What is an Ex-PRESS® Shunt Procedure?
The Ex-PRESS Shunt procedure implants a stainless steel device (Ex-PRESS® Glaucoma Filtration Device) under a scleral flap to allow for drainage of aqueous humor in order to relieve intraocular pressure due to glaucoma.
The Ex-PRESS® procedure is very similar to a trabeculectomy, in that a fluid path is created from the anterior chamber (inside of the eye) to the outside of the eye. The perceived value in the Ex-PRESS Shunt is that it creates a uniform and consistent sized channel for aqueous outflow into the intrascleral space. Like a trabeculectomy, the surgeon creates a scleral flap, then uses a 25-gauge needle to create a tunnel into the anterior chamber. The Ex-PRESS shunt is then implanted into the opening with a footplate flush to the surface of the sclera. The flap is brought down and sutured appropriately to regulate aqueous outflow.
Similar to a trabeculectomy, the surgeon may use mitomycin-c to suppress scarring that might disrupt fluid outflow. The procedure takes approximately 45-60 minutes. After the procedure, follow-up appointments will be scheduled to ensure intraocular pressure is at the optimal level. If needed, revisions to the flap can be made at that time. The goal of the procedure is to improve the drainage of aqueous humor out of the eye, thereby reducing excessive pressure compressing the optic nerve and causing vision loss.
Ex-PRESS Shunt Surgery Recovery
Patients with Ex-PRESS Shunt implants can expect a faster recovery than those with more invasive procedures like iridectomy of sclerectomy, according to a popular study² of trabeculectomy procedures done by Maris P, et al. Maris also found a decrease in rates of hypotony due to the promotion of controlled drainage with the Ex-PRESS shunt. Another study¹ highlighted a significant reduction in the risk of:
- Pigment release
- Bleeding from the iris
- Vitreous prolapse
All of which resulted in fewer post-surgery visits due to complications.
Benefits of Ex-Press Shunt Implantation
The following table is a short-term comparison between the Ex-PRESS Glaucoma Filtration Device vs a traditional trabeculectomy.
|Effective IOP lowering²||✔||✔|
|Maintained ocular pressure²||✔|
|Minimal inflammation and scarring³||✔|
|Less hypotony and choroidal effusion²||✔|
|Can be combined with cataract surgery||✔||✔|
|Fewer post-op visits¹||✔|
|Faster visual recovery¹||✔|
|One-year success rate∗||80%||51%|
1. Good TJ, Kahook MY. Assessment of bleb morphologic features and postoperative outcomes after EX-PRESS® drainage device implantation versus trabeculectomy. Am J Ophthalmol. 2011 Mar;151(3):507-13.e1.
2. Maris P, et al. Comparison of trabeculectomy with EX-PRESS miniature glaucoma device implanted under the scleral flap. J Glaucoma. Jan 2007;16(1):14-19.
3. Nyska A, et al. Biocompatibility of the EX-PRESS miniature glaucoma drainage implant. J Glaucoma. 2003;12(3):275-280.
* de Jong L, Lafuma A, Aguadé AS, Berdeaux G. Five-year extension of a clinical trial comparing the EX-PRESS glaucoma filtration device and trabeculectomy in primary open-angle glaucoma. Clin Ophthalmol. 2011;5:527-533.
WMI-036 Rev 01/2018