secondary angle closure glaucoma

1. SECONDARY ANGLE
CLOSURE GLAUCOMA
SRISTI THAKUR
2ND YEAR RESIDENT
LEI, NAMS
1

2. CONTENTS
 Definition
 Mechanism
 Anterior pulling mechanism
 Posterior pulling mechanism
 Diagnosis
 Treatment
2

3. SECONDARY ANGLE CLOSURE GLAUCOMA
 Caused by impairment of aqueous outflow secondary to
apposition between the peripheral iris and the trabeculum.
 Related or identifiable ophthalmic condition is known to be
present with the onset of angle closure : “secondary” ACG
3

4. Two fundamental mechanisms:
 Anterior pulling mechanism:
peripheral iris pulled forward onto
TM by contraction of a membrane,
inflammatory exudate, or fibrous
band
 Posterior pushing mechanism:
peripheral iris is displaced forward by
lens, vitreous, or ciliary body
4

5. CLASSIFICATION
1. Anterior ‘pulling mechanism:
Contraction of an inflammatory, hemorrhagic, or vascular
membrane, band, or exudate in the angle
PAS
Forward displacement of lens-iris interface
Often accompanied by swelling and anterior rotation of ciliary body
5

6. ANTERIOR ‘PULLING MECHANISM
a. Neovascular glaucoma
b. Iridocorneal endothelial
syndromes (e.g. Chandler’s
syndrome)
c. Posterior polymorphous
dystrophy
d. Epithelial down growth
e. Fibrous ingrowth
f. Flat anterior chamber
g. Inflammation
6

7. NEOVASCULAR GLAUCOMA
Secondary glaucoma resulting from
neovascularization of anterior segment,
including iris and angle often
associated with retinal hypoxia.
SYNONYMS
1. Hemorrhagic glaucoma
2. Thrombotic glaucoma
3. Rubeotic glaucoma
4. Congestive glaucoma
5. Diabetic hemorrhagic glaucoma
9

8. NEOVASCULAR GLAUCOMA (NVG)
 Primary initiating events : hypoxia
and poor retinal capillary
circulation
 Begins as formation of new vessels
 Ends with fibrovascular membranes
migrating over drainage angle,
potentially leading to end-stage
glaucoma 10

9. HISTORY
1906  Coates , NVI in CRVO termed as RUBEOSIS IRIDIS
1937  Kurtz , NVA leading to PAS formation
1963  Weiss et al, coined the term NEOVASCULAR GLAUCOMA
11

10. 12

11. ETIOLOGY
Diabetic retinopathy (M.C.C)
CRVO/CRAO
Ocular ischemic disease
Carotid artery occlusive disease
• 36% cases : arise from CRVO
• 32% : proliferative diabetic
retinopathy
• 13% : carotid artery occlusive
disease 13

12. PATHOGENESIS
 Theory of angiogenesis factor:
 Michaelson 1948
Postulated existence of “X factor”, a vasoformative factor
which controlled development of new vessels
 Folkman et al
Isolated a soluble substance from a solid neoplasm capable
of producing neovascularisaton and popularised the term
“tumor angiogenesis factor”
16

13.  VEGF (Vascular endothelial growth factor)
 Potent angiogenic stimulator
 Has role in both normal and pathologic angiogenesis
 Also known as “vascular permeability factor” as induces
vascular hyperpermeability and endothelial cell
proliferation
 Four isoforms:
1. VEGF121
2. VEGF165 - most abundant form in most tissues
3. VEGF189
4. VEGF206
17

14.  Lens and vitreous acts as mechanical barriers and also releases
vaso inhibitory factors
 So any complicated cataract sx PCR, APHAKIA more
predisposition
 VEGF synthesised by all tissues in retina, mainly
MULLERS CELL.
 VEGF conc 50-100 times more in aqueous humour
in NVG
18

15. 19

16. Muller cells –primary source in conditions of retinal
ischemia
Retinal capillary or venous obstruction
Hypoxia of retinal cells
Production of vasoformative factor
Diffuses anteriorly
Stimulates iris angiogenesis
20

17.  Theory of vasoinhibitory factors (VIF):
 Source of VIF : Vitreous, lens and retinal pigment
epithelial cells
 Risk increased by vitrectomy and lensectomy
22

18. CLINICAL PRESENTATION
 Pain; Reduced vision
 Congested eye
 A/C reaction
 Elevated IOP < 40
mmHg
 Mid-dilated, non
reactive pupil
 Rubeosis irides (NVI)
 Neovascularization of
the angle (NVA)
 Ectropion uveae
23

19. Features Normal vessels New vessels
Location Iris stroma Pupillary margins
Angles
Arrangement Regular Irregular
Appearance Tortuous Thin
Course Radial Arbourising
Character Not fenestrated Fenestrated
Scleral spur Not cross Crosses
Flouroscein No leakage leakage
24

20. (A)Pre-glaucoma stage with new vessels appearing at pupillary margin
and in angle.
(B)Open-angle glaucoma stage with new vessels spreading and
fibrovascular tissue covering angle.
(C)Heavy neovascularization and extensive peripheral anterior
synechiae.
(D) Regression stage with angle sealed and vessels less visible
25
Stages of neovascular glaucoma.

21. DIAGNOSIS:
 Gonioscopy: vitally important to detect in early stage as NVA
can occur without NVI
 Strong association with CRVO
Treatment of choice
 Clear media : Panretinal photocoagulation
 Cloudy media
 Prevent laser therapy
 Panretinal cryotherapy - alternative to Vitrectomy to clear
the media with endophotocoagulation
 Or subsequent panretinal photocoagulation
 Anti -VEGF
33

22. IRIDOCORNEAL ENDOTHELIAL (ICE)
SYNDROME
 Group of disorders
characterized by abnormal
corneal endothelium
 Usually includes-
 iris atrophy
 corneal edema
 secondary angle-closure
glaucoma without pupillary
block
35

23. Cause:
Abnormal corneal endothelium forming a membrane over
anterior surface of iris and angle structures
Contraction of this membrane
Distorts iris and closes angle
36

24. In Variants:
 In early to mid adult life
 whites > blacks
 women > men
 U/L > B/L (fellow eye may have subclinical
abnormalities)
37

25. PATHOGENESIS
 Defect site: corneal endothelium – dysfunction corneal
edema
 Corneal endothelium elaborates a membrane contracts
forms PAS glaucoma
 Ischemia may be a secondary phenomenon ‘melt holes.’
 Few postulations:
 Abnormal proliferation of neural crest cells or a fetal crest of
epithelial cells
 Inflammatory endothelial proliferation
 Electron micrographic, immunohistochemical, and serologic
studies - herpes simplex virus and EBV as cause 38

26. 39

27. CLINICAL PRESENTATION
 PAS: extensive in quadrant toward which
pupil is displaced
 Thinner iris stroma in opposite quadrant to
PAS
 Full-thickness iris holes
 Anteriorly projected pigmented lesions
from iris surface with multilayered
membrane
40

28. THREE WELL CHARACTERIZED CLINICAL
ENTITIES
 Progressive iris atrophy
 Chandler’s syndrome
 Cogan-reese syndrome
41

29.  Slit-lamp: ‘beaten silver’
endothelium
 Specular reflection: loss of
the normal, regular
endothelial mosaic
 Specular microscopy:
alterations in size and shape
of endothelial
42

30. PROGRESSIVE (ESSENTIAL) IRIS ATROPHY
 Corectopia and ectopion uvea
(synechiae lift the iris off the surface
of the lens)
 Iris dissolution - patchy
disappearance of the stroma
progresses to full-thickness holes
 ‘stretch holes’
 ‘melt holes’
 Broad patchy PAS – extend ant to
schwalbe line
43

31. SYNDROM
E
- Most common variant
- Marked corneal changes
- Corectopia is minimal or absent
- Endothelium - hammered silver
appearance.
44

32.  Iris involvement - mild and limited to superficial stromal
dissolution.
 Peripheral anterior synechiae
- not diffuse
- do not extend as far anteriorly as in progressive iris atrophy
46

33. THE IRIS NAEVUS (COGAN–REESE)
SYNDROME
 diffuse naevus which covers the anterior iris or iris nodules .
 Iris atrophy - absent - 50% of cases
- remainder - mild to moderate although
corectopia may be severe.
47

34. TREATMENT
• Hypertonic solutions or soft contact lenses
• If corneal edema produces pain or reduced vision if IOP
is reduced - penetrating keratoplasty


Goniotomy- short term sucess
Filtering surgery or glaucoma drainage devices
49

35. POSTERIOR POLYMORPHOUS DYSTROPHY
 Disease of corneal endothelium sometimes associated
with glaucoma
 B/L
 Inheritence: autosomal dominant trait (AR also reported)
 Defect on: long arm of chromosome 20, three different
forms PPCD 1-3
50

36. HISTOPATHOLOGY
 Thin descemet’s membrane covered by multiple layers of
collagen
 Cell layers resembles endothelium, epithelium or
fibroblasts
 Some cases: membrane in angle and on anterior surface
of iris
51

37. PATHOGENESIS
 Cause -controversial
 Analogous to ICE syndrome
 Some postulates:
Dysplastic corneal endothelium produces BM-like material
Extends into angle Onto iris Contraction of
membrane Iris atrophy, corectopia, and iridocorneal
adhesions
 developmental disorder
 Viral infection (herpes simplex)metaplasia of the
corneal endothelium
52

38. CLINICAL PRESENTATION
 Variable
 Most typical physical finding: cluster
or linear arrangement of vesicles in
posterior cornea surrounded by a gray
haze
 Deep corneal stroma and DM :
 Band-like thickenings
 White patches
 Peau d’orange appearance
 excrescences projecting on AC
53

39.  Associated
 corneal edema
 iris atrophy
 mild corectopia
 iridocorneal adhesions
54

40.  Mostly non-progressive, asymptomatic
 Good vision throughout life
 Few cases: progressive corneal changes: corneal edema
 Glaucoma seen in 10–15%
 Differential diagnosis:
 Fuchs’ corneal dystrophy
 Congenital hereditary corneal dystrophy
 Axenfeld’s syndrome
 Congenital glaucoma:
55

41. TREATMENT
 Most : need no treatment
 For edematous cornea
 Hypertonic solutions
 Soft contact lenses
 Penetrating keratoplasty (as needed)
 glaucoma - medication
- filtering surgery
56

42. EPITHELIAL DOWNGROWTH
Pathophysiology
 Due to entry of epithelial membrane via wound
 Proliferation over corneal endothelium, TM, anterior iris
surface, and vitreous face
 Membrane in angle contracts
 PAS
 Severe angle-closure glaucoma without pupillary block
57

43. 58

44.  Most common cause - Cataract surgery (ICCE)
- penetrating keratoplasty
- glaucoma surgery
- penetrating trauma,
- unsuccessful removal of epithelial
cysts of anterior segment
59

45. CLINICAL PRESENTATION
 low-grade persistent
postoperative inflammation:
 conjunctival injection
 photophobia
 Cells in AC
 discomfort
 Evidence of current or past
wound leak
61

46.  Diagnostic finding: Hypotonic if
fistula is still functional
 Grayish white membrane with a
scalloped, thickened leading edge
on the posterosuperior corneal
surface.
 Cornea : edematous
 Iris: drawn up to old wound or
incision.
 Advanced cases:
 Painful eye with bullous
keratopathy and intractable
glaucoma 62

47. TREATMENT
 Difficult and unrewarding
 Techniques used are to close fistula and then to excise or
destroy epithelium
 For corneal portion of membrane: destroyed with cryotherapy
or chemical cauterization.
 Iris membrane: excised
 Cryotherapy applied to any remaining membrane on ciliary
body and retina
 En-bloc excision of all involved tissues 63

48. FIBROVASCULAR INGROWTH
 Occurs in an eye with open wound after penetrating
trauma or surgery
 Specially if associated with
 Hemorrhage
 Inflammation
 Incarcerated tissue
 Membrane is seen as interlacing pattern of gray
fibers(woven cloth)
64

49. Attributing factor:
 Invading fibroblasts to subconjunctival connective tissue,
corneal stroma, limbal tissue, metaplastic endothelium
Invading tissue grows over corneal endothelium, anterior
iris surface, vitreous face, and angle
Contraction of membrane
Formation of PAS
65

50.  Other factors contributing to glaucoma:
 Uveitis
 Pupillary block
 Underlying trauma
 Less virulent in course than epithelial ingrowth
66

51. FLAT ANTERIOR CHAMBER
After penetrating trauma or surgery
Formation of PAS
SACG without pupillary block
 Development of synechiae
 Duration of flat AC
 Degree of inflammation
 SACG common - AC remain flat for 5 days or more after
cataract extraction 67

52. IRIDOSCHISIS
 Patchy dissolution of iris in
which the ant stroma
separates from post stroma
and muscle layer
 rare condition
 elderly
 bilateral.
69

53.  Slit lamp biomicroscopy
 Shallow anterior chamber
 usually involves the inferior iris
 severity ranges from intrastromal
atrophy to disintegrated iris
fibrils
 Anterior stroma splits into
strands
 Project into AC
 Touch cornea
70

54.  Gonioscopy - narrow occludable angle – may be
associated with PAS.
 Treatment
 peripheral laser iridotomy.
 Subsequent treatment is aimed at limiting
glaucomatous damage.
71

55. 2. POSTERIOR ‘PUSHING MECHANISM
a. Ciliary block glaucoma (malignant glaucoma)
b. Intraocular tumors
c. Nanophthalmos
d. Suprachoroidal hemorrhage
e. Intravitreal air injection (e.g., retinal pneumopexy)
f. Ciliochoroidal effusions (e.g., panretinal
photocoagulation)
a. Inflammation (e.g., posterior scleritis)
b. Central retinal vein occlusion
g. Scleral buckling procedure
h. Retrolental fibroplasias 72

56. POSTERIOR PUSHING (OR ROTATIONAL)
MECHANISM
 Peripheral iris is displaced by lens, vitreous, or ciliary body often
accompanied by swelling and anterior rotation of the ciliary body
1. Swelling of ciliary body
Rotates forward about its attachment at scleral spur
Loosens the zonules
Diminishes diameter of ciliary ring
Displaces the root of iris
Which further acts to close angle.
73

57. MECHANISMS:
2. swelling of anterior uveal tract (inflammation or vascular
congestion)
Narrowing of ciliary ring
Reduced tension on lens zonules
Allows lens to come forward
Displaces peripheral iris
74

58. 3. Swelling of ciliary body is often accompanied by
accumulation of suprachoroidal and supraciliary fluid
further rotates ciliary body and iris root into angle
75

59. CILIARY BLOCK GLAUCOMA
 Syn:
 Aqueous misdirection
 Malignant glaucoma
 Hyaloid block glaucoma
 Posterior aqueous entrapment
 Described by von graefe 1869
 Definition: A shallow or flat AC with an inappropriately high IOP
despite a patent iridectomy
 Affects primarily patients who have narrow anterior chamber
angles 76

60.  Precipitating factors:
 As a complication of a filtering procedure in eyes
with pre-existing ACG or shallow AC
 Laser iridotomy
 Miotic usage
 Infectious endophthalmitis
77

61. PATHOGENESIS…
 Posterior misdirection of aqueous flow by a relatively
impermeable hyaloid membrane into or behind vitreous
body Increase in vitreous volume Shallower
AC Increase in IOP
Provocating factors:
 Small, crowded anterior segment
 Angle closure
 Swelling and inflammation of ciliary processes
 Anterior rotation of ciliary body
 Movement of lens-iris diaphragm forward 79

62. OCULAR MANIFESTATIONS
 red, painful eye: commonly after surgery for AACG
 Timing:
 Immediate- during surgery
 Months to years later
 Often corresponds to cessation by cycloplegic therapy or
initiation due to miotic drops
Slit-lamp examination
 Shallow or flat anterior chamber(central and peripheral)
 Asymmetry of AC with respect to fellow eye
 No iris bombé 80

63. Aqueous misdirection: flat anterior chamber despite a patent iridectomy. 81

64. DIAGNOSIS
 Clinical suspicion after ruling out
 Pupillary block
 Suprachoroidal hemorrhage
 Serous choroidal effusions
 Or other causes of a flat anterior chamber
 High-resolution ultrasound biomicroscopy:
 Anterior rotation of ciliary body against peripheral iris
 Forward displacement of posterior chamber intraocular
lens
 Shallow central AC 83

65. TREATMENT
 1st line: medical (cycloplegics and mydriatics)
 Atropine 1% and phenylephrine 2.5% QID : move lens-iris
diaphragm back and relax ciliary muscle
 Decrease aqueous production by:
 Topical β-blockers
 Oral or topical CAI
 α-agonists
 Shrink the vitreous volume. :
 Isosorbide 1.5 mg/kg orally
 Mannitol 2 g/kg intravenously over a 45-minute period
85

66.  No oral foods or liquids given 2 hours before and after
administration of a hyperosmotic agent
 Thus, avoid reduction in osmotic effect
 Atropine for prolonged period
 Very slow taper to avoid high risk of recurrence
 Miotic agents (contraindicated - may cause or contribute
to aqueous misdirection)
86

67. 2nd line of treatment: laser therapy:
 Neodymium:yttrium-aluminum-garnet (Nd:YAG)
 To create a large PI and anterior hyaloid rupture
 To release trapped aqueous from vitreous
 Re-establish normal aqueous flow
 Peripheral placement :
 Enable anterior migration aqueous
 Maximize likelihood of resolution of malignant
glaucoma.
87

68.  Pars plana vitrectomy
 Failed medical or laser therapy
 Phakic eyes for which laser treatment is not a good
option:
 Narrow angle in fellow eye - laser peripheral
iridectomy performed before any other surgical
procedures.
88

69. INTRAOCULAR TUMORS
 Ocular malignant melanoma
Mechanisms:
 Direct extension of tumor into TM
 Seeding of tumor cells into outflow channels
 Obstruction of meshwork by pigment or pigment-
laden macrophages
 Neovascularization
 PAS
 Iridocyclitis
 Hyphema
89

70. 
Iris melanoma.
Invading angle
Melanomas of choroid and ciliary
body:
•Displace lens–iris diaphragm
•Angle-closure glaucoma without
pupillary block
90

71. Leiomyoma pushing the peripheral iris
forward and closing off chamber angle.
Adenomas and leiomyomas:
Pushes iris forward and cause
angle-closure glaucoma.
91

72.  Retinoblastoma: frequently associated with glaucoma
 Mechanisms
 Neovascularization
 Angle seeding
 Iridocyclitis
 Hyphema
 By rapidly developing as posterior mass thus
displacing lens–iris diaphragm
 the mechanism in 27% of cases with elevated IOP.
92

73. NANOPHTHALMOS
 Normal shaped but small sized eye
 sporadic or inherited in an AD/AR pattern
 B/L
 M =F
 Prevalence: 0.06% and 0.1%
93

74. Features:
 Short AP length (20 mm)
 Small corneal diameter
 Lens: normal (even somewhat large, in size)
 Volume of lens: volume of eye =10–25% (normal=3–
4%)
 AC (central / peripheral): shallow
 Iris: anteriorly displaced
 Sclera: thick
 High hyperopia
94

75. OCULAR DIMENSIONS OF NANOPHTHALMIC
EYES
95

76.  Develop ACG :4th – 6th decades of life
 Can progress to total synechial closure
Angle closure precipitated by:
 Development of a choroidal effusion
 Rotates ciliary body anteriorly
 Displaces peripheral iris
 Loosens zonules
 Allows lens to move forward 96

77. SUPRACHOROIDAL HEMORRHAGE
 non-expulsive suprachoroidal hemorrhage
 rapidly developing posterior mass
 produce angle-closure glaucoma without pupillary block.
 most often seen after filtering operations in aphakic eyes
97

78. POSTERIOR SEGMENT INFLAMMATORY
DISEASE
 Posterior scleritis - increased IOP in 12–46%
 Mechanisms
 increased viscosity of the aqueous humor
 inflammation of the outflow channels
 obstruction of the trabecular meshwork by inflammatory cells
and debris
 PAS
 Neovascularization
 Elevated episcleral venous pressure
 also be associated with choroidal effusion
 secondary angle-closure glaucoma without pupillary block
 swelling and anterior rotation of the ciliary body 98

79. CLINICAL FEATURES
 shallow anterior chamber both centrally and peripherally,
 partial to total angle closure
 sectorial or circumferential choroidal effusion
 IOP - normal, high, or even low depending on the rate of
aqueous hum
Treatment
 Medical management
- systemic non-steroidal anti-inflammatory agents
- topical cycloplegic agents
- topical and systemic corticosteroids
- control IOP
99

80. CENTRAL RETINAL VEIN OCCLUSION
 Vein occlusion interferes with the venous
drainage of the uveal tract
 swelling and anterior rotation of the ciliary
body.
 transudation of fluid into the choroid, retina,
and vitreous.
 Medical treatment
 Laser gonioplasty
 Pupillary block - laser iridectomy
 If ischemia - retinal ablation after the anterior
chamber deepens
100

81. SCLERAL BUCKLING PROCEDURE
 ocular pain, nausea, vomiting, and
chemosis.
 Examination
 shallow anterior chamber both
centrally and peripherally
 corneal edema
 total angle closure
 Intraocular pressure - 25–50 mmHg
 serous or bloody choroidal detachment
101

82. MECHANISM
 displaces the lens, iris and ciliary body
 encircling band - temporary interference with the venous
drainage of the uveal tract
 swelling and anterior rotation of the ciliary body and
accumulation of supraciliary and suprachoroidal fluid.
 buckle may directly compress one or more vortex veins,
leading to vascular congestion and angle-closure
glaucoma..
102

83. PANRETINAL PHOTOCOAGULATION
 often followed by a shallow anterior
chamber and angle
 Asymptomatic
 Examination
 corneal epithelial edema
 shallow anterior chamber both
centrally and peripherally
 myopic shift in refraction
 choroidal detachment
 IOP in the range of 20–50 mmHg
 partial to total angle closure.
103

84.  Anterior chamber- deepens spontaneously over a few
days to a few weeks
 Mechanism
 interference with the venous drainage of the uveal tract
 leading to choroidal detachment
 swelling and anterior rotation of the ciliary body.
 Medical therapy
104

85. SECONDARY ANGLE CLOSURE WITH
PUPILLARY BLOCK
Lens-induced angle closure
105

86. PHACOMORPHIC GLAUCOMA
 abnormal lens either
compromises the lens–iris
channel (pupillary block) or
mechanically pushes the
peripheral iris forward into the
angle structures.
 intumescent cataracts - crowd
the anterior chamber
 swelling, dislocation or
subluxation –laser iridotomy
106

87. Intumescent and swollen lens
 Increased pupillary block - develop slowly with an age-
related cataract or rapidly with a traumatic, swollen
cataract.
 Unilateral and resembles PACG
 Definitive treatment - cataract extraction.
 Iridotomy
107

88. ECTOPIA LENTIS :
Displacement of lens from its normal anatomical position
Forward displacement
Iris bombe
Shallowing of the anterior chamber angle
Pupillary block
Secondary angle closure. 109

89. CLINICAL PRESENTATION:
 Acute:
 Pain
 Conjunctival hyperemia
 Loss of vision
 Chronic ACG:
 PAS formation secondary to repeated attacks
110

90. TREATMENT
 Long term treatment with miotic agents to prevent
forward movement of lens.
 Treatment of choice to relieve pupillary block :
 Two laser iridotomies (180° apart) pupillary block
 Definitive t/m: lensectomy
 Lens extraction- Indication:
 to restore vision
 to reduce risk of recurrence of pupillary block 111

91. APHAKIC OR PSEUDOPHAKIC ANGLE-
CLOSURE GLAUCOMA
 Extensive adhesions of the
iris to the vitreous face -
produce pupillary block and
secondary angle-closure
glaucoma
 Iridectomy is not patent,
occluded, or omitted
 Adherence of the iris to an
intraocular lens (IOL)
112

92.  With anterior chamber lenses the
optic may form a ball valve type seal
over the pupil while the haptic covers
the iridectomy.
 Iridectomies spaced far enough apart
to prevent the haptics from occluding
the openings
113

93. MICROSPHEROPHAKIA
 Congenital
 Spherical or globular lens
 Often familial
 May occur as an isolated condition
 Or as part of either Weill-Marchesani or Marfan syndrome.
 Can cause ectopia lentis and subsequent pupillary block and
ACG
lens (arrow) is trapped anteriorly by pupil,
resulting in iris bombe and dramatic shallowing of AC
114

94. TREATMENT
 Cycloplegia
 tighten zonule, flatten lens, and pull it posteriorly,
breaking pupillary block
 Miotics may worses the condition by
 Rotating ciliary body forward
 loosening the zonule
 Allowing lens to become more globular
115

95. BIBLIOGRAPHY
# Becker-Shaffer's Diagnosis and Therapy of the Glaucomas;
8th Ed.
# American Academy of Ophthalmology BCSC. Section 10;
2015-2016
# Shields Textbook of Glaucoma; 6th Ed.
# Yanoff and Duker Ophthalmology 5th Ed
116

96. Thank you
117