Moran CORE

Glaucoma Ahmed Tube Shunt

Home / Ophthalmic Surgery / Glaucoma Surgery

Title: Glaucoma Ahmed Tube Shunt
Author (s): Russell Swan, MD; Craig Chaya, MD
Date: 7/18/2016
Keywords/Main Subjects: Glaucoma; Tube Shunt
Secondary CORE Category: Glaucoma / Surgical Therapy for Glaucoma
Diagnosis: Glaucoma; POAG
Brief Description: This video demonstrates a standard surgical technique for Ahmed tube shunt at the University of Utah Moran Eye Center with Dr. Craig Chaya. Below is our standard protocol:

1. Mark the superior and temporal conjunctiva
2. Perform conjunctival dissection and ensure carried to bare sclera. Relaxing incisions should be made at 12 and 3 oclock (left eye) and 12 and 9 oclock (right eye)
3. Blunt dissection into superior temporal subconjunctival space to create space for placement of shunt
4. May use brimonidine soaked sponge for additional hemostasis
5. Isolate lateral and superior rectus muscles and mark insertions
6. Prime valve using 27 gauge cannula and tying forceps
7. Deliver Ahmed plate into the superior temporal sub-Tenons space
8. Mark sclera 7.0mm posterior to the limbus
9. Pass 7-0 vicryl suture partial thickness through eyelet holes at anterior edge of place of tube
10. Tie off tube with 7-0 vicryl suture (double loop so that the tube is not amputated)
11. Ensure no flow through the tube
12. Create wick suture through tube with 7-0 vicryl suture
13. Create fenestration in tube anterior to wick suture. These two will help with IOP control in the immediate post op time period.
14. Measure position of tube and cut bevel up with scissors
15. Bend 23 gauge needle to use for entering the anterior chamber
16. Mark 3.0mm posterior to the limbus in the location you wish the tube to enter (preferably superior)
17. Create temporal paracentesis to have access to reform AC as needed
18. Initiate partial thickness scleral tunnel with 23 gauge needle and rotate eye into neutral position. Try to enter the ac just anterior to the iris root so that the tube will not be against the cornea
19. Flare scleral tunnel edge upon exit to make passage of tube easier
20. Pass tube into scleral tunnel and into AC
21. Use 7-0 vicryl suture to secure tube location with ‘X’ stitch
22. Measure patch graft material and cut to size
23. Secure anterior edge of patch graft with 7-0 vicryl suture
24. Mobilize conjunctiva and Tenon’s over the tube and plate
25. Close conjunctiva:
    1. Start with buried horizontal matress suture. Ensure episcleral bite to help prevent flap from slipping.
    2. Cut short end of suture and then use a running suture to close the relaxing incision
    3. Close the second relaxing incision in a similar fashion
    4. This can be done with the same 7-0 vicryl suture or a 10-0 vicryl suture

Tube Shunt Post-Op Guidelines

Drops:

• Continue aqueous suppressants to keep IOP as low as possible in order to blunt hypertensive phase. If IOP below 10mmHg then OK to stop them until IOP rises.
• Avoid prostaglandins after tube surgery (can increase inflammation around plate and promote encapsulation)
• Use Pred q2hrs while awake for the first 2-3 weeks then begin tapering. Taper off steroids after 6-7 weeks. Prolonged use may paradoxically promote more encapsulation and cause steroid response
• Okay to use topical and oral NSAIDs if additional inflammatory control needed
• Okay to use short course of oral Prednisone (Medrol dose pack) to help with inflammatory control in certain patients
• Antibiotic QID for 7 days and then stop

Visits:

• Recheck POD#1, POW#1, and every 2 weeks until 2 months post-op assuming all is stable
• Make sure pt returns for a visit when ligature opens up (~6 weeks post-op) to see how low IOP is and make sure chamber has not shallowed too much

Misc:

• Okay to use oral NSAIDs to control hypertensive phases
• Consider tapping blebs over plate to reduce hypertensive phase
• Tube will NOT be fully flowing until ligature suture dissolves around 6 weeks post-op
  • Fenestrated tube in front of the ligature suture will provide early filtration and IOP control

Format: video
Faculty Approval by: Craig Chaya, MD
Identifier: Moran_CORE_21536
Copyright statement: Russell Swan, MD, ©2016. For further information regarding the rights to this collection, please visit: http://morancore.utah.edu/terms-of-use/
Attribution/citation suggestions:
Swan, R and Chaya, C. Glaucoma Ahmed Tube Shunt. Moran CORE. Available at: http://morancore.utah.edu/section-14-ophthalmic-surgery/glaucoma-ahmed-tube-shunt/. Accessed July 27, 2016.

Phaco-Trabeculectomy

Home / Ophthalmic Surgery / Glaucoma Surgery

Title: Phaco-Trabeculectomy
Author (s): Russell Swan, MD; Craig Chaya, MD
Date: 7.18.2016
Keywords/Main Subjects: Glaucoma, Trabeculectomy, Trab, Cataract, Phacoemulsification, Phaco
Secondary CORE Category: Home / Glaucoma / Surgical Therapy for Glaucoma
Diagnosis: Glaucoma, Primary open-angle glaucoma (POAG), Cataract
Brief Description: This video demonstrates a standard surgical technique for phaco-trabeculectomy at the University of Utah Moran Eye Center with Dr. Craig Chaya. Below is our standard protocol for the trabeculectomy portion of the surgery. Of note the cataract surgery is still performed with a standard temporal clear corneal incision which is closed with a 10-0 nylon suture at the end of the cataract portion of the surgery. The microscope is then rotated superiorly for the trabeculectomy portion of the surgery:

1. Place 7-0 Vicryl traction suture partial thickness in superior cornea to provide infraduction
2. Inject subconjunctival lidocaine superior and displace across superior conjunctival bed
3. Place corneal light shield soaked in BSS
4. Inject subconjunctival Mitomycin C (0.2ml of 0.2mg/ml) superiorly
5. Displace across superior conjunctival bed while blocking limbus with surgical sponge
6. Superior conjunctival peritomy leaving 1-2mm limbal skirt for improved closure
7. Ensure underlying Tenon’s is free.
8. Blunt dissection in the superior sub Tenons space
9. Cautery to scleral bed where flap will be located
10. Measure 3.0mm posterior to the limbus for dimensions of scleral flap
11. Initiate posterior edge of scleral flap at ~50% depth (may use guarded diamond blade or scleratome blade
12. Carry scleral flap dissection anterior into the cornea trying not to enter the AC at this time
13. Create medial and lateral edges of scleral flap
14. Ensure flap is free of adhesions
15. Pre-place 2 10-0 nylon sutures at corners of scleral flap. These should actually be about 2/3 the distance posterior along the flap so that they will promote posterior flow through flap
16. Ensure adequate pressurization of the AC. May consider using small amount of dispersive OVD in the angle to maintain AC upon entrance
17. Use keratome to enter AC. Ensure that you do not cut your 10-0 sutures
18. Use Kelly punch to remove cornea tissue. Pass punch into AC and catch posterior lip of tunnel. Once posterior lip is engaged then rotate instrument and hand vertical before engaging punch.
19. Use sliding knot to tighten sutures. Tie 1-1 first and check for no/minimal passive flow through the flap.
20. Pressure on the posterior edge of the flap with a surgical sponge should provide flow
21. If adequate flow then tie of suture (total 1-1-1), cut short, and rotate the knot
22. Begin conjunctival closure with 10-0 vicryl suture. This is a critical step to reduce risk of post op hypotony after surgery.
23. Start with buried suture at far corner of peritomy
24. Continue with modified Wise closure¹. Please refer to Figure below for closure tips
25. To end closure there will be two buried episcleral bits that emerge and re-enter near the limbus. Using loop of suture from this and free end of suture the closure is tightened, tied and cut short. NOTE: In figure the green loop at the limbus is tied to the free end of suture to finish the closure.

Trab Post-op Guidelines

Drops:

• Prednisolone 1%: q2 hrs while awake for the first 3-4 weeks and then a slow taper over 3 months (QID for 2 weeks, TID for 2 weeks, BID for 2 weeks, Qday for 2 weeks then stop)
• For those more likely to scar may elect for Druezol QID for 1 month and then TID for 2 weeks BID for 2 weeks Qday for two weeks
• Antibiotics QID for 1 week and then stop
• NSAIDS only if phaco/trab
• Stop all glaucoma drops at time of surgery to promote flow through the flap and reduce risk of scarring. But OK to restart if IOP not controlled despite best efforts and promoting flow through bleb
• Avoid prostaglandins after surgery (can increase inflammation around bleb). Ok to restart if bleb failed
• Consider early needle bleb revision (within 3 months of original surgery) to try and revive bleb

Visits:

• Recheck POD#1 and then weekly for 4-6 weeks

Misc:

• Wound Leak: if there is a small conjunctival wound leak then stop NSAID, stop steroid, consider aqueous suppressant and consider large diameter BCTL use until leak resolved. OK to restart steroid/NSAIDS and stop aqueous suppressants after leak healed
• If the AC is moderately shallow may consider cycloplegia to rotate the ciliary body posteriorly and deepen the chamber
• Carlo Traverso Maneuver: Used for opening scleral flap in the early post-operative period with elevated IOP.
  • Have the patient look down while pressing firmly on the upper eyelid posterior to the scleral flap in an attempt to open the trap door.
  • If this does not work you can also have the patient look up and press inferiorly. You hope to see increase in the bleb size indicating improved flow.
  • This second technique can be taught to the patient for them to do at home in the setting of a failing bleb (stress to use the broad base of your finger and press firmly.)
• Suture Lysis:
  • Ok to perform as early as 1 week depending on response to digital pressure.
  • Cut suture away from the scleral flap to decrease risk of scarring
  • Check response to suture lysis immediately and if you need to cut another suture the same day you can
• 5-FU: Consider 5-FU for trabs at high risk of failure (0.1ml of 50mg/ml concentration = 5mg)
  • At the VA you have to request this as an inpatient non-formulary request and have the pharmacy deliver it to clinic (or send someone down to get it)
  • Do NOT inject over the scleral flap or in the bleb. Instead inject adjacent to (or even 180 degrees away from the bleb)
  • Use 30 gauge needle bevel down and slide just under the conjunctiva. If some 5-FU leaks out then use q tip to reduce more leakage and rinse cornea to reduce risk of epithelial breakdown
  • Repeat up to 3 times with 2-3 days between each injection
• Needle Revision: Often reserved for after aggressive PF, suture lysis and 5-FU fail, but these steps should all occur quickly so that needling can occur at within 3 months of original trab.
  • Can be done at the slit lamp but most likely will be taken to the OR.
  • Use 30 gauge needle essentially as a crow bar to break adhesions and lift the scleral flap and reform the bleb.

Format: Video
Faculty Approval by: Craig Chaya, MD
Identifier: Moran_CORE_21527
Copyright statement: Russell Swan, MD, ©2016. For further information regarding the rights to this collection, please visit: http://morancore.utah.edu/terms-of-use/
Attribution/citation suggestions:
Swan, R and Chaya, C. Phaco-Trabeculectomy . Moran CORE. Available at: http://morancore.utah.edu/section-14-ophthalmic-surgery/phaco-trabeculectomy/. Accessed July 27, 2016.