Complications of trabeculectomy

COMPLICATIONS OF TRABECULECTOMY

Sumeet AgrawalPG 3

UCMS and GTB Hospital, Delhi

INTRAOPERATIVE POSTOPERATIVEEARLY LATE

Buttonhole of conjunctivaHYPOTONY

-Flat anterior chamber-Deep anterior chamber

Thinning and leaking bleb

Scleral flap tearELEVATED 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

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

MEASURING IOP

• Digital palpation

• Avoid filtering site

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

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

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

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)

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

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

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)

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

Delayed Suprachoroidal

Hemorrhage

• Associated symptoms:– Severe pain

– Nausea

– Marked sudden diminution of vision

– Manage IOP

– Wait for clot lysis (14 days)

– Drain

ELEVATED IOP WITH DEEP AC

• INADEQUATE FILTRATION

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

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

SEEK OUT THE CAUSE

• BLOCK OF INTERNAL OSTIUM

• EXTERNAL BLOCK (most common)

• INTERNAL BLOCK

– Iris

– Ciliary body

– Vitreous

– Blood clot

– Fibrin

• Gonioscopic evaluation

• EXTERNAL BLOCK

– Tenon’s cyst

– Episcleral scarring

• Careful slit lamp evaluation

MANAGEMENT

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

• 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 episcleralblood 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

• Without magnification

– Edge of a four-mirror gonioprism

– Hoskins laser suture lens

• High-magnification suture lysis contact lenses

– Mandlekorn lens

– Blumenthal lens

– Ritch lens

HOSKINS LENS

• 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

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.

• 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.

• 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.

• 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.

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

• 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

• 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

COMPLICATIONS

• HYPOTONY

– Buttonhole

– Aggressive neeedling

• BLEBITIS

• ENDOPHTHALMITIS

• EPITHELIAL TOXICITY (5-FU)

• ENDOTHELIAL TOXICITY (MMC)

• 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.

TOPICAL MMC

• SIDE EFFECTS– Local irritation, hyperaemia,

– Epiphora (Punctal stenosis),

– Allergy,

– Keratoconjunctivitis

– Corneal abrasion (superficial punctate keratitis)

– Cataract,

– Persisting keratoconjunctivitis,

– Limbal stem cell deficiencyShields 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–

• 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 subconjunctivalbevacizumab and 5-fluorouracil injection of failed trabeculectomy blebs. J Ocul Pharmacol Ther.

2012 Oct;28(5):542-6.

OTHER COMPLICATIONS

• UVEITIS

• HYPHEMA

• DELLEN

• SNUFF OUT PHENOMENON

LATE COMPLICATIONS• Thinning and leaking bleb

• Large overhanging bleb

• Bleb related infections

– Blebitis

– endophthalmitis

• Cataract

INTRAOPERATIVE COMPLICATIONS

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

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

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

HYPHEMA

• Predisposing conditions

• Irrigate with cold irrigating solution

• Epinephrine

SUPRACHOROIDAL HEMORRHAGE

• Preoperative intraocular pressure

• Hypertension and atherosclerosis

• Sudden decompression

• Immediate closure

• Posterior sclerotomy