Downloaded 284 times
Uploaded bySumeet Agrawal
Managing the failing bleb
This document provides guidance on managing failing blebs after glaucoma surgery. It discusses risk factors for bleb failure, the histology of functioning vs failed blebs, typical appearances of failed blebs, identifying the cause of failure as internal or external blockage, and various management techniques. These include increasing digital pressure, medications, laser suture lysis, and bleb needling with or without anti-metabolites like mitomycin C or 5-fluorouracil to restore bleb function and control intraocular pressure. Complications of bleb needling are also reviewed.
More Related Content
Similar to Managing the failing bleb
Managing the failing bleb
- 1. MANAGING THE FAILINGBLEB • RECOGNISE FAILURE • IDENTIFY THE CAUSE • DEAL WITH HIGH IOP • RESTORE BLEB FUNCTION
- 2. Risk factors forfailing bleb • Young age • Males • Black race • Congenital and juvenile glaucoma • Subconjunctival hemorrhage • Excessive inflammation – Long-term topical glaucoma therapy – Traumatic glaucoma – NVG • Reaction to sutures
- 3. HISTOLOGY • EPITHELIUM – Similarin both functioning and failed blebs • SUBEPITHELIAL CONNECTIVE TISSUE – Loosely arranged tissue with clear spaces – Dense collagenous tissue with no spaces
- 4. Elevated IOP witha 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
- 5. 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
- 6. SEEK OUT THECAUSE • BLOCK OF INTERNAL OSTIUM • EXTERNAL BLOCK (most common)
- 7. • INTERNAL BLOCK –Iris – Ciliary body – Vitreous – Blood clot – Fibrin • Gonioscopic evaluation • EXTERNAL BLOCK – Tenon’s cyst – Episcleral scarring • Careful slit lamp evaluation
- 8.
- 9. RAISED IOP • Digitalocular 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
- 10. • Frequent anti-inflammatorytherapy • 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
- 11. • Without magnification –Edge of a four-mirror gonioprism – Hoskins laser suture lens • High-magnification suture lysis contact lenses – Mandlekorn lens – Blumenthal lens – Ritch lens
- 12.
- 13. • 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
- 16. 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.
- 17. • Ewing andStamper3 – 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.
- 18. • Mardelli etal.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.
- 19. • Risk factorsfor 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.
- 20. 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
- 21. • 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
- 22. • Can beaccompanied 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
- 23. COMPLICATIONS • HYPOTONY – Buttonhole –Aggressive neeedling • BLEBITIS • ENDOPHTHALMITIS • EPITHELIAL TOXICITY (5-FU) • ENDOTHELIAL TOXICITY (MMC)
- 24. • MMC dropscomparable 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.
- 25. TOPICAL MMC • SIDEEFFECTS – 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–
- 26. • Subconjunctival 5-FUapplication 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.