Everything one needs to know about complications of trabeculectomy and their management

1. COMPLICATIONS OF TRABECULECTOMY
Sumeet Agrawal
PG 3
UCMS and GTB Hospital,
Delhi

2. INTRAOPERATIVE POSTOPERATIVE
EARLY LATE
Buttonhole of conjunctiva
HYPOTONY
-Flat anterior chamber
-Deep anterior chamber
Thinning and leaking bleb
Scleral flap tear
ELEVATED IOP
-Flat anterior chamber
-Deep Anterior chamber
Large overhanging bleb
Lens injury ‘Snuff out’ phenomenon Bleb related infections
Hemorrhage Cataract
Choroidal effusion
Descemet’s stripping

3. Early
postoperative
complications
Hypotony
Flat Anterior
Chamber
Deep Anterior
Chamber
Elevated
IOP
Flat Anterior
Chamber
Deep
Anterior
Chamber
• Aqueous misdirection
• Pupillary block
• Delayed Suprachoroidal
hemorrhage
Failing bleb
• Internal block
• Encapsulation
• Leaking bleb
• Overfiltration
• Choroidal effusion
• Overfiltration

4. MEASURING IOP
• Digital palpation
• Avoid filtering site

5. Early
postoperative
complications
Hypotony
Flat Anterior
Chamber
Deep Anterior
Chamber
Elevated
IOP
Flat Anterior
Chamber
Deep
Anterior
Chamber
• Aqueous misdirection
• Pupillary block
• Delayed Suprachoroidal
hemorrhage
Failing bleb
• Internal block
• Encapsulation
• Leaking bleb
• Overfiltration
• Choroidal effusion
• Overfiltration

6. HYPOTONY with FLAT AC
• LEAKS
– Siedel’s test
• From the wound
• From a button hole
• Iridocorneal touch
– Spontaneous deepening in 7-14 days
• Corneo-lenticular touch
– Look for corneal edema
– Aggressive intervention

7. MANAGEMENT
• Conjunctival leak :
– Reduce steroids
– Pressure patch
– Large diameter
contact lens
– Fibrin glue
– Surgical repair
• Overfiltration:
– Reduce steroids
– Pressure patch
– Mydriatic-cycloplegics
– Large diameter contact
lens
– Surgical repair
Reformation of AC :
• Viscoelastic
• Air
• SF6
• C3F8

9. CHOROIDAL EFFUSION:
• Easily visible ora
• Usually resolves
spontaneously
• Oral steroids
• Drain if :
– Corneo-lenticular touch with decompensation
– Kissing choroids
– Prolonged hypotony (no signs of improvement
within 4 weeks)

10. HYPOTONY with DEEP AC
• Benign course
• Rule out treatable causes
• Persistent hypotony  Hypotony maculopathy
(reversible till 6 months)
• Autologous blood injection in
the bleb
• Bleb compression sutures
• Surgical (resuturing, scleral patch
graft)
• Reforming the bleb

11. Early
postoperative
complications
Hypotony
Flat Anterior
Chamber
Deep Anterior
Chamber
Elevated
IOP
Flat Anterior
Chamber
Deep
Anterior
Chamber
• Aqueous misdirection
• Pupillary block
• Delayed Suprachoroidal
hemorrhage
Failing bleb
• Internal block
• Encapsulation
• Leaking bleb
• Overfiltration
• Choroidal effusion
• Overfiltration

12. ELEVATED IOP with SHALLOW AC
• Compare periphery and axial AC
– Aqueous misdirection (periphery and axial)
– Pupillary block (only peripheral)
– Delayed Suprachoroidal Hemorrhage (peripheral
and axial)

14. MANAGEMENT
(A good sized patent surgical PI rules out Pupillary block)
AQUEOUS MISDIRECTION
• Discontinue miotics
• Strong cycloplegics
• Topical steroids
• Aqueous suppressants
(50 % resolve in 5 days*)
• Disrupt the vitreous face
(laser, PPV, needle aspiration)
*Yaqub M, et al: Malignant glaucoma. In: El Sayyad F, et al, editors: The refractory glaucomas, New York, Igaku-Shoin, 1995.
PUPILLARY BLOCK
• Peripheral iridectomy/otomy
• Avoid cycloplegics/mydriatics
• Topical steroids
• Aqueous suppressants
• Miotics

15. Delayed
Suprachoroidal
Hemorrhage
• Associated symptoms:
– Severe pain
– Nausea
– Marked sudden
diminution of vision
– Manage IOP
– Wait for clot lysis (14
days)
– Drain

16. ELEVATED IOP WITH DEEP AC
• INADEQUATE FILTRATION

17. Elevated IOP with a deep anterior chamber
Typical failing bleb
• Low to flat
• Heavily vascularized
• No microcysts
• 6.9 to 36 %
• Tight sutures
• Internal block
• Early, aggressive
intervention required
Tenon’s cyst
• Highly elevated
• Smooth-domed
• Large vessels but intervening
avascular spaces, no microcysts
• Patent sclerostomy
• 3.6% to 28%
• Within the first 2 months
• Most resolve on conservative
management

18. Most important step : recognising its presence
• Preceded by a gradual increase in IOP
• Change in the bleb's appearance
– Less diffuse
– Avascular (large vessels but
intervening avascular spaces)
– Opalescent
– Flat / very elevated, smooth-domed
– Surrounding fibrotic vascular ring
– Loss of microcysts (fluorescein)
• Pressure does not decreases
after massaging

19. SEEK OUT THE CAUSE
• BLOCK OF INTERNAL OSTIUM
• EXTERNAL BLOCK (most common)

20. • INTERNAL BLOCK
– Iris
– Ciliary body
– Vitreous
– Blood clot
– Fibrin
• Gonioscopic evaluation
• EXTERNAL BLOCK
– Tenon’s cyst
– Episcleral scarring
• Careful slit lamp evaluation

21. MANAGEMENT

22. RAISED IOP
• Digital ocular pressure
– steady pressure over the inferior sclera, through
the eyelids for 10 to 15 seconds
– intermittent
– taught to the patient
• Medical
– Topical (avoid PG anlogues, Brimonidine)
– Systemic

23. • Frequent anti-inflammatory therapy
• Laser suture lysis
– first 3 wks without antimetabolites; 8 wks with
antimetabolites
– argon or green light laser
– Nd YAG laser. Ruptures conjunctival and episcleral
blood vessels
– 400 mW, 0.01 seconds and 50 μm
– one suture at a time, if no effect within 1 hour, second
suture lysis or removal may be considered
RESTORING BLEB FUNCTION

24. • Without magnification
– Edge of a four-mirror gonioprism
– Hoskins laser suture lens
• High-magnification suture lysis contact lenses
– Mandlekorn lens
– Blumenthal lens
– Ritch lens

25. HOSKINS LENS

26. • Releasable sutures
• Topical mitomycin C (0.02% QID for 2 weeks)
• Bleb revision
BLOCKED INTERNAL OSTIUM
• Intracameral tissue plasminogen activator (blocked
internal ostium; blood or fibrin clot )
– 6 to 12.5 µg
– Frozen (TPA) - 25 g/ 0.1ml is diluted with 0.9 % NaCl
• Low-energy argon laser therapy / Nd:YAG laser
disruption (retract the tissue)
– Iris
– Vitreous
• Internal bleb revision

29. EXTERNAL BLEB REVISION
• Tenon’s cyst / episcleral scarring unresponsive to
conservative management
• First described by Ferrer1 in 1941
– conjunctival dialysis
– incising the scar tissue
– conjunctiva from the sclera with a spatula
• Pederson and Smith2
– needling encapsulated blebs
– 69% success
1.Ferrer H. Conjunctival dialysis in the treatment of glaucoma recurrent after sclerectomy. Am J Ophthalmol. 1941;24:788-
790.
2.Pederson JE, Smith SG. Surgical management of encapsulated filtering blebs. Ophthalmology. 1985;92:955-958.

30. • Ewing and Stamper3
– 5-fluorouracil (5-FU) in bleb needle revisions
– Postop subconjunctival injections
– 91.6% success rate
– 63.6% : adjunctive medications
• Shin et al4
– single injections of 5-FU during needling
– 80% success rate
– 79% : adjunctive medications
3.Ewing RH, Stamper RL. Needle revision with and without 5-FU for the treatment of failed
filtering blebs.Am J Ophthalmol. 1990;110:254-259.
4. Shin DH, Juzych MS, Khatana AK, et al. Needling revision of failed filtering blebs with
adjunctive 5-fluorouracil. Ophthalmic Surg. 1993;24:242-248.

31. • Mardelli et al.5 in 1996,
– Slit-lamp procedure
– Mitomycin C (MMC) injections
– 92% success rate
5.Mardelli PG, Lederer CM Jr, Murray PL, et al. Slit-lamp needle revision of failed filtering
blebs using mitomycin C. Ophthalmology. 1996;103:1946-1955.

32. • Risk factors for failed needling
– Pre procedure IOP > 30 mm Hg
– Trabeculectomy without MMC
– Immediate post procedure IOP >10 mm Hg
– After 4 months of trabeculectomy6
6.Gutierrez-Ortiz C, Cabarga C, Teus MA. Prospective evaluation of preoperative
factors associated with successful mitomycin C needling of failed filtration blebs. J
Glaucoma. 2006;15:98-102.

33. TECHNIQUE FOR NEEDLING
• Goal :
– Increase the permeability of the bleb's wall
– Produce a more diffuse, better functioning bleb.
• Slit lamp / Operation theatre
– Informed consent
– Antibiotic drops
– Clean-drape if in OT
– Topical anaesthetic
– Lid speculum

34. • 25G needle (sturdier)
• 5 to 10 mm temporal from the bleb site
• Posteriorly directed, bevel up, tangential to sclera
• Advanced in the bleb with a twisting motion
• Subconjunctival fibrosis cut with firm back & forth ,
side to side motions till eye softens
• Can enter AC (pseudophakes; flat bleb)
• Avoid conjunctival buttonhole

35. • Can be accompanied with
– Subconjunctival injection of MMC (0.1 mL 0.04
mg/mL)
– 5-FU (5mg in 0.1 mL lignocaine) given
• 180 degrees away from the bleb
• 15 to 50 mg in 3-10 injection over 3 weeks
• Antibiotic/steroid drops for 2-3 weeks
• Digital massage

36. COMPLICATIONS
• HYPOTONY
– Buttonhole
– Aggressive neeedling
• BLEBITIS
• ENDOPHTHALMITIS
• EPITHELIAL TOXICITY (5-FU)
• ENDOTHELIAL TOXICITY (MMC)

37. • MMC drops comparable to 5-FU injections in
terms of
– IOP, bleb appearance,
– success rate, (68.4% MMC, 77.8% 5-FU)
– number of glaucoma medications,
– visual outcome,
– overall complications
Pakravan M, Miraftabi A, Yazdani S.Topical Mitomycin-C versus Subconjunctival 5-
Fluorouracil for Management of Bleb Failure. J Ophthalmic Vis Res. 2011
Apr;6(2):78-86.

38. TOPICAL MMC
• SIDE EFFECTS
– Local irritation, hyperaemia,
– Epiphora (Punctal stenosis),
– Allergy,
– Keratoconjunctivitis
– Corneal abrasion (superficial punctate keratitis)
– Cataract,
– Persisting keratoconjunctivitis,
– Limbal stem cell deficiency
Shields CL, Naseripour M, Shields JA. Topical mitomycin C for extensive, recurrent conjunctival-corneal squamous cell carcinoma. Am J
Ophthalmol 2002;133:601–6.
Fucht-Pery J, Rozenman Y. Mitomycin C therapy for corneal intraepithelial neoplasia. Am J Ophthalmol1994;117:164–8.
Song JS, Kim JH, Yang M, et al. Mitomycin-C concentration in cornea and aqueous humor and apoptosis in the stroma after mitomycin-C
application. Cornea 2007;26:461–

39. • Subconjunctival 5-FU application more effective
therapy than bevacizumab for needling
procedures in failed trabeculectomy blebs.
Simsek T1, Cankaya AB, Elgin U. Comparison of needle revision with subconjunctival
bevacizumab and 5-fluorouracil injection of failed trabeculectomy blebs. J Ocul Pharmacol Ther.
2012 Oct;28(5):542-6.

41. OTHER COMPLICATIONS
• UVEITIS
• HYPHEMA
• DELLEN
• SNUFF OUT PHENOMENON

42. LATE COMPLICATIONS
• Thinning and leaking bleb
• Large overhanging bleb
• Bleb related infections
– Blebitis
– endophthalmitis
• Cataract

43. INTRAOPERATIVE COMPLICATIONS

44. BUTTONHOLE OF
CONJUNCTIVA
• Avoid toothed forceps
• Avoid cutting needles
• Subtenon lignocaine
• Corneal traction sutures
• Repair (layered)
• Avoid antimetabolite over the defect (sodium
hyaluronate)
• New site
• Bandage contact lens

45. SCLERAL FLAP TEAR
• Avoid very thin flaps (half or more)
• Gentle handling
• Avoid cautery at the edges (retraction)
• Donor sclera / pericardium
• Limbal hinge by 10-0 nylon
• New site

46. LENS INJURY and VITREOUS PROLAPSE
• Most commonly during block removal
• During peripheral iridectomy
• Kelly’s punch instead of Vanna’s scissors
• Constrict pupil before PI
• Oblique paracentesis
• Merocel sponge assisted vitrectomy (avoid
automated vitrectomy)
• Tighter flap closure

47. HYPHEMA
• Predisposing conditions
• Irrigate with cold irrigating solution
• Epinephrine

48. SUPRACHOROIDAL HEMORRHAGE
• Preoperative intraocular pressure
• Hypertension and atherosclerosis
• Sudden decompression
• Immediate closure
• Posterior sclerotomy