Surgery in open angle glaucoma
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Surgeries for open angle glaucoma were discussed, including trabeculectomy. Trabeculectomy involves making a conjunctival flap, applying antimetabolites, excising a block of tissue from the eye, and suturing the scleral flap. Potential complications include shallow anterior chamber, low or high eye pressure, infection, and visual loss. Careful postoperative monitoring and treatment are important to manage complications while lowering eye pressure to prevent further glaucoma damage.
Surgery in open angle glaucoma
- 1. Surgeries in open angle glaucoma Presenter: Dr.Aditi Singh
- 2. Indications: 1.Documented visual field and optic nerve damage, despite maximum tolerated medications and laser therapy. 2. Anticipated progressive damage or intolerably high IOP. 3. Combined with cataract procedure if there is borderline IOP control or advanced damage,.
- 3. : guarded (trabeculectomy) Penetrating filterationg surgeries full-thickness Nonpenetrating filtration surgery(NPFS) Glaucoma Drainage Devices (GDD) Recent advances in glaucoma surgeries
- 4. Full-Thickness Filtration Procedures 1.Thermal sclerostomy (scheie Procedure). 2.Sclerectomy 3.Trephination 4.Iridencleisis Rarely performed today.
- 5. 1.Thermal sclerostomy (scheie Procedure): • Limbal-based conjunctival flap. • Light cautery applied to the sclera in 1X 5 mm area , behind corneolimbal junction. • 5 mm limbal scratch incision is made through the cauterized area. • Cautery is applied to the lips of the incision , until the wound edges separate by atleast 1 mm.
- 6. 2. Sclerectomy: Posterior lip sclerectomy: • Ab-externo incision- just behind the point of reflection (using a limbal- • based flap) of the conjunctiva at the anterior limbus. • Length - 3–4 mm • Sclerectomy - 1-mm scleral punch • Peripheral iridectomy • Closure Anterior lip sclerectomy: • Incision - at the corneoscleral sulcus • Excise the 1-mm semicircle of tissue. • Button holing of the conjunctival flap .
- 7. • 3.Trephination: • Corneoscleral trephination, using a 1–2-mm glaucoma trephine, is a difficult procedure. • Performed only occasionally. 4.Iridencleisis: • Wedge of iris is incarcerated into the limbal tissue . The presumed mechanism was a ‘wicking’ of aqueous by the iris tissue. • However, reports of chronic iritis, infection, and sympathetic ophthalmia led to other techniques being explored
- 8. Complications: • Shallow (or flat) anterior chambers: • Peripheral anterior synichae, • Corneal decompensation. • Premature cataract formation, • and infections.
- 9. Guarded Filtration Procedure: Trabeculectomy : Introduced by: Cairns in the 1960s. Indications: • Intraocular pressure too high to prevent further 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, refusal. • Intolerance to medical therapy due to side effects. •
- 10. Anesthesia • General anesthesia • Local : Retrobulbar local block, peribulbar block , subtenon’s, or • Topical anesthesia in selected cases.
- 11. Technique Clear corneal traction suture: •7-0/ 8-0 vicryl • half thickness • 2 mm anterior to the limbus. The Conjunctival Flap: Site: Superior and slightly nasal. Both limbus and fornix based conjunctival flaps
- 12. Limbus-Based Flap Advantages: • allows tight wound closure. • relatively easy to master. Disadvantages: • ‘migrates’ towards the limbus. • more chances of incapsulated bleb. Fornix-Based Flap Advantages: • easier exposure of the surgical site • reduced handling of the conjunctival flap. Disadvantages: • longer operative time. • may leak in the postoperative period and fail to retain aqueous, so that the bleb flattens.
- 14. Antimetabolites : Agents 5-FU inhibits DNA synthesis and RNA function; usual intraoperative dose is 50 mg/mL. MMC alkylates DNA and inhibits DNA and RNA synthesis; usual dose is 0.2–0.4 mg/mL. Prepare sponges: cut to size and then soaked in the antimetabolite Place sponge under the conjunctival flap (and under scleral flap in resistant cases) for appropriate duration (5 min for 5-FU; 2–4 min for MMC)
- 15. Scleral Flap
- 16. The anterior chamber is entered under the flap, and a block of tissue approximately 1.5–2.5 mm wide is removed with a Descemet’s punch just anterior to the scleral spur. Removal of the trabeculectomy block too posterior to the scleral spur offers no advantage and increases the risk of hemorrhage Peripheral iridectomy.
- 17. Flap Suturing The scleral flap is reapproximated with 9-0 or 10-0 nylon sutures . Releasable suture Peng Khaw’s adjustable suture technique allows a titrated outflow A careful running suture in two layers, first closing Tenon’s and then its overlying conjunctiva at the limbus.
- 18. Postoperative lasering, adjustment, or release of sutures : Argon green, argon blue-green, diode, YAG laser or krypton red laser. Four-mirror Zeiss gonioprism or with the Hoskins laser suture lens . High-magnification suture lysis contact lenses are commercially available (e.g., Mandlekorn lens or Blumenthal lens )
- 19. Complications and management: Complications Intra-operative Post-operative Early Late
- 20. Intraoperative Complications Preoperatively: Identify the risk factors. Conjunctival button Discontinuation of anticoagulants. Intraoperatively: Topical apraclonidine 1 % or adrenaline Minimal handling of tissues Maintain intraoperative IOP. Management : All wounds should be promptly closed Reformation of the anterior chamber SCH extensive: drainage of blood by • Choroidal hole expansion: secure the wound; Perform posterior Scleral sclerotomy flap damage that does not perforate choroid , Vitreous loss administer atropine. • Suprachoroidal hemorrhage:Recognize vitreous loss; secure the wound; perform posterior sclerotomy over choroidal elevation area to drain blood; administer atropine Bleeding:Conjunctiva, sclera,iris or suprachoroidal Flat anterior chamber:choroidal hemorrhage , choroidal expansion,aqueous misdirection Prevention: non toothed forceps Before or after sclerostomy Management: small : spontaneous healing (with hold steroid drops) focal (1-2mm) : closure with 10-0 nylon Management: Before sclerostomy: new site After sclerostomy : Minor : suturing with 10-0 nylon Severe : scleral patch graft , tenon’s capsule , fascia lata Causes: thin sclera( buphthalmic eye), aphakia, post trauma, lens dislocation. Management : anterior vitrectomy emergency pars plana sclerostomy
- 21. Postoperative complications Early Shallow AC Low IOP High IOP Early Infection Wipe out phenomenon Blebitis Endophthalmitis
- 22. Shallow AC Low IOP Formed Bleb Flat Bleb Over filtration Causes: •Antimetabolites •Loose sceral flap sutures •Full thickness procedures Management : •Cycloplegics •+/- aqueous suppressants •Decrease steroids •Pressure patching •Simmons shell, SCL Flat AC: •Reformation : •Visoelastics / BSS •Large choroidal effusions may need drainage
- 23. Shallow AC Low IOP Flat Bleb Pressure patch Wound Leak Temporary tapering of topical steroids Large diameter SCL Cyanoacrylate Glue Injection of autologous blood Surgical repair (larger holes) Conjunctival autograft Indian J Ophthalmol. 2011 January; 59
- 24. Shallow AC Low IOP Serous choroidal detachment •Due to Hypotony •Prolongs the hypotony •Vicious cycle Management : •Cycloplegics , topical steroids •Surgery : •Kissing choroidals •Flat AC , compromised cornea •Eyes with chronic angle closure glaucoma with extremely shallow AC, after trabeculectomy Dellaporta Technique
- 25. Low IOP CB Shutdown • Excessive inflammation Steroids Atropine Cyclodialysis cleft • Identify with gonio or UBM • Atropine, decrease steroids • Argon laser with Goldmann lens • Avoid beta blockers, CAI inhibitors • Treat the scleral region of the cleft • For large cleft, definitive management is surgical repair
- 26. Shallow AC High IOP Pupillary block Suprachoroidal heamorrhage Malignant glauma • Non patent PI • Management: • Dark choroidal swelling • Typical symptoms: • sudden loss of vision Laser PI Mydriasis Topical steroids pain nausea and/or vomiting • Very shallow or flat central AC • Look for patent iridotomy • Aqueous suppressants • Cycloplegics, topical steroids • YAG anterior vitreous face (aphakic/pseudophakic) • Pars plana vitrectomy • Vigorous surveillance • Attention to the fellow eye. • Diagnosis • Indirect • B-scan • Management • Aqueous suppressants, • Hyperosmotics ,Pain relief, • Drainage
- 27. • Filtration failure: • Obstruction of the sclerostomy and scleral flap may be internal (incarceration of iris, ciliary processes, or vitreous), scleral (fibrin, blood), • or external (overly tight scleral flap sutures). • Consider bleb massage, removal of releasable suture(s), loosening of adjustable suture(s), and argon laser lysis of fixed suture(s). • Visual loss: • Wipe-out of the remaining field may occur in the presence of a vulnerable optic nerve (associated with increased IOP or hypotony) or • Hypotonous changes may lead to reduced acuity (e.g., from maculopathy).
- 29. Infection Blebitis : - a painful red eye, possibly with mucus discharge and photophobia. The bleb is milky with loculations of pus, conjunctival injection (especially around the bleb), and increasing IOP. Identify organism with culture/swab of bleb. Treat with intensive topical antibiotics and systemic antibiotics. Consider addition of topical steroids after 24 hours and add mydriatic if AC activity is present.
- 30. Endophthalmitis: Clinical features c are the same as for blebitis but are more severe, with decreased VA and vitritis. Investigate and treat as for other postoperative endophthalmitis. However, endophthalmitis occurring after trabeculectomy tends to run a more aggressive course with a worse prognosis than after cataract surgery.
- 31. Late postoperative complications a)Leaking bleb: antimetabolite-associated or nonguarded filtration surgery Small leaks : often resolves Otherwise, : consider bandage contact lens, autologous blood injection, compression sutures, or refashioning of bleb. b)Infection: (blebitis/endophthalmitis). c)Visual loss: Cataract .There can also be induced astigmatism, maculopathy, and glaucomatous progression.
- 32. Failure of the Filtering Bleb: Early Failure of Filtering Bleb: Presentation: high IOP, deep anterior chamber, and low and hyperemic bleb. Preventive measures: Postoperative topical steroids are routinely used. The use of antifibrotic agents. Manoeuvres to improve bleb function: Digital ocular compression and focal compression Laser suture lysis or removal of an externalized releasable suture
- 33. Late Failure of Filtering Bleb: Most common cause : subconjunctival-episcleral fibrosis . Factors accelerating fibrosis are: black race, childhood, postoperative subconjunctival hemorrhage, the presence of reactive sutures, and inflammation. “Warning signs ” - increased bleb vascularization, bleb inflammation, and/or bleb thickening, high IOP. Treatment : In cases of subconjunctival-episcleral fibrosis - an external revision or bleb needling can be tried along with antimetabolites.
- 34. Encapsulated Blebs: Localized, elevated, and tense filtering blebs, with vascular engorgement of the overlying conjunctiva and a thick connective tissue Tenon’s cyst Second to fourth postoperative week as a tense, “tight-appearing”bleb. Temporary IOP reduction : aqueous suppressants . Bleb needling with antimetabolites is an option in case of sustained raised IOP. Failing all measures, a surgical bleb revision (partial/ complete cyst excision) or repeat trabeculectomy may be required, especially in cases of multiloculated cysts.
- 35. Other bleb related complications:
- 36. Complications…. Cataract: flat anterior chamber reformation of the anterior chamber with air lens trauma inflammation the use of – steroids , intraoperative MMC Ptosis : superior rectus bridle suture MMC damage to superior rectus. Astigmatism: large scleral flaps. radial flap sutures.
- 37. Glaucoma Drainage Devices Indications: • Failed trabeculectomy • Extensive conjunctival scarring • Likely failure of trabeculectomy, including - • Neovascular glaucoma • Uveitic glaucoma • Glaucoma associated with penetrating keratoplasty • ICE syndrome • Epithelial downgrowth • Refractory pediatric glaucoma
- 38. Valved Two main classifications of implants • Only drains fluid at a certain IOP. • Valve opens and fluid is drained into a reservoir where it is absorbed by surrounding tissues(e.g., Krupin or Ahmed valves). Non- Valved • Nonvalved implants or open tube drainage devices provide little resistance to aqueous flow during the early postoperative period until a fibrous capsule forms around the plate.(e.g., Molteno or Baerveldt implants).
- 39. RESERVOIR PLACEMENT • The scleral bed is exposed with a fornix-based conjunctival flap. • Superior quadrant (supero temporal quadrant) is preferred. • All plates have eyelets on the anterior edge for securing the implant to the sclera with a non-absorbable (suture#6-0 Mersilene ). • The plate should be positioned posterior to the insertion of the rectus muscles; 8–10 mm is measured with calipers from the limbus to the central plate edge.
- 40. TUBE ENTRY. The tube is trimmed so that there is a bevel facing anteriorly and 2 to 3 mm will appear within the anterior chamber . • After scrutiny for the ideal tube entry site, a 23-gauge needle is passed through the limbus to create a tight entry site. The tube tip should not be touching either the cornea or lens. • Tube is secured to sclera using 9-0/10-0 nylon suture.
- 41. WOUND CLOSURE Some surgeons construct a scleral tunnel to cover the tube. Usually the tube is covered with some sterile biodegradable tissue, such as donor sclera, pericardium, or dura, all of which seem to be equally efficacious. The conjunctiva is repositioned to carefully cover the tube and overlying patch graft.
- 42. Modifications • To avoid overfiltration and hypotony in the early postoperative period, a two-stage implantation or temporary ligation of the tube may be utilized. • Two-stage implantation: • Tube is folded back and placed under the patch graft or beneath an adjacent rectus muscle and can be attached to the episclera with a nylon or silk suture to facilitate identification. • In the second stage, the tube is inserted 4–6 weeks later after a fibrous capsule (pseudocyst) has formed around the plate.
- 43. Modifications……. • Transient flow restriction techniques : • Aqueous flow can be limited in the early postoperative period by internal and external occlusion techniques. Rip-cord suture Prolene suture ligature at tip of tube
- 44. Complications Excessive drainage : leakage around or down the tube if the occluding suture is loose and results in hypotony and a shallow anterior chamber. Malposition : endothelial or lenticular touch . Tube erosion : through the sclera and conjunctiva . Early drainage failure : blockage of the end of the tube by vitreous, blood or iris tissue . Late drainage failure : Excessively thick fibrous capsule. Indian J Ophthalmol. 2011 January; 59
- 45. Complications…………. Diplopia: mechanical involvement of the superior oblique muscle if the implant impinges on the superonasal quadrant, or to the elevated space-occupying bleb that can form over the plate, causing restriction and muscular limitation.
- 46. NONPENETRATING GLAUMA SURGERY(NPGS) Indications 1.All open-angle glaucomas (especially if): Early surgical intervention required. Monocular patient. Large diurnal fluctuations . 2.High risk of choroidal effusions or hemorrhages. 3.High risk of postoperative hypotony. 4.Uveitic glaucoma without extensive PAS. 5.Congenital glaucoma.
- 47. NPGS Deep Sclerectomy Viscocanalostomy
- 48. Deep sclerectomy: The superficial scleral flap is one-third of the scleral thickness and is dissected 1--1.5 mm into clear cornea. The sclera is exposed and a superficial scleral flap measuring 5 5 mm is dissected, including one-third of the scleral thickness The When deep the sclerectomy anterior dissection measures is 4 completed, 4 mm and the sclera is dissected, deep scleral leaving flap about is removed 5% of by sclera cutting over anteriorly the choroid first and with ciliary the diamond body. blade. The inner wall of the Sclemm’s canal and the juxtacanalicular trabeculum are peeled off using fine forceps. TThhee A collagen s Sclcehrolceomrnmea’lsdciassnecatli implant is oins sutured iisd pernotloifniegded. in the anteriorly scleral 1--1.5 mm bed. using a ruby blade or a crescent knife, in order to remove the sclerocorneal tissue behind the anterior trabeculum and Descemet’s membrane. Surv Ophthalmol 53 (6) November--December 2008
- 49. Viscocanalostomy After excision of the deep tissue containing a portion of Schlemm’s canal, the remainder of Schlemm’s canal can be accessed by inserting a fine-tipped cannula into the exposed ostia of Schlemm’s canal. Injection of viscoelastic material into Schlemm’s . Repeated 6-7 times. Injection of viscoelastic beneath the superficial scleral flap. Suture the superficial scleral flap tightly.
- 50. Advantages Disadvantages No sudden decompression of anterior chamber Suprachoroidal hemorrhage less likely Serous choroidal detachment less likely Reduced risk of prolonged hypotony Less likely to get filtering bleb Less chance of bleb leak – early or late Less chance of blebitis, endophthalmitis Contact lens wear less likely to be problematic Bleb dysthesia rare Less intraocular inflammation Less chance of intraocular bleeding More rapid visual rehabilitation postoperatively Technically more difficult. Takes longer in the operating room Requires some specialized instrumentation. About 10% have actual perforation into anterior chamber requiring iridectomy. Intraocular pressure less likely to be lowered sufficiently in advanced glaucoma. Pressure lowering may not last as long It is important to remember that these procedures are in evolution and refinements are necessary.
- 51. Complications of deep sclerectomy Conversion to trabeculectomy because of penetration through trabecular meshwork. Scleral ectasia. Iris incarceration, prolapse or peripheral anterior synechiae. Descemet’s detachment. Hypotony. Hyphema. Serous choroidal detachment. Vitreous hemorrhage. Late anterior chamber bleeding during gonioscopy.
- 52. Contraindications: 1.Trabecular meshwork obstructed: • Extensive synicheal angle closure. • Neovascular glaucoma. • Occludable angle. 2.Altered anatomy: • Thin sclera. • Significant limbal scarring. 3. Post laser trabeculoplasty. 4.Angle recession glaucoma.
- 53. Recent advances in glaucoma surgeries I. The Ex-Press mini glaucoma shunt II.Nonpenetrating Ab Externo Schlemm’s Canaloplasty III.Ab Interno Devices: The Trabectome and Micro-bypass Stent IV.The Gold Microshunt: A Suprachoroidal Device
- 54. The Ex-Press mini glaucoma shunt Originally developed to be implanted subconjunctivally through the limbus Redesigned - trabeculectomy style scleral flap. Long term success – yet to be established.
- 55. Canaloplasty Nonpenetrating Ab Externo Schlemm’s Canaloplasty
- 56. Once the A Secnhtlierme 10–0 Prolene tmchie’rs ctcruaamnbaefcle suture uirsl eoendxepcseoc seoemfd is tied e twthietwh around ci naad ncorawels c(hTeanDstW the bbl)ea end ecdnaen c baen of sneeunla. the device ted with the iScience prior microcatheter, to its retraction. the device is primed with ophthalmic viscosurgical device, which can be seen emerging from the tip of the device on the right. A superficial Deeper spcalerraabloflliacp f lias pc roefa atepdp rwoixthim salitgehlyt l2y5 s0m- atoll e3r0 d0i-m2men tshiiocnksn tehssa,n 4 t.5h a t4 .5 mm, is made. Once the suture has been delivered and cut away from the microcatheter, the two cut ends must be matched and tied together. of the superficial flap. •The superficial scleral flap is then placed back into position and sutured interrupted 10–0 nylon sutures. • High viscosity sodium hyaluronate is then injected under the superficial scleral flap using the viscocanalostomy cannula in order to maintain the scleral lake – the space where aqueous humor that has percolated through the TDW accumulates and is then absorbed into episcleral, scleral, and choroidal circulation. • The conjunctiva is then closed with a 10–0 Vicryl suture. Techniques in Ophthalmology 5(3):102–106, 2007
- 57. Advantages: Drawbacks: • Absence of vision-threatening complications such as: • Choroidal detachments, • Shallow or collapsed anterior chambers, and • Prolonged hypotensive periods. Descemet’s tear. Elevated postoperative pressure ( possible inflammatory changes in the canalicular structures). Difficult procedure, which needs an experienced deep sclerectomy or viscocanalostomy surgeon.
- 58. Shunts into schlemm’s canal The Trabectome Micro-bypass Stent
- 60. •A clear corneal near-limbal 1.6-mm keratome incision is made. Viscoelastic may or may not be necessary to allow safe insertion of the instrument tip to allow infusion flow and anterior chamber stability. •Surgical tip is advanced under gonioscopic control to engage nasal meshwork before activating aspiration and ablation by progressively depressing the foot pedal and rotating the tip parallel to the iris just anterior to the scleral spur. •Ablation with continual infusion and aspiration is performed along an arc of 30 ° to 60°. Microelectrocautery handpiece designed to ablate trabecular meshwork and Schlemm’s canal inner wall tissue over an area of several clock hours.. The device is a disposable handpiece that is activated by foot pedal control connected to a console that allows the surgeon to adjust infusion, aspiration, and dissipated electrosurgical energy. Trans Am Ophthalmol Soc v.104; Dec 2006
- 62. Two functions: 1. providing direct access of aqueous into the schlemm’s from the anterior chamber (the snorkel effect) and 2. pushing the anterior trabecular meshwork away from the posterior wall of Schlemm’s canal.
- 64. Arch Ophthalmol. 2009;127(3):264-269. The Gold Microshunt: A Suprachoroidal Device
- 65. Arch Ophthalmol. 2009;127(3):264-269. Postoperative clinical image of a patient after Gold Micro Shunt implantation. Note the good position of the shunt in the anterior chamber (A), with no shunt-corneal or shunt-iris touching, as seen in the gonioscopic view (B).
- 66. Endoscopic Cyclophotocoagulation : Indications: •In cases of refractory glaucoma •Patients on maximum medical therapy showing continued progression of disease were often considered as appropriate candidates. •Patients who had failed filtration surgery or were considered at high risk for failure or complications post-traditional filtration procedures. •Better visualization of the tissue being treated •Less destructive method of applying the laser,
- 67. ECP employs - 810-nm diode laser, allows the surgeon to precisely aim and deploy the laser to cause effective cycloablation while avoiding damage to adjacent structures. Extensive contraction of the ciliary processes was observed as well as changes to the ciliary body epithelium. There was much less destruction (if any) to the ciliary body muscle
- 68. Procedures of historical importance: Cyclodialysis was once a mainstay in the management of aphakic glaucoma. Its principle was to mechanically disrupt the iris root at its scleral spur attachment so that a cleft was created between the anterior chamber and suprachoroidal space. Significant hemorrhage was almost unavoidable, as was hypotony resulting from an overfunctioning cleft, which if spontaneously healed would lead to a precipitous rise in IOP. Other common complications included cataract and stripping of Descemet’s membrane. With so many more physiologic options for surgical control of the IOP, this procedure is now of historical relevance only.
- 69. References 1.Becker-Shaffer's Diagnosis and Therapy of the Glaucomas, 8e Robert L. Stamper MD , Marc F. Lieberman MD , Michael V. Drake MD 2. Shields Textbook of Glaucoma (Allingham, Shields' Textbook of Glaucoma) Karim F. Damji , Sharon Freedman , Sayoko E. Moroi (Editor), M. Bruce Shields. 3. Kanski's Clinical Opthalmology: A Systematic Approach 6th Ed .Mohd Zafrullan Zamberi Ophthalmology. 4. Oxford American Handbook of Ophthalmology. James C. Tsai, MD, MBA. 5. The glaucomas: concepts and fundamentals.Tarek M. Eid ,George L. Spaeth. 6. The Glaucoma Book A Practical, Evidence-Based Approach to Patient Care Editors Paul N. Schacknow , John R. Samples 7. Yanoff & Duker: Ophthalmology, 3rd 8. The role of artificial drainage devices in glaucoma surgery(Indian Journal of Ophtahlmology.)1998(46):1,41-46.R Thomas, A Braganza, G Chandrasekhar, S Honavar, AK Mandal, R Ramakrishnan, BS Rao, R Sihota, NN Sood, B Shantha, L Vijaya .Christian Medical College, Vellore, Chennai, India. 9. Nonpenetrating Glaucoma Surgery.Efstratios Mendrinos, Andre´ Mermoud,