Anterior Chamber : Anatomy , Aqueous Production & Drainage

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 4/12/2018 1

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 4/12/2018 2

3. Anterior Chamber Potential space in the anterior segment of eye 4/12/2018 3

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 4/12/2018 4

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 4/12/2018 5

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 4/12/2018 6

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8. Anterior chamber angle Structure forming angle recess(from posterior to anterior) 4/12/2018 8

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 4/12/2018 9

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 . 4/12/2018 10

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 4/12/2018 11

12. 4/12/2018 12 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 : P seudoexfoliation syndrome Pigment dispersion syndrome Neovascular glaucoma 4/12/2018 13

14. 4.schwalbe’s line Anterior limit of drainage angle Seen as fine scalloped border at the termination of descemet’s membrane of cornea 4/12/2018 14

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 P igmentary glaucoma & P seudoexfoliation syndrome 4/12/2018 15

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 4/12/2018 16

17. Angle estimation diagnostic modalities Iris shadow test Van herick test Smith’s test Split limbal technique OCT Ultrasound biomicroscopy Gonioscopy 4/12/2018 17

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. 4/12/2018 18

19. Based on the amount of eye illuminated the AC depth can be graded 4/12/2018 19

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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 4/12/2018 21

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° Closed Angle closure; Chamber angle approx. 0° 4/12/2018 22

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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 4/12/2018 25

26. The length of beam is read directly from the slit lamp & this no. is multiplied by 1.34 to calculate ACD 4/12/2018 26

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 4/12/2018 27

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 4/12/2018 28

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 4/12/2018 29

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. 4/12/2018 30

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 4/12/2018 31

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 4/12/2018 32

33. Direct goniolenses koeppe barkan Swan- jacob 4/12/2018 33

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 4/12/2018 34

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. Continue identifying all angle structure in all 4 quadrants , and then repeat with the other eye 4/12/2018 35

36. Indirect goniolenses : Goldmann zeiss sussman posner 4/12/2018 36

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 4/12/2018 37

38. Observations: Central(1) – posterior pole 73 ° mirror (2) – equator 67 ° mirror (3) – ora serrata 59 ° mirror (4) – iridocorneal angle 4/12/2018 38

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) 4/12/2018 39

40. Shaffer’s grading 4/12/2018 40

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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 P H : 7.2 Rate of formation : 2-2.5µl/min 4/12/2018 42

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 4/12/2018 43

44. Functions 4/12/2018 44

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” 4/12/2018 45

46. 2.hypopyon Pus in AC Usually d/t Inflammation( Uveitis,Bechet Disease etc ) 4/12/2018 46

47. 3.cells Appear as small particles floating in aqueous May be WBCs, RBCs or pigment cells 4/12/2018 47

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 4/12/2018 48

49. 4.flare Appears as hazy cloudy aqueous d/t severe fibrinous exudate Usually found in uveitis , trauma , postoperative scleritis & keratitis 4/12/2018 49

50. Clinical grading of flares Grade Description 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 4/12/2018 50

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. 4/12/2018 51

52. 6.Silicone oil in AC Commonly used approach for retinal tamponade during surgery in the vitreous or for retinal reattachment surgery 4/12/2018 52

53. Aqueous production 4/12/2018 53

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 4/12/2018 54

55. Pars plicata accounts for 25% of total length of CB having Surface area of 6cm 2 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 4/12/2018 55

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 4/12/2018 56

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. 4/12/2018 57 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 4/12/2018 58

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 4/12/2018 59

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 4/12/2018 60

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 4/12/2018 61

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. 4/12/2018 62

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. 4/12/2018 63

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 4/12/2018 64

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66. Diffusion M ovement 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 . 4/12/2018 66

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. 4/12/2018 67

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 4/12/2018 68

69. Steps of Aqueous Formation Active secretion → 70% Ultrafiltration →20% and Osmosis → 10% 4/12/2018 69

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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 4/12/2018 71

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 4/12/2018 72

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 4/12/2018 73

74. Aqueous humour composition Substance A queous Plasma ( nmol /kg) humour Na + 163 176 Cl - 126 117 HCO 3 - 22 26 PH 7.21 7.40 Ascorbate 0.92 0.06 Protein 0.02% 7 % 4/12/2018 74

75. rate of aqueous humor Formation and measurement techniques R ate 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 4/12/2018 75

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 4/12/2018 76

77. Factors affecting aqueous humor Formation D iurnal 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 4/12/2018 77

78. I ntraocular pressure : Aqueous humor formation increases or decreases to changes in IOP. N eural control : stimulation of the cervical sympathetic chain decreases aqueous humor production 4/12/2018 78

79. Agents that affect aqueous humor formation Adrenergic agonist Decreases Pilocarpine Slightly increases Quabain Decreses Carbonic anhydrase inhibitor Decreases 4/12/2018 79

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, F u = Uveoscleral outflow, C trab = Facility of outflow from the anterior chamber via the TM and Schlemm’s canal, P e = Episcleral Venous Pressure IOP = [(AHF - F u ) / C trab ] + P e 4/12/2018 80

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 4/12/2018 81

82. Aqueous Drainage System 4/12/2018 82

83. Aqueous Drainage System includes: 4/12/2018 83

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 4/12/2018 84

85. Trabecular Meshwork consists of three portions namely: 4/12/2018 85

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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 4/12/2018 87

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. 4/12/2018 88

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 . 4/12/2018 89

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. 4/12/2018 90

91. C anal 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. 4/12/2018 91

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 4/12/2018 92

93. Consists of two systems namely: Direct System drained by about 8 larger vessels drain directly into episcleral veins Also known as Aqueous Veins or Laminated Veins of Goldmann Indirect System Constituted by fine interconnecting channels before eventually entering into episcleral veins 4/12/2018 93

94. d) Episcleral veins Most of the aqueous vessels drain into episcleral veins. E piscleral veins ultimately drain into cavernous sinus via anterior ciliary and superior ophthalmic veins . 4/12/2018 94

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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 4/12/2018 96

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 4/12/2018 97

98. Exits the eye at anterior chamber angle via two pathways: Conventional Trabecular Pathway Unconventional Uveo -scleral Pathway 4/12/2018 98

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 4/12/2018 99

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 4/12/2018 100

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 4/12/2018 101

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. 4/12/2018 102

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 4/12/2018 103

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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 4/12/2018 105

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 4/12/2018 106

107. PRIMARY ANGLE CLOSURE GLAUCOMA Defining criterias : Irido -trabecular contact noted in gonioscopy (>270) PAS is formed IOP is elevated (> 24 mmHg) Optic disc shows glaucomatous changes as POAG Visual fields shows typical glaucomatous changes. Pathogenesis: P upillary block mechanism Plateau iris configuration and syndrome Pushing of peripheral iris forward by ciliary process. Phacomorphic mechanism Abnormal lens position 4/12/2018 107

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 4/12/2018 108

109. D eposition 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. 4/12/2018 109

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 4/12/2018 110

111. references 4/12/2018 111 Thank you