.
 Lipid solubility greatly facilitates ability of
substance to penetrate blood ocular barrier
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69. STEPS OF AQUEOUS FORMATION
 Active secretion → 70%
 Ultrafiltration →20% and
 Osmosis → 10%
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71. I. FORMATION OF STROMAL POOL
 First step
 By Ultrafiltration, most substances pass across stroma
between PE cells before accumulating behind tight
junctions of NPE cells
 Protein is left in filtrate because of fenestrated nature of
ciliary capillaries
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72. II. ACTIVE TRANSPORT OF STROMAL
FILTRATES
 The net effect of ion transport systems located in PE and
NPE are:
Low level of sodium in both epithelial layers
High level of potassium and ascorbate
Control of intracellular pH
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73. III. PASSIVE TRANSPORT ACROSS NON-
PIGMENTED CILIARY EPITHELIUM
 Active transport across non-pigmented ciliary epithelium
results in osmotic and electrical gradient
 To maintain balance of osmotic and electric forces, water,
chloride and other small plasma constituents move into
posterior chamber by Ultrafiltration and Diffusion
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74. AQUEOUS HUMOUR COMPOSITION
Substance Aqueous Plasma
(nmol/kg) humour
Na+ 163 176
Cl- 126 117
HCO3
- 22 26
PH 7.21 7.40
Ascorbate 0.92 0.06
Protein 0.02% 7%
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75. RATE OF AQUEOUS HUMOR FORMATION AND
MEASUREMENT TECHNIQUES
 Rate of aqueous humor formation of 2–3µl/min
 The techniques for measuring aqueous humor
formation can be divided into two major categories:
1) pressure-dependent methods
2) tracer methods
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76. Pressure dependent methods
(that use volumetric analysis of the
eye;)
Tracer methods
(tracer methods that monitor the
rate of appearance or
disappearance of various
substances from the eye.)
Tonography Fluorescein
Suction cup Paraminohippurate
Perfusion Iodide
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77. FACTORS AFFECTING AQUEOUS
HUMOR FORMATION
 Diurnal fluctuation : Aqueous flow is higher in the
morning than in the after-noon. The rate of aqueous
formation during sleep is approximately one-half the
rate upon first awakening
 Age and sex : appears to be similar in males and
females. There is a reduction in aqueous formation
with age (particularly after age 60).Decline in aqueous
production of about 3.2% per decade in adults
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78.  Intraocular pressure: Aqueous humor formation
increases or decreases to changes in IOP.
 Neural control : stimulation of the cervical
sympathetic chain decreases aqueous humor
production
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79. AGENTS THAT AFFECT AQUEOUS HUMOR
FORMATION
Adrenergic agonist Decreases
Pilocarpine Slightly increases
Quabain Decreses
Carbonic anhydrase inhibitor Decreases
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80. INTRA OCULAR PRESSURE
 Normal level of IOP maintained by a dynamic equilibrium
between aqueous humor formation, aqueous humor outflow and
episcleral venous pressure.
 Normal range of IOP: 15.5 ±2.57 mm of Hg
 IOP = Intraocular pressure,
 AHF = Aqueous humor formation,
 Fu = Uveoscleral outflow,
 Ctrab = Facility of outflow from the anterior chamber via the
TM and Schlemm’s canal,
 Pe = Episcleral Venous Pressure
IOP = [(AHF - Fu ) /Ctrab ] + Pe
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81. Acute increase in IOP Chronic increase in IOP Decreased
IOP
Acute angle closure
glaucoma
Primary open angle
glaucoma
Ruptured globe
Inflammatory open-
angle glaucoma
Phthisis bulbi
Suprachoroidal
hemorrhage
Retinal/choroidal
detachment
Hyphema Iridocyclitis
Retrobulbar
hemorrhage
Severe dehydration
Ocular ischemia
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82. AQUEOUS DRAINAGE SYSTEM
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83.  Aqueous Drainage System includes:
Trabecular Meshwork
Schlemm’s Canal
Collector Channels
Episcleral Veins
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84. ANATOMY OF OUTFLOW SYSTEM:
I.Trabecular Meshwork
 Sieve like structure through which aqueous humor
leaves the eye
 Bridges the scleral sulcus and converts it into a tube
which accommodates the Schlemm’s Canal
 Allows the bulk flow aqueous out of the anterior
chamber but prevents blood reflux into anterior
chamber.
 Hence, forms the crucial part of normal blood-
aqueous barrier
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85.  Trabecular Meshwork consists of three
portions namely:
Uveal Meshwork
Corneo-scleral
Meshwork
Juxta-canalicular
Meshwork
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86. 9/22/2018
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87. TRABECULAR MESHWORK (CONTD.)
1) UVEAL MESHWORK
 Innermost part of trabecular meshwork, extends from iris
root and ciliary body to Schwalbe’s line
 2 to 3 layers thick
 Opening size 25µ to 75µ
 On electron microscopy each trabeculae is seen to have
concentric layers:
 Central collagenous core
 Middle basement membrane
 Outer trabecular cells
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88. TRABECULAR MESHWORK (CONTD.)
2) Corneo-scleral Meshwork
• Larger middle portion extending from scleral spur
to lateral wall of scleral sulcus
• Consists of flat sheets of trabeculae with elliptical
openings ranging from 5µ to 50µ
• Openings are progressively smaller as they
approaches schlemm’s canal.
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89. TRABECULAR MESHWORK (CONTD.)
3) Juxta-canalicular Meshwork
• Outermost portion of trabecular meshwork
• It mainly offers resistance to normal aqueous outflow
• This narrow part of trabeculum connects corneo-scleral
meshwork with Schlemm’s Canal.
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90. II. SCHLEMM’S CANAL
 Endothelial lined oval channel present
circumferentially in the scleral sulcus
 The endothelial cells of inner wall are irregular,
spindle shaped and contains giant vacuoles
 The endothelial cell of outer wall are smooth and
flat containing numerous opening of collector
channels.
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91.  Canal is located directly anterior to scleral spur and
is normally not seen.
 Blood in canal is more common under conditions of
elevated episcleral venous pressure,uveitis or
scleritis
 Hypotony may also cause blood to reflux into the
canal.
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92. C) COLLECTOR CHANNELS
 Also k/a Intrascleral Aqueous Vessels
 25 to 35 in number
 Leave Schlemm’s Canal at oblique angles to
terminate ultimately into episcleral veins
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93.  Consists of two systems namely:
a. Direct System
 drained by about 8 larger vessels
 drain directly into episcleral veins
 Also known as Aqueous Veins or Laminated
Veins of Goldmann
b. Indirect System
 Constituted by fine interconnecting channels
before eventually entering into episcleral veins
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94. D) EPISCLERAL VEINS
 Most of the aqueous vessels drain into episcleral
veins.
 Episcleral veins ultimately drain into cavernous
sinus via anterior ciliary and superior ophthalmic
veins.
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95. 9/22/2018
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96. PHYSIOLOGY OF DRAINAGE OF
AQUEOUS HUMOR
 Aqueous Humour is clear relatively cell free, protein
free fluid, formed by the ciliary body epithelium in
posterior chamber
 Passes between iris and lens to enter anterior
chamber through pupil
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97. THERMAL CURRENTS IN ANTERIOR
CHAMBER
 In anterior chamber, aqueous is subjected to thermal
currents because of temperature difference between
vascular and warmer iris and avascular and cooler
cornea
 Cornea is cooler compared to iris because of the cooling
effect of tear,due to its evaporation
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98.  Exits the eye at anterior chamber angle via two
pathways:
I. Conventional Trabecular Pathway
II. Unconventional Uveo-scleral Pathway
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99. I. CONVENTIONAL TRABECULAR
PATHWAY
 About 75 to 90% of aqueous is drained via this route into
episcleral veins
 Circulatory path for aqueous humor return to the
vascular system
 Free Flow from trabecular meshwork upto
Juxtacanalicular meshwork, along with inner wall of
Schlemm’s Canal, offer some resistance to the flow and
hence helps in maintaining relatively stable IOP
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100. II. UNCONVENTIONAL UVEOSCLERAL
PATHWAY
 Approximately 10 to 25% of total aqueous drained via
this pathway
 The main resistance to uveoscleral flow is by tone of the
ciliary muscle
 Factors like Pilocarpine that contracts ciliary muscle
lower the uveoscleral outflow
 Whereas, the factors such as atropine that relax ciliary
muscle raise the uveoscleral flow
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101.  Aqueous Humor enters ciliary muscle through uveal
trabecular meshwork, ciliary body face and iris root
 Passes posteriorly between bundles of ciliary
muscle until it reaches supra ciliary and
suprachoroidal spaces
 Leaves eye through spaces around penetrating
nerves and blood vessels through sclera
Venous
Circulat
ion
Supra-
choroid
al
Space
Across
Ciliary
Body
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102.  Uveoscleral drainage is possible only beacause of
pressure gradient of 2-4 mm of hg between
suprachoraoidal space and aqueous chamber
 This pressure difference may be reversed with age
or trabeculectomy causing choroidal effusion.
Clinical Correlation
Prostaglandins used to reduce IOP in various
conditions including glaucoma reduce IOP by
increasing the aqueous drainage via this pathway.
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103. Ciliary processes
AQ IN POSTERIOR CHAMBER
Aq in anterior chamber
Trabecular Meshwork
Schlemn’s canal
Collector channels
Episcleral veins
Ciliary body
Suprachoroidal space
Venous circulation of ciliary body,
choroid and sclera
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104. 9/22/2018
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105. TRABECULAR MESHWORK AND SCHLEMM’S
CANAL ENDOTHELIAL CELLS
 Specialized characters:
• Active phagocytic properties
• High levels of cytoskeletal actin
• Lower levels of microtubules
Presence of desmin and vimentin shows
similarity to smooth muscle cells
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106. CLASSIFICATION OF GLAUCOMA
1) Congenital/ developmental glaucoma
2) Primary adult glaucoma
Primary open angle glaucoma(POAG)
Primary angle closure glaucoma(PACG)
3) Secondary glaucoma
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107. PRIMARY ANGLE CLOSURE
GLAUCOMA
Defining criterias:
o Irido-trabecular contact noted in gonioscopy(>270)
o PAS is formed
o IOP is elevated (> 24 mmHg)
o Optic disc shows glaucomatous changes as POAG
o Visual fields shows typical glaucomatous changes.
Pathogenesis:
o Pupillary block mechanism
o Plateau iris configuration and syndrome
Pushing of peripheral iris forward by ciliary process.
o Phacomorphic mechanism
Abnormal lens position
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108. PIGMENT DISPERSION SYNDROME/
PIGMENTARY GLAUCOMA
 Pigment dispersion refers to a pathologic increase in the
TM pigment, associated with characteristic mid-
peripheral, radial iris TIDs.
 The pigment may ultimately obstruct the TM, leading to
increased IOP and secondary open-angle glaucoma.
 Pigment release is caused by mechanical rubbing of
post surface of iris with zonular fibrils
Clinical features
 Mid-peripheral, spokelike iris TIDs
 Deposition of pigments in ant segments as iris,
posterior surface of cornea
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109.  Deposition of pigments in ant segments as iris,
posterior surface of cornea
 Dense homogeneous pigmentation of the TM for
360 degrees (seen on gonioscopy) in the absence
of signs of trauma or inflammation.
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110. NEOVASCULAR GLAUCOMA
Formation of neovascular m/m involving the angle of
AC
a/w neovascularization of iris (rubeosis iridis)
PDR
CRVO
Sickle cell retinopathy
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111. REFERENCES
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Thank you