1. Glaucoma Drainage-Device Surgery
Pf. 박찬기/R3.염혜리

2. Open-Tube Drainage Device
Baerveldt
Molteno
Schocket
Flow-restricted Drainage Device
Ahmed
Krupin

3. Molteno Krupin Ahmed 1973 1976 1981 1992 1993 Baerveldt
Double plate Molteno
Molteno
Krupin
Baerveldt
Ahmed
1973
1976
1981
1992
1993

4. Baerveldt Implant
In 1992
Non valved silicone tube + soft barium-impregnated silicone plate (surface area: 250mm2, 350mm2)
Fenestration: allow growth of fibrous tissue, reduce height of bleb -> reduce the risk of diplopia & help to secure
Under rectus m. at superotemporal Q

5. Baerveldt Implant Indication NVG PPKP c glaucoma
RD surgery with glaucoma
ICE synd.
Traumatic glaucoma
Uveitic glaucoma
Previous failed trabeculectomy
Epithelial downgrowth
Refractory infantile glaucoma

6. Fibrous capsule : post op. 3~6wks IOP<21mmHg : 87%(350mm2)
Success rate : 79 %(350mm2) at 5 yrs
350mm2 implant similar to double plate Molteno & Ahmed valve lowering IOP FU 1yr & 4yrs
-Syed et al. and Tasi et al.
similar to trabeculectomy with MMC for IOP control and avoiding hypotony & reoperation FU 1 yr Gedde et al.

7. Molteno Implant In 1973 : prototype device
Polypropylene plate + silicone tube
Single plate(137mm2) : outer circular ridge containing a triangular pressure ridge
In 1981, Double plate Molteno implant : increase surface area(274mm2): success rate 25~46% -> 40~71%,
Molteno 3: single plate (175mm2, 230mm2), thinner & more flexible plate and elliptical pressure ridge, limiting the available area of filtration during low aqeous production

8. Molteno Implant Indication Infantile and juvenile glaucoma
Aphakic or pseudophakic glaucoma
Traumatic glaucoma
Uveitic glaucoma
Glaucoma secondary to previous intraocular surgery
Neovascular glaucoma
Failed previous trabeculectomy
Complications of trabeculectomy on fellow eye

9. Outcome
Baerveldt versus double-plate Molteno :similar reduction in IOP (greater than 44%), success rates, and visual outcomes with almost 1 year of follow-up Smith et al.
Ahmed versus double-plate Molteno: Molteno produced a statistically significant lower IOP at 12 and 18 and lower risk of developing a hypertensive phase(43.5%) compared with the Ahmed(83.5%). ultimate success rates that were similar (approximately 50%) at 24 months. -Ayyala RS et al.

10. Schocket tube shunt
360-degree silicone band(reservoir for aqeuous drainage)+silicone or silastic tube
Modification: 90 degree beneath 2 rectus m.
Schocket tube vs double plate Molteno
: lower final IOP-double plate Molteno

11. Open tube drainage
Cx. ) hypotony, flat anterior chambers, and choroidal effusions
To prevent hypotony d/t lack of outflow resistance
ligate the tube with dissolvable suture: dissolve in 6-8wks(fibrous capsule formed around the plate providing some resistance)
thread a suture into the tube to obstruct
implant 2 stage: 1) end plate implant
2) tube implant after forming the capsule

12. Krupin Implants produced in 1976 oval silastic disc(13mm x 18mm)+tube
pressure sensitive unidirectional valve to provide
resistance to outflow and prevent post op.hypotony
Valve effect: making slits in the closed ext. end of the tube open at IOP 11mmHg & close at IOP 9mmHg
113 eyes: transient post op.hypotony-3 eyes
chronic hypotony-1 eye

13. Other

14. Ex-PRESS Ex-PRESS glaucoma drainage divice
3mm long stainless steel tube without external plate
excellent biocompatibility
implant under a traditional trabeculectomy flap or scleral flap
IOP 27.2±7.1mmHg ->14.5±5.0mmHg over 12months -Dahan et al.

15. Solx Gold Shunt
Solx Gold Shunt: 3x6mm sized 24K gold that connect the AC & suprachoroidal space-> no subconj.drainage(no bleb)

16. iStent iStent trabecular microbypass stent stainless steel stent
Undergoing cataract surgery
delivered ab interno through a clear corneal incision, advanced through the trabecular meshwork and implanted into Schlemm canal for aqueous humor to drain directly from the anterior chamber into Schlemm canal
avoids any manipulation of the iris, conjunctiva, or sclera

17. Outcome
No statistical difference according to the surface area of plate
Maximum end-plate area to achieve IOL lowering with additional surface area

18. Outcome
The success rates : about 70% of mean IOP lowering at least 50% from the pre op (all)
The failure rates : about 10% per year, leading to only 50% functional drainage devices at 5 years.

19. Long term outcomes More than 12 months
Success: low end cutoff- 5~6mmHg, high-end cutoff-21~22mmHg c/s medication
Molteno:
73~74 %(18mo), 57%(43~44mo)
76% in uveitic glaucoma(5~10yrs)
72% in black patients(30mo)
Double plate> single plate
Failure: m/c in 1st post operative yr
Failure increase in pseudophakia & NVG

20. Schocket-type drainage device Baerveldt implants
91%(10mo), 81%(17.5mo), 30%(36mo)
Baerveldt implants
93%(350mm2)(18mo)
71%(2yr)
Krupin eye valve & disc
84%(6mo)m 66%(12mo)
80%(25mo)
Ahmed drainage device
77~87%(1yr), 75%(2yr)

21. Complications Early postoperative hypotony Diplopia Tube extrusion
No valve mechanism
Ahmed valve:8~13%, Krupin valve: 8%
Diplopia
Highest with the Baerveldt implant(3~18%)
(large size & shape, ins.underneath the rectus m.->direct disturbance, scar formation, height of the bleb)
Tube extrusion
infection

22. Causes of Failure Bleb encapsulation(early), fibrosis(later)
Two stage of bleb
Hypotensive phase: 1st lasting 1-4wks
diffuse edema, congestion of blood vessel in the tissue covering the episcleral plate of implant
Hypertensive phase: >21mmHg, begins 3-6wks, last for months, definite layer of fibrous tissue at deepest layer of bleb capsule
Hypothesis
Glaucomatous aqeuous lead to fibroproliferation

23. GDD as Drug Delivery System
end-plate: reservoir for drug
Tube: instead of draining aqeous, deliver drug from end-plate into the eye via one-way pressure-dependent valve
External pr.>cracking pr. of one way valve
Limitation
Mark Humanyan: wireless programming system (accuracy rate of±2%)