glaucoma drainage device its pros and cons meachnisiom of action and surgery video.pptx

Minimally Invasive Glaucoma Surgery (MIGS) refers to a group of modern surgical procedures that aim to reduce intraocular pressure (IOP) in glaucoma patients with less risk and quicker recovery than traditional glaucoma surgeries like trabeculectomy.​

Key Features of MIGS:
Minimally invasive: Performed through small incisions inside the eye (ab interno), minimizing tissue disruption.​

Safer profile: Compared to traditional surgeries, MIGS has a much lower risk of serious complications such as infection, scarring, or hypotony.​

Faster recovery: Patients typically recover faster and can resume daily activities sooner.​

Moderate efficacy: Provides meaningful lowering of intraocular pressure, usually at least 20%, suitable especially for mild to moderate open-angle glaucoma.​

How MIGS Works:
The procedures improve the drainage of aqueous humor (fluid inside the eye) to reduce eye pressure by:

Bypassing or removing resistance in the trabecular meshwork (natural drainage canal).​

Creating shunts to enhance fluid outflow through various anatomical pathways like Schlemm’s canal or suprachoroidal space.​

Devices used include microstents like the iStent, Hydrus Microstent, and microshunts like Xen or PreserFlo.​

Clinical Use:
MIGS is often combined with cataract surgery to treat patients who have both glaucoma and visually significant cataracts.​

It is typically recommended for patients with mild-to-moderate glaucoma who need better IOP control with fewer medications and lower risk compared to traditional surgery.​

Summary:
MIGS represents a safer, less invasive option for glaucoma surgery with faster recovery but generally less reduction in eye pressure compared to classic glaucoma surgeries. It is well suited for early to moderate glaucoma stages and reducing dependency on glaucoma medications.​

If more detailed or specific MIGS options are needed, an ophthalmologist specialized in glaucoma surgery can tailor the approach based on the patient's clinical status.

Related
Compare MIGS versus trabeculectomy for mild glaucoma
Which MIGS devices are approved and how they work
Expected recovery and side effects after MIGS surgery
MIGS outcomes when performed with cataract surgery
How to choose a surgeon experienced in MIGS

1. DRAINAGE DEVICES & RECENT ADVANCES IN GLAUCOMA MODERATOR : DR. SAMYAKTA S ASSISTANT PROFESSOR DEPT. OPHTHALMOLOGY, JNMC PRESENTOR: DR. NANDISH LUKHI 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 1

2. Function by creating an alternate pathway for aqueous outflow Direct the aqueous humor towards the subconjunctival space or suprachoroidal space. where it is absorbed into systemic circulation by diffusion and through scleral veins. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 2 Principle

3. 09-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 3

4. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 4

5. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 5

6. Indications : One or more filtering procedures that have failed Refractory infantile glaucoma Neovascular glaucoma Traumatic glaucoma Uveitic glaucoma Glaucoma in aphakia or pseudophakia Glaucoma following corneal transplantation Glaucoma with Penetrating keratoplasty Glaucoma with Retinal detachment surgery Glaucoma and aniridia Glaucoma and Sturge-Weber syndrome Glaucoma and ICE syndrome Glaucoma and contact lens dependence Glaucoma and epithelial ingrowth Glaucoma and severe surface disease (chemical burns, pemphigoid) 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 6

7. Contraindications: Eyes with severe scleral or sclera-limbal thinning Extensive fibrosis of conjunctiva Ciliary block glaucoma. Relative Contraindications: Vitreous in AC Intra-ocular silicone oil-Implant if required is placed in infero temporal quadrant 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 7

8. PHYSIOLOGY OF DRAINAGE IMPLANTS Basic design : The large plate surface promotes posterior bleb formation near the equator. The ridge on the plate guides the tube and prevents posterior obstruction by fibrous tissue. A silicone tube extends from the anterior chamber or vitreous cavity to a plate beneath the conjunctiva and Tenon capsule. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 8

9. After insertion, collagenous capsule forms around it Surrounded by a granulomatous reaction Reaction resolves in 4 months Capsule remains stable Matures over time, becomes thinner after 6 months Filtering bleb 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 9 IOP control depends on the fibrous capsule forming a filtering bleb around the implant. The plate’s surface area determines the rate of aqueous outflow and pressure control.

10. Most glaucoma drainage devices show a rise in IOP weeks to months after surgery due to capsule formation around the implant plate — called the hypertensive phase . Bleb failure occurs when a thick fibrous capsule forms around the drainage implant. Implant movement against the sclera may trigger mild wound healing, leading to more collagen deposition, scarring, and capsule thickening — causing implant failure. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 10

11. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 11 Non resistant glaucoma drainage devices

12. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 12

13. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 13 Moved to a position a few millimetres away from limbus to allow for better drainage. has two connected plates (one linked to the anterior chamber tube) providing a larger surface area. Offers better IOP control but carries a higher risk of hypotony single-plate implant, in which a V-shaped “pressure ridge” is present on the upper surface of the plate In view to combat hypotony from over-filtration. Has a bowl-shaped area near the tube opening that acts as a biologic valve , reducing aqueous flow when production is low.

14. 2 . Baerveldt implant A silicone tube attached to a barium-impregnated plate. Fenestrations allow fibrous tissue growth through the plate, lowering bleb height , reducing diplopia , and stabilizing the implant . 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 14

15. The plate is placed under the rectus muscles, usually in the superotemporal quadrant. Within 3–6 weeks, a fibrous capsule forms around it, allowing aqueous drainage and absorption by nearby tissues. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 15

16. 3.Schocket Tube Shunt Anterior Chamber Tube Shunt To Encircling Band ( ACTSEB ) A silicone tube runs from the anterior chamber to a 360° encircling silicone band, which acts as a reservoir for aqueous drainage. Modifications: Tube inserted into a 90° band placed under two rectus muscles Tube connected to a preexisting encircling band in eyes with glaucoma after scleral buckle surgery. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 16

17. Miniature non-valved device with no external plate Made of rigid stainless steel (like cardiac stents) Less than 3 mm long and biocompatible Forms a small potential space and fibrous capsule to regulate outflow Implanted under a trabeculectomy flap 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 17 4.Ex-PRESS Shunt

18. 5.Glaukos istent A lightweight, L-shaped titanium device placed in Schlemm’s canal. Heparin coating makes it biocompatible, provides thrombolytic action, and prevents stenosis. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 18

19. Most commonly used valved implant Design: Silicone tube attached to a silicone-sheathed valve in a polypropylene body 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 19 B)Valved/Flow Restrictive implants:  1.Ahmed Glaucoma Valve (AGV) Ahmed valve – Three-piece design: F: Silicone elastomer foils – control one-way aqueous flow . TC: Tapered chamber – creates Venturi flow toward the valve body. B: Valve body – houses the flow-regulating mechanism. E: Fixating eyelets – anchor the implant to the sclera. AB: Assembly bolts – adjust foil tension for proper flow control .

20. Priming: Ahmed’s valve must be primed before use. A 27-gauge cannula is inserted 2 to 3 mm into the tube and BSS is injected until it separates the elastomer foils often a small “popping” sound is heard while the BSS separates the silicone foils. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 20

21. Material Surface Area Type Silicon FP7 84mm² Single valve plate FP8 96 mm² Small valve plate FX1 180mm² 2 plates Polymethylmethacrylate Polypropylene S2 184mm² Single valve plate S3 96 mm² Small valve plate B1 180mm² 2 plates 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 21

22. “ No-touch zone ”: The area over the valve chamber containing the silicone leaflets. Grasping this area with forceps can separate the valve cover, causing: Valve leak → early postoperative hypotony Fibrovascular ingrowth between leaflets Valve failure due to membrane adhesion. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 22

23. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 23

24. Made of an internal Supramid tube inside an external silastic tube. Valve mechanism: small slits at the closed end opened when IOP was 9–11 mm Hg. Failure causes: Short tube (only a few mm subconjunctival). No external plate → limited drainage area. Fibrosis closed the subconjunctival portion, leading to valve failure. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 24 2.Krupin Implant

25.   Gold micro-shunt DeepLight glaucoma system: combines a titanium-sapphire laser with a photo-titratable gold microshunt . The laser delivers microsecond infrared pulses that open the trabecular meshwork, improving aqueous outflow. The gold shunt is biocompatible, made of 99.5% pure gold, and is a flat plate (5.2 × 2 × 0.06 mm) with multiple microchannels for fluid drainage. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 25 2.GDD with variable resistance:

26. Surgical Preparation • Traction Suture : 6-0 Vicryl or silk suture near superior limbus to rotate globe. • Conjunctival Flap : Fornix-based conjunctival-Tenon flap in superotemporal quadrant; blunt dissection between Tenon and episclera . • Isolation of Recti : Isolate two rectus muscles with muscle hook for exposure. Glaucoma Drainage Device Surgery

27. Implant Placement • Implant Placement : Plate positioned 8–10 mm behind limbus under Tenon’s and secured with 9-0 Prolene/nylon. • Tube Preparation : Tube cut bevel-up (2–3 mm into AC); limbal area cauterized to prevent bleeding. • Anterior Chamber Entry : 23- or 22-gauge needle passed parallel to iris plane for watertight tract.

28. Tube Insertion & Closure • Tube Insertion : Tube inserted through tract and secured to sclera with nonabsorbable suture. • Patch Graft : 5×7 mm donor graft (pericardium, sclera, or fascia lata ) placed over tube to prevent erosion. • Closure : Conjunctiva sutured with Vicryl ; subconjunctival steroid and antibiotic injected away from site.

29. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 29

30. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 30 Bleeding Misdirection of silicone tube Loss of aqueous Hypotony Increased IOP Corneal decompensation Early post-op endophthalmitis Encysted bleb Erosion of silicone tube Plate migration Limitation of eye movement endophthalmitis

31. a. Bleeding Cause: Neovascular glaucoma Risk: Tube blockage B. Tube may misdirect into posterior chamber with peripheral anterior synechiae. C. Aqueous loss occurs if port > tube size. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 31 Intraoperative Complications

32. A. Hypotony : Small effusions: resolve spontaneously. Large effusions (kissing choroids): may need evacuation. Prevention: use valved implants or tube occlusion (stent/ligature). 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 32 Early Postoperative Complications

33. B. Increased IOP (Tube Occlusion): Iris blockage: treat with YAG laser ablation. Vitreous blockage (in aphakes ): prevent with complete vitrectomy before tube insertion. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 33

34. C. Corneal Decompensation: Caused by retrograde flow from the reservoir or tube–cornea touch. D. Early Postop Endophthalmitis: Rare complication; treat with immediate implant removal and infection control, then reimplant later. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 34

35. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 35

36. A. Encysted bleb. Deflate bleb to reopen compressed drainage channels. Up to 1 cm³ aqueous may be withdrawn safely. Needling is easier as blebs are relatively avascular. Medical regimen: Diclofenac 75 mg + Prednisolone 40 mg + topical steroids for ≥6 weeks, started within 14 days postop. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 36 Late Complications

37. B. Tube Erosion: Silicone tube may erode through sclera, patch graft, or conjunctiva. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 37 C. Plate Migration: Occurs if implant not securely fixed. Medial migration can cause myositis, which resolves after implant removal.

38. D. Limitation of Eye Movements: More common with upper nasal placement; mainly affects up gaze. May cause exotropia, hypertropia, or restricted rotations. Lower fornix placement can limit downgaze and cause diplopia. E. Endophthalmitis: Tube or plate exposure is the main risk factor. Requires surgical revision with patch graft to prevent infection. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 38

39. Epithelial downgrowth: may cause implant failure, corneal decompensation, or Tenon’s cyst. Epithelial invasion: leads to persistent aqueous leak. Sterile hypopyon. Irregular pupil: from iris root adhesion to tube (late complication). Globe perforation: during plate suturing → retinal detachment or vitreous haemorrhage, especially in high myopes. Retinal complications: RD, suprachoroidal haemorrhage, vitreous haemorrhage, choroidal effusion. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 39 Other possible complications

40. Success rate: 65–85% for IOP control. Molteno implants: greater IOP reduction but higher complication and resurgery rates than Ahmed. Paediatric glaucoma : lower success; >30% failures, often needing further surgery. Neovascular glaucoma: success ~62% at 1 year, but declines over time. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 40 Outcomes

41. Ref : Shields textbook of glaucoma Journal of Clinical Ophthalmology and Research - May-Aug 2013 - Volume 1 -Issue 2 Glaucoma drainage devices DOS times Feb 2008 vol .13 issue no 8 Aqueous Drainage Devices V. Velayutham MS Atlas of Glaucoma Surgery Tarek Shaarawy MD André Mermoud MD P ubmed The New Era of Glaucoma Micro-stent Surgery dec 2016vol 5 issue 2 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 41

42. 16-10-2025 DEPARTMENT OF OPHTHALMOLOGY, JNMC BELAGAVI 42 THANK YOU