MIGS: Will Glaucoma Become a Surgical Disease - PDF Document

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  1. MIGS: Will Glaucoma Become a Surgical Disease Richard Lewis, MD Sacramento, CA

  2. Disclosures Aerie • Allergan • Alcon • Aquesys • AVS • Glaukos • Ivantis •

  3. Which eye had surgery vs eyedrops? Medical Rx: 2 Drops S/P Glaucoma Surgery 12 mmHg 12 mmHg (Photo from Reay Brown)

  4. Why Should Glaucoma Be a Surgical Disease?  Simplicity  Safe and effective surgery avoids… – Eye Drops –Side effects (esp to ocular surface) –Compliance –Recurring expense

  5. Selective and Argon Laser Trabeculoplasty At 1 year, 82% of patients who underwent SLT remained on the same number of medications (2.6) • 18% required an additional medication • 100% of patients remained on the same number of medications or increased their medications • More patients in the ALT group than the SLT group required an additional medication at 1 year ALT Group SLT Group SLT group members maintained on the same number of medications at 1 year after treatment 18% 29% Eyes that remained on the same number of medications 82% 69% Eyes that required one additional medication SLT group members had one additional medication at 1 year after treatment Cantor, L. B., L. J. Katz, et al. Economic evaluation of medication, laser trabeculoplasty and filtering surgeries in treating patients with glaucoma in the US. Curr Med Res Opin . 2008;24(10): 2905-18. 5

  6. MIGS: A New Perspective  Who is a candidate?  What justifies the procedure?  How to start implanting? 6

  7. R. Stegmann’s View of the Canal

  8. MIGS: What is it? –Minimally Invasive Glaucoma Surgery – Ab interno micro-incision procedures – Lower risk – Earlier intervention – Minimal additional technology – Does not preclude other glaucoma surgery

  9. MIGS: Mechanism of Action 1. Subconjunctival Aquesys (Xen) – 2. Canal Glaukos (iStent) – Ivantis (Hydrus) – 3. Suprachoroidal – Transcend (CyPass) – Glaukos (G3) Trabectome is disruptive to the TM/canal and, thus, not a MIGS procedure

  10. Glaucoma Surgery Profile MIGS Mild to moderate disease  Open angles  Modest IOP target (15-16)  Low risk  Long term data lacking 

  11. Glaucoma Surgery Profiles MIGS Trab or Tube Mild to moderate disease More advanced disease   Open angles Open or closed angles   Lower IOP target (<13)  Modest IOP target (15-16)  Higher risk  Low risk  Recognized long term effect (s)  Long term data lacking 

  12. Variables to Consider 1. Efficacy 2. Risk/complications 3. Technical ease 4. Duration 5. Cost to physician/ASC/hospital 6. Reimbursement

  13. Canal Surgery Milestones 1962: Sinusotomy – Krasnov • 1968: Trabeculectomy – Cairns/Watson • 1978: Non perforating trabeculectomy- Zimmerman • 1982: Deep sclerectomy- Fyodorov • 1993: Viscocanalostomy – Stegmann • 2001: Aquaflow Collagen Implant • 2004: Canaloplasty – Stegmann, Lewis • 2012: iStent (Trabecular bypass) – Hill •

  14. Clinical Development Milestones 1999 – Stegmann: viscocanalostomy 2001 - Ultrasound imaging to localize canal and outflow system 2003 – Development of flexible 250u lumen microcanula 2004-05 -Viscodilation and suture stent passage – Canal tensioning or Canaloplasty Illuminating Tip of Microcannula in Schlemm’s Canal

  15. Canaloplasty: Mechanism of IOP Reduction 1. Aqueous flow through Trabecular Descemet’s membrane (or window) 2. Aqueous re-absorption – Subconjunctival filtering bleb – Through canal and collectors

  16. Canaloplasty

  17. Canaloplasty – Surgical Site Descemet’s Window ~0.3 mm deep with FLOW Slight inward dimpling of TM from suture Clear TM with FLOW Clean, open ostia Choroid visible through remaining sclera ~0.5 mm ledge for outer flap seal

  18. Canaloplasty: Indications 1. Open angle glaucomas including PDS and PXE 2. Expect Trabeculectomy to Fail • Failed trabeculectomy or hypotony in fellow eye • Significant conjunctival disease 3. Concerned about further loss of vision • High myopia and contact lens wearers • Immunosuppressive treatments • Anti-coagulation

  19. Aussie: Case Report 47 y/o man on 4 meds s/p SLT – High (-9.0) myope – Ocular surface disease from long term glaucoma meds – IOP: 18-20 – Pachy: 490 – Advanced cupping with sup arcuate defect OU

  20. Canal vs Trab: Ayyala et al Ophthalmology 2011

  21. Canal vs Trab: Ayyala et al Ophthalmology 2011

  22. Canaloplasty: Challenges 1. “Learning curve” - finding the canal 2. Canal access in various glaucomas 3. Magnitude of IOP reduction 4. Long term efficacy

  23. JK: Case Study  56 y/o MD with high myopia and glaucoma since 2007, complains of ocular irritation and redness  History: – High myopia (-18.0) – wears GP CL – 2006: Glaucoma, initial IOP 23/27 – 2007: Phaco/IOL OS – 2009: Trab/5FU (post op hypotony) – 2009: Head MRI, blood studies all WNL  Meds: Azopt OU, Travatan OU, Timolol OU 23

  24. JK: Case Study  Exam: OD OS – Acuity -18.00CL=20/30 20/20 – SLE 2+ follicles, redness OU – 2+ NS, PSC PC IOL – IOP 11 11 – Fundus 0.8 cup 0.9 cup pale – Pachy 606 590 24

  25. JK: Case Study 25

  26. JK: Case Study 26

  27. JK: Case Study  Problem List – High myopia – POAG – progression, optimal IOP – Ocular redness – allergy to meds, CL 27

  28. Canal-based, non disruptive MIGS Procedures  Dilates and preserves Schlemm’s canal by channel reconstruction and trabecular meshwork bypass  Re-establish flow to collector channel system  May be performed with or without cataract surgery  Options: 1. iStent (Glaukos) 2. Hydrus (Ivantis)

  29. Glaukos iStent

  30. Prevalence of Glaucoma and Cataract Of the 3.5 million annual cataract procedures performed in the US, 20.5% *of these patients are on a glaucoma medication 20.5% 79.5% 20.5% A Large Percentage of your Patient Population fits the Approved Indication Patients with Cataract Patients with Cataract and Glaucoma/OHT * Medicare data analysis 2003 - 2007

  31. Effect of Cataract Surgery on IOP Reduction Baseline IOP (mm Hg) 18-19 n=86 20-22 n=62 15-17 n=223 9-14 n=198 23-31 n=19 87% of patients who underwent cataract extraction experienced minimal to no reduction in IOP 0.2 1.6 • 53% had a mean reduction of 1.6 to 2.5 mm Hg • 34% had an increase of 0.2 mm Hg 2.5 IOP (mm Hg) 4.7 6.5 From a retrospective chart review of 588 normotensive and OHT patients who underwent cataract surgery Poley BJ, Lindstrom RL, et al. Long-term effects of phacoemulsification with intraocular lens implantation in normotensive and ocular hypertensive eyes. J Cataract Refract Surg .2008;34(5):735-42. 31

  32. When Should iStent Be Used?  In any patient with mild-moderate glaucoma undergoing cataract surgery – Patients on 1 glaucoma med –Goal: getting patient off meds – Patients with normal VF

  33. What is Mild to Moderate OAG? 1. American Academy of Ophthalmology Glaucoma Panel. Preferred Practice Pattern. Primary Open-Angle Glaucoma Report 2010

  34. When Should iStent Be Used?  In any patient with mild-moderate glaucoma undergoing cataract surgery – Patients on 1 glaucoma med –Goal: getting patient off meds – Patients with normal VF  iStent: Option to treat glaucoma as a surgical disease

  35. Gonioscopy is back!  Get comfortable in the office with gonioprism – Seldom done yet billable – Gonioscopy.org – great source  Practice before a scheduled case – Use a gonioprism in one hand and Sinsky hook in the other 35

  36. Gonio Imaging - Angle Structures Normal angle - inferior view 36

  37. Gonio Imaging - Angle Structures 37

  38. RG: Case Study  79 y/o woman referred for glaucoma  History: – RK + LASIK OD, RK OS – Blepharospasm (on Botox) – Dry eye – Ocular allergies (to BAK and other preservatives) – Cataract  Meds: Non-preserved Timolol qd OU 38

  39. RG: Case Study 39

  40. RG: Case Study  Exam: OD OS – Acuity +1.75+2.50x045=20/60 0.50+1.00x128=20/80 – SLE RK scars OU, 2+ NS – IOP 14 15 – Fields Unreliable OU – Disc 0.8 cup 0.8 cup 40

  41. RG: Case Study 41

  42. RG: Case Study 42

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  44. RG: Case Study  Underwent uncomplicated phaco/IOL (24D) with iStent  Results: – Discontinued eye drops – IOP under control – Dry eye symptoms improved – Very happy with result 44

  45. First 50 iStents: IOP IOP following iStent 25.000 19.729 N=48 18.935 N=31 20.000 17.205 N=44 Average IOP (mmHg) 15.625 N=16 14.923 N=13 15.000 10.000 5.000 0.000 Pre-Op 1 day 1 month 2 months 3-4 months 45

  46. First 50 iStents: Number of Eye Drops Number of Eye Drops after iStent 3.000 Average Number of Eye Drops 2.245 2.500 2.000 1.500 1.000 0.500 0.417 0.500 0.082 0.020 0.000 Pre-Op 1 day 1 month 2 months 3-4 months 46

  47. iStent Insertion Tips 1. Head positioning 2. High magnification of microscope 3. Maximize visibility (gonio view) 4. Viscoelastic (just the right amount) 5. Angle tip of injector into TM 6. Press forward while injecting 7. Re-assess after placement 47

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  49. Superficial iStent Placement 49

  50. Well Placed iStent 50