Trabeculectomy is the gold standard glaucoma surgery for lowering intraocular pressure. It involves creating a fistula between the anterior chamber and subconjunctival space to bypass the trabecular meshwork. Complications include hypotony from overfiltration, flat or shallow anterior chambers, elevated pressure, hemorrhage, and infection. Careful surgical technique and postoperative management can help prevent or address complications and optimize outcomes.

1. Trabeculectomy,
Trabeculotomy,
Goniotomy and their
complications
DR. NAMRATA GUPTA

2. Incisional Surgery
Frequently used for chronic forms of glaucoma in adults –
Filtering procedure
External filtration:
• Full thickness(Scheie) procedures:Thermal sclerostomy,
sclerectomy, Elliott’s trephination
• Guarded procedures:Trabeculectomy
Internal filtration:
• Cyclodialysis
Trabecular meshwork disruption:
• Trabeculotomy ab externo
• Goniotomy

3. Trabeculectomy

4. Introduction
• Trabeculectomy, a guarded filteration procedure remains
the ‘gold standard’ for long lasting intraocular pressure
reduction in uncontrolled glaucoma
• Popularized by Cairns (1968)

5. Mechanism of action
• Creation of a fistula at the limbus which allows a direct
communication between anterior chamber and
subconjunctival space bypassing the trabecular
meshwork, schlemm canal and collecting channels

6. Theories of mechanism
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2

7. Pre-operative evaluation

8. Indications
• Intraocular pressure too high to prevent future glaucoma
damage and functional visual loss
• Documented progression of glaucoma damage at current
level of intraocular pressure with treatment
• Presumed rapid rate of progression of glaucoma damage
without intervention
• Poor compliance with medical therapy : cost ,
inconvenience, understanding of disease
• Intolerance to medical therapy due to side effects

9. Assessment of filtration risk factors
• Thorough slit lamp evaluation, gonioscopy, record review of
past surgery
• Best site for filtration determined: PAS, IOL and haptic
orientation, aberrant vessels, wound dehiscence, limbal
scarring, vitreous prolapse
• Risk factors for filtration failure: African race, uveitis,
aphakia, neovascular glaucoma, prior failed filtration,
prolonged anti-glaucoma medication
• Ocular surface disease: ocular rosacea, blepheritis

10. SurgicalTechnique
Perioperative preparations:
• Intravenous sedation : pediatric, adults unable to co-
operate
• Local anesthesia: Retro-bulbar injection, peribulbar
injection, subtenon, subconjunctival or topical anesthesia
• Positioning to maximize exposure to superior globe:
protection by lid, no diplopia after PI

11. Traction sutures
• Superior rectus traction (or bridle) suture
• Complications: subconjunctival hemorrhage, conjunctival
defects, scleral perforation postoperative ptosis

12. Traction sutures
• Clear Corneal traction sutures:A 7-0 polyglactin (vicryl)
suture is passed through approx. ¾ th thickness of superior
peripheral cornea(4-5 mm width) 1mm form limbus
• May distort the cornea and anterior chamber during surgery

13. Conjunctival flap
General principles:
• Gentle handling- buttonholing (antifibrotics)
• Removal of portion ofTenon capsule : source of fibroblast
(controversial)

14. Conjunctival flap
Two types of conjunctival
flap:
• Limbal based
conjunctiva flap (LBCF)
– incision deep in fornix
with base at limbus
• Fornix based
conjunctival flap (FBCF)
– incision at limbus with
base at fornix

15. Limbal based versus fornix based flap

16. Anti-metabolite decision
• Adjunctive antimetabolites inhibit the natural healing
response that may preclude successful filtration surgery
• Stratified according to patient risk factors

17. 5-Fluorouracil
• Pyrimidine analogue antimetabolite
• Inhibition of thymidylate synthesis, blocks DNA synthesis
• Inhibit fibroblastic proliferation
• Concentration: Cellulose sponge soaked in 50mg/ml for 5
mins

18. Mitomycin C
• More potent than 5-FU
• Antineoplastic antibiotic isolated from Streptomyces
caespitosus
• Selectively inhibits DNA replication, mitosis and protein
synthesis-inhibits proliferation of fibroblast, suppresses
vascular ingrowth
• Concentration: 0.2-0.5 mg/ml for 1-5 mins depending on
magnitude of risk factors

19. Delivering the anti-fibrotic agent
• Cellulose sponge ̴5 × 3 mm soaked in antimetabolite is
placed under dissected tenon’s capsule for 5 mins before
paracentesis of AC followed by thorough irrigation with
BSS

20. Ring of steel
• Cover largest area possible for more diffuse noncystic bleb
and prevent posterior limiting scar (‘ring of steel’)

21. Moorfields Eye Hospital (More Flow) intra-
operative Single Dose Anti- Scarring
Regimen 2006
Low Risk Patients (Nothing or intra-operative 5-FU
50mg/ml)
• No risk factors
• Topical medications (beta-blockers/pilocarpine)
• Afro-Caribean
• Youth <40 with no other risk factors

22. Intermediate risk patients (intraoperative 5-FU 50mg/ml
or MMC 0.2 mg/ml)
• Topical medications (adrenaline)
• Previous cataract surgery without conjunctival incision
• Combined glaucoma filtration surgery/cataract
extraction
• Previous conjunctival surgery eg. Squint surgery/
detachment surgery/ trabeculotomy
More flow contd.

23. High risk patients (Intra operative MMC 0.5 mg/ml)
• Neovascular glaucoma
• Chronic persistent Uveitis
• Previous failed trabeculectomy/tubes
• Chronic conjunctival inflammation
• Secondary glaucomas: inflammatory, post-traumatic
angle recession, iridocorneal endothelial syndrome
• Aphakic glaucoma
More flow contd.

24. Complication of antimetabolites
• Corneal epithelial defects
• Post-operative wound leaks
• Cystic thin walled bleb: Chronic hypotony, late-onset bleb
leak, endophthalmitis

25. Scleral flap dissection
• Provide resistance to aqueous outflow and prevent hypotony
• Act as a safety valve to minimize IOP fluctuations
• Technique:
• Rectangular(3.5 x 4.5 mm) or triangular partial thickness
( ̴50%)
• Lamellar dissection anteriorly just into clear cornea

26. Difficulties
• Thin scleral flaps– reduced flap resistence and hypotony
• Flap dehiscence, full thinkness button holes, cheese wiring
• Important in eyes with low scleral rigidity: buphthalmos,
myopia, antifibrotic use

27. Paracentesis
An oblique paracentesis in inferior cornea allows fine control
of the AC:
• IOP titration after tying the scleral flap sutures
• Reformation (or decompression ) ofAC intra or post
operatively- BSS or viscoelastics
• Infusion for continuous IOP maintainence in high risk
• Control and washout of AC hemorrhage

28. Sclerostomy
• Anterior corneoscleral entry into AC- reduces risk of iris
incarceration and bleeding from iris root and ciliary body
1. Punch sclerostomy- Khaw/ Kelly descement membrane
punch
2. Manual block removal
clean 0.75mm round hole without tissue tags

29. Peripheral iridectomy
• Routine part of all standard filtering procedures
• Performed from sclerostomy site with extent beyond
sclerostomy margins to avoid obstruction of sclerostomy by
peripheral iris
Complications:
• Hyphaema, inflammations, iridodialysis

30. Closure of the wound
• Approximation of scleral flap with nylon 10-0 that
achieves mild to moderate resistance to aqueous flow
maintaining AC depth is optimal
• Adequate flow resistance can be tested by injecting BSS
into AC via paracentesis

32. Scleral flap sutures- Fixed,
Releasable , Adjustable

33. Fixed sutures and laser suture lysis
• Laser suture lysis introduced by Lieberman (1983) using
argon laser
• Facilitated by compressing overlying conjunctiva to visualize
scleral suture or high magnification suture lysis contact lens
(Hoskins or Blumenthal lens)
• Argon laser: 50µm, 0.1 sec duration, 250-1000 mW power
• Within first 3 weeks: enhance filtration before scarring occurs
• Delayed (upto 8 weeks) if intraoperative antimetabolite used

34. Laser suture lysis

35. Releasable sutures
• Preferred: Scleral flap sutures obscured by subconjunctival
hemorrhage, thickened tenon’s capsule or fibrosis
• First originated from Shaffer et al (1971)
• Simple, low-cost and efficacious

37. Adjustable sutures
• Allows trans-conjunctival adjustment of tension post-
operatively for gradual titration of IOP using specially
designed forcep with blunt tip
• Khaw adjustable suture forcep

38. Adjustable suture forcep

39. Post-operative management
Medications:
• Topical steroids: early restoration of blood aqueous barrier
and suppression of wound healing
• Prednisolone acetate (1%) 2 hourly for 2 weeks and tapered
over 8 weeks
• Topical antibiotics: 4 weeks post operatively
• Topical mydriatic/cycloplegic agent : Atropine 1% prevents AC
shallowing and risk of malignant glaucoma
• Oral or IV steroids: not routinely used , in severe uveitic
glaucoma

40. Scleral flap suture manipulation
• Removal of one or more releasable scleral flap sutures
• Laser suture lysis
• Adjustable suture loosening
Incorrect timing may result in hypotony or permanent
subconjunctival fibrosis and GFS failure

41. Adjuvant subconjunctival 5-
Fluorouracil
• Inhibits fibrosis inTenon’s layer
• After first postoperative week for up to several months to
modulate wound healing (useful in presence of subtenon
lake)
• 5mg (0.1 ml of 50mg/ml) 5-FU deep in superior fornix of
90° from the bleb

42. Adjuvant subconjunctival 5-
Fluorouracil
• Signs of impending bleb failure
• Increased bleb vascularity
• Thickening of conjunctiva and tenon’s capsule
• Reduction in bleb size and height
• Reduction of conjunctival microcyst
• Progressive elevation of IOP

43. Bleb Needling Revision
• Failure of previous methods
• Puncturing and loosening the scar tissue of filtration bleb
to increase sub-tenon’s aqueous lake
Two types of BNR:
1. Sub-Tenon’s Needling
2. Subscleral flap Needling

44. Subtenon’s needling

45. Subscleral Flap Needling
• Early post operative subscleral flap needling if sub tenon’s
Needling fails

46. Complications
Intra-operative complications
1. Conjunctival tear
2. Hemorrhage
3. Scleral flap damage
4. Supra-choroidal Hemorrhage
5. Decompression Retinopathy

47. Intra operative Complications
• Tearing or buttonholing of cinjunctival flap:
Prevention :
• Minimal handling
• Topical adrenaline to reduce vascularity and bleeding
• Stromal hydration- BSS injected under cinunctiva/tenon to make
them thicker
• Blunt dissection

48. Tearing or buttonholing of conjunctival flap
Management:
• Small holes-Tissue adhesives, light bipolar cautery
Figure of 8 or mattress suture
• Large holes- Purse string vicryl suture

49. Hemorrhage:
Should be minimized as blood is potent stimulus for fibrosis
Risk factors:
• Long term anti-glaucoma medication
• Aspirin, anti-coagulants
Management:
• Wet field diathermy
• Gentle sustained pressure over fistula
• Large air bubble or viscoelastic in AC

50. Scleral flap damage: tearing and buttonholing
• Avoid thin flap and excessive manipulation
Management:
• Minor damage- repair
• Severe damage- autologous or donor sclera patch

51. Suprachoroidal hemorrhage: Sudden reduction in IOP with
rupture of a large choroidal vessel
• Risk factors:
• High pre-operative pressure
• Generalized atherosclerosis
• Elevated intraoperative pulse
• Young patient
• Large eyes, nanophthalmos
• Sturge –weber syndrome
• Management:
• All wounds closed rapidly
• Peripheral SCH: conservative
• Extensive SCH- rainage

52. Decompression retinopathy
• Retinal hemorrhage following rapid IOP reduction
Vitreous loss
• Inadvertent damage to lens/zonule complex during PI
• Prevention:
• Anterior sclerostomy
• Avoid basal PI’s
• Tube surgery in iridolenticluar instability

53. Post operative complications
Early post-operative complications:
1) Hypotony and shallow anterior chamber
2) Hypotony and deep anterior chamber
3) Elevated intraocular pressure and flat anterior chamber
4) Elevated intraocular pressure and deep anterior chamber

54. Spaeth classification of post operative
shallow anterior chamber:
• Grade 1: peripheral iris- cornea apposition
but preserved AC in front of pupillary
space
• Grade 2: Greater apposition between mid
iris and cornea but space between lens(or
vitreous) and cornea in pupillary space is
retained
• Grade 3: Flat AC with complete contact of
iris and pupillary space with posterior
surface of cornea

55. Hypotony with flat anterior chamber:
A.Negative seidel test with grade I or II flat AC with
hypotony with a formed bleb- Scleral flap leak
Management:
• Conservative :Topical steroids and long acting cycloplegic
• Restricted activity and avoidValsalva
• Pressure patch of filtration site

56. Pressure patch technique

57. Hypotony with flat anterior chamber:
B. Positive Seidel test with grade I flat anterior chamber and
low intraocular pressure- small leaks around sutures
• Increased frequency of topical antibiotics
• Pressure patching
• Therapeutic contact lens- Fibrin tissue glue or cyanoacrylate glue
• Simmon shell

58. C. Positive seidel’s test with low bleb height with grade II
or III flat AC with hypotony: Conjunctival button hole
Management:
• Conjunctival tear:
Healthy conjunctiva: Purse string suture
Fragile conjunctiva: Pressure patching, 20-22 mm BCL,Tenon
capsule sutured a tear site
• AC reformation: Air, BSS, viscoelastics

59. Hypotony with flat anterior chamber:
B. Excessive filtration:
• Loose scleral flap closure or large filtering bleb (anti-fibrotic)
• Large soft contact lens
• Symblepheron ring
• Simmons shell
• Surgical:Viscoelastics, BSS, 15% perfluoropropane(C3F8),
40% sulfur hexa fluoride(SF6)
Symblepheron ring

60. Hypotony with flat anterior chamber:
C. Serous choroidal detachment
Mechanism:
• Pressure differential in hyotonic eyes causes fluid with
small and medium sized proteins to diffuse from
choroidal capillaries to extravascular space
• Prolongs hypotony by reduced aqueous production and
increased uveoscleral outflow

61. Management:
• Resolve spontaneously after IOP rises above 7-9 mmHg:
Atropine and oral and topical steroids
• Surgery: Persistence of grade 3 flat AC more than 1 week
with corneal endothelial compromise or persistence of
‘kissing choroidals’ or suspected SCH:
• One or more sclerotomies 4mmbehind the limbus over pars
plana in inferior quadrants and deepening AC with BSS

62. Hypotony with deep anterior chamber:
• A lower-than-normal IOP in first 2 weeks with no
associated complication resolve spontaneously
• Persistent hypotony(<6mmg): Hypotony Maculopathy
• Fine macular striae radiating from fovea
• Extensive choroidal folds
• Tortuous retinal vessels
• Disc edema
• No evidence of vascular leak

63. • Risk factors:Young age, male gender, myopia, preoperative
CAI, antimetabolites, iridocyclitis, cyclodialysis, ciliochoroidal
detachment
• Management:
• Pressure patching
• Large BCL
• Autologous blood injected into bleb
• Surgical: Conjunctival compression sutures, resuturing of
scleral flap, patch graft with donor sclera
Return of good vision seen with reversal of over-filtration
within 6 months of onset

64. 3. Elevated IOP with flat anterior chamber
a) Aqueous misdirection syndrome(malignant glaucoma)
b) Delayed suprachoroidal hemorrhage
c) An incomplete iridectomy with pupillary block glaucoma-
Patentcy should be established immediately on diagnosis by
laser or, if necessary, incisional surgery

65. Aqueous misdirection(ciliary block
/malignant glaucoma)
• Misidrection of aqueous to circulate into vitreous
• Grade II or III shallow AC
• Higher than expected IOP in early post-operative
period
• Patent iridotomy
• Rarity of spontaneous resolution- ‘malignant’

66. Malignant glaucoma
Management:
• Atropine and topical steroids
• Aqueous suppressants: Brimonidine,Timolol, CAI’s, IV
mannitol
• Surgical intervention: waiting period of 5 days advised
• Nd-Yag laser- pupillary block, retrocapsular block or hyaloid
block
• Pars plana vitreous aspiration or Pars plana vitrectomy
• Cyclodiode photocoagulation (refractory cases)

67. Suprachoroidal hemorrhage
Risk factors:
• Aphakic
• Post-traumatic
• Vitrectomised eyes
• Large eyes- Pathological myopia/Congenital glaucoma
• Systemic anticoagulants
• Significant post-operative hypotony

68. Suprachoroidal hemorrhage
• Sudden severe pain with loss of vision during first 4-5 post-
operative days
• High IOP with nausea and vomiting
Management:
• Aqueous suppressants/ hyperosmotic agents
• Surgical drainage: Posterior sclerostomy over area of
elevated choroid after 7-10 days with simultaneous AC
infusion
Poor prognosis with concomitant RD or 360° SCH

69. 4. Elevated IOP with deep anterior chamber:
Indicates inadequate filtration
• Tight scleral flap
• Obstruction of fistula by iris, ciliary process, lens, blood or
vitreous
Management:
• Tight flap: Laser suture lysis
• Obstruction of fistula: Retraction of obstructing tissue with argon
laser of Nd-Yag disruption under gonioscopy
• Pressure on posterior lip: clot or vitreous at sclerostomy site
• Internal bleb revision: Cyclodialysis spatula inserted 90-180° away
through clear corneal incision into the fistula to elevate scleral flap

70. Failing bleb
Characteristics:
• Typically low-flat
• Heavily vascularized
• No microcysts
Management:
• Increased frequency of topical steroid ± subconjunctival steroid/5-
FU
• Intermittent digital pressure
• Laser suture lysis/ removal of adjustable suture
• Failure of above: Anti-glaucoma resumed and revision of surgery

71. Bleb manipulation techniques
Bleb massage
• Digital pressure through upper lid
as posterior as possible to scleral
flap under direct slit lamp
visualization
• Steady pressure with index finger
to inferior sclera through lower lid
for 15 seconds
Repeated several times over first few
weeks

72. Encapsulated filtering bleb
• In 3.6% - 28% within first 2 months after surgery
• Tenon capsule cysts: Highly elevated, smooth doomed
bleb with intervening avascular spaces and no microcysts
• Patent sclerostomy on gonioscopy
• Management:
• Resume anti-glaucoma medication until improvement
occurs
• Subconjunctival needling with 5mg of 5-FU subconjunctivally

73. Other early post-operative
complications
• Uveitis
• Hyphaema
• Dellen: Adjacent to large filtering bleb
• Loss of central vision:
“Snuff-out syndrome”- common in old age, hypotony,
macular splitting(visual field loss within 10° of fixation)

74. Late post operative complication
a) Late failure of filtration :
• Fibrosis of scleral flap
• Scarring of conjunctiva
• Poor response to drugs or digital pressure
• Management:
• Ab externo or ab interno incision of membranous tissue over
fistula
• Argon laser for pigmented membrane
• Nd-Yag laser for non pigmented membrane
• Incisional surgery

75. Late post operative complication
b) Leaking filtering bleb
• Thin walled large avascular blebs are at risk
• Use of adjunctive anti-metabolite
• Management:
• Cyanoacrylate glue, autologous fibrin, large BCL
• Bleb revision: New conjuntival flap or rotational conunctival
flap

76. c) Bleb related infections
• Blebitis and endophthalmitis are potentially blinding
emergencies
• Tends to occur months or years after surgery
• Prevention of late infection
• Avoid excessive antifibrotic treatment
• Avoid thin scleral flaps
• Bleb under upper lid

77. Blebitis
• White bleb with surrounding intense conjunctival injection
• Variable anterior chamber reaction
• Clear vitreous
• Risk factors:
• Early chronic intermittent bleb leak
• Myopia: thin scleral flap
• Intra-operative MMC
• Blepheritis
• Diabetes mellitus
• Chronic antibiotic use
Treatment:Topical antibiotics

78. Bleb-related Endopthalmitis
1. Early postoperative Endophthalmitis:
• Onset within first 3 months
• Staphylococcus epidermidis
2. Delayed- onset Endophthalmitis
• Onset after 3 months
• Streptococcus, staphylococcus, H. influenzae

79. Bleb-related Endopthalmitis
• Milky white appearance of bleb, fibrin or hypopyon in AC
and vitritis (distinguishes from blebitis)
• Management:
• Aqueous and vitreous aspirates
• High dose parenteral and periocular antibiotics
• Intravitreal antibiotics
• Poor visual prognosis

80. Other late post operative
complications
• Development and progression of cataracts
• Spontaneous hyphaema
• Hypotony and ciliochoroidal detachment: inflammation,
aqueous suppressants
• Rare: Upperlid retraction, sympathetic ophthalmia

81. Goniotomy andTrabeculotomy

82. Definition
Goniosurgery
• First introduced by Barkan (1938)
• Specific surgical techniques applied to the anterior segment of
the eye for the treatment of childhood glaucoma
• Principle:
Incision of the obstructing trabecular meshwork tissue allows
direct conduit between anterior chamber and schlemm’s canal

83. Goniotomy
Indications:
1. Primary congenital infantile open angle glaucoma(3- 12
months)
2. Other primary glaucomas
• Juvenile open angle glaucoma
• Axenfled Rieger syndrome, Lowe syndrome
• Neurofibromatosis, Sturge weber syndrome
3. Selected secondary glaucoma
• Open angle glaucoma after congenital cataract surgery
• Glaucoma with chronic anterior uveitis

84. • Goniotomy is advisable as soon as possible after diagnosis
as early as second or third day of life in glaucoma present at
birth
• It is recommended once or twice in children younger than 2-
3 years
• Shaffer reported that one to two goniotomies cured 94% of
cases between 1 and 24 months
• Advantages: Does not disturb conjunctiva, direct
visualization of trabecular meshwork

85. Goniotomy
Preoperative care:
• Preoperative glaucoma medications to reduce IOP and clear
cornea
• Beta-blockers (0.25%), Oral acetazolamide (10-15 mg/day) or
topical dorzolamide with apraclonidine 0.5%
• Pilocarpine 1-2% just before surgery to promote miosis
• Rule out congenital NLD block or URTI
• Isopropyl alcohol 7-% to remove corneal epithelium if edema
persists(intraoperatively)

86. • Procedure:
• Eye positioned with plane of iris tilted away from surgeon
at 45°
• Locking fixation forceps on vertical recti, if nasal or
temporal goniotomy is to be performed
• Operating microscope tilted towards the surgeon for
comfortable view of angle through goniolens

87. • Swan goniotomy knife
• Swan Jacob goniolens

89. Complications:
• Risk of general anesthesia in neonates and infants
• Hemorrhage: Incision into anterior ciliary body, sclera
• Cataract: lens injury
• Infection
• Epithelial ingrowth
• Failure: Incision anterior to schwalbe line

90. Post-operative care:
• Patient’s head turned towards side of puncture wound for
first hour that facilitates blood from goniotomy incision to
flow away
• Routine F/U: Infection, cornea, AC, IOP
• EUA after 4-6 weeks
• Reoperation may be performed after 3 weeks
• Trabeculotomy: If two goniotomies fail

91. Trabeculotomy
• Performed by cannulating the schlemm canal from an
external approach with subsequent centripetal rupture
through the trabecular meshwork into the anterior chamber
Indications:
• Same as that of goniotomy in presence of corneal edema or
opacification
• After failure of two previous goniotomies
• Combined with trabeculectomy (failure to cannulate
schlemm canal)

92. • Harms trabeculotome
• McPherson probe

93. Procedure
• Thick scleral flap created(deeper than trabeculectomy)
• Radial incision made in bed of flap at sclero-corneal
junction and deepened until schlemm canal identified
anterior to scleral spur(near posterior limbal gray zone)
• A 6-0 blunt tip prolene is threaded on either side of radial
incision to confirm patency
• Internal arm of trabeculotome passed gently into canal and
rotated into AC through interveningTM

94. Purse- string 360°Trabeculotomy
• After unroofing and identifying schlemm’s canal, a 6-0
prolene suture is threaded 360°around
• After reappearing form the opposite direction at initial
surgical site, suture is drawn like a purse string rupturing the
entire canal in centripetal fashion

96. Complications
• Intra or Post operative hyphaema
• Descement’s detachment
• Iridodialysis
• Iris prolapse

97. Summary
• Trabeculectomy is a surgical procedure featuring a partial
thickness scleral flap that creates fistula between anterior
chamber and subconjunctival space for filtration of aqueous
fluid and formation of bleb ± antimetabolites
• Gold standard for glaucoma surgery
• Associated features- Hypotony, choroidal detachment, bleb
leak and bleb associated endophthalmitis
• Goniotomy and trabeculotomy are specific surgical
techniques applied to anterior segment for treatment of
childhood glaucoma

98. Bibliography
• R.Rand Allingham. ShieldsText Book of Glaucoma, 6th
edition , 2011
• Robert L Stamper, Marc F Lieberman, MichaelV Drake.
Becker- Shaffer’s Diagnosis &Therapy of the Glaucomas,
8th edition, 2010.
• Daniel M Albert, JoanW Miller, DimitriT Azar. Albert &
Jakobiec’s Principle and Practice of Ophthalmology, 3rd
edition, 2008.
• American Academy of Ophthalmology.The Glaucoma,
Section -7, 2011-12.
• MyronYanoff and Jay S. Duker – Ophthalmology, 3rd
edition, 2009.

99. THANKYOU