Study: T.Flux glaucoma implant effectively reduces IOP

The non-absorbable implant, available in Europe, showed significant ability to reduce IOP when used in conjunction with non-penetrating glaucoma surgery.

LA ROCHELLE, France — The T.Flux non-absorbable hydrophilic glaucoma implant enables superior filtration for glaucoma patients, according to results of a 3-year study. After positioning in a deep sclerectomy, the T.Flux implant, from IOLTech Laboratories, located here, creates an evacuating canal along the foot of its structure, which helps to form a permanent intrascleral space.

The implant stabilizes the trabeculo-Descemetic membrane and prevents adhesions between the scleral flap and the trabecular meshwork. It also stimulates the formation of new aqueous veins for and efficient evacuation of aqueous humor surplus.

According to the study, the T.Flux implant effectively reduced postoperative intraocular pressure (IOP) for a prolonged period of time.

T.Flux materials

The T.Flux implant is the first non-absorbable glaucoma drain implant, according to the manufacturers. It derives its name from its “T” shape and is made of poly-MEGMA, a highly hydrophilic acrylic. The shape and material help to drain fluid by means of capillarity and osmosis.

The T.Flux is designed for use with non-penetrating glaucoma surgery (NPGS). NPGS is a technique, often employing one of a number of space-creating drainage implants, designed to reduce IOP in open-angle glaucoma.

Implant study/procedure

The 3-year trial was conducted at the Glaucoma Centre, Hôpital Ophthalmique Jules Gonin in Lausanne, Switzerland, under the supervision of Andre Mermoud, MD, and at the Unit Against Glaucoma in Johannesburg, South Africa, under the supervision of Elie Dahan, MD. The results from Dr. Mermoud and Dr. Dahan’s study are from 54 eyes of 38 patients followed from July 1997 to July 2000.

NPGS was performed on all 54 eyes. The T.Flux was implanted in 27 eyes; 27 eyes served as control. All eyes studied had comparable severity of glaucoma.

The technique for NPGS with T.Flux implantation begins with a fornix-based conjunctival flap. A trapezoidal superficial scleral flap, 5 mm by 5 mm by 1.5 mm, is made at 40% depth. The superficial scleral flap is dissected into the clear cornea and reflected back with a temporary 8-0 virgin silk suture anchored in the limbus at 6 o’clock. A trapezoidal deep sclerectomy, 3.5 mm by 3.5 mm by 1.3 mm, is performed to 90% depth within the scleral bed.

The deep scleral flap is reflected back, unveiling the scleral spur, the trabecular meshwork and Descemet’s membrane. The trabecular meshwork can be “reconditioned” by scraping and peeling in order to improve filtration. The T.Flux glaucoma implant is positioned within the deep sclerectomy, with its flat surface facing the trabeculo-Descemetic membrane and its arms tucked into Schlemm’s canal.

The T.Flux is then loosely sutured in place without excessive tension with a 10/0 nylon suture. The superficial scleral flap is reflected back into the deep sclerectomy to cover the T.Flux and is secured in place with one 10/0 nylon suture at its apex. The conjunctiva is sutured back into place with one limbal 10/0 buried nylon suture. The scleral flap and the conjunctiva do not need to be watertight because of the non-penetrating nature of this filtration procedure, the surgeons said.

Reduction in IOP

The study showed that the T.Flux group’s IOP dropped from a mean of 26.7 mm Hg preoperatively to a mean of 11.2 mm Hg postoperatively. In the non-implanted group the IOP dropped from a mean of 25.5 mm Hg preoperatively to a mean of 15.5 mm Hg postoperatively.

In the non-implanted group, four revisions of the filtration site were performed in order to keep IOP below 20 mm Hg without resorting to medications. None of the T.Flux eyes needed such revisions during the 3-year follow-up.

The T.Flux works because it creates a permanent draining space under the superficial flap, according to the manufacturer. Its arms lie on the trabeculo-Descemetic membrane, stabilizing it and preventing iris herniations, in case YAG micro-punctures become necessary.

Drs. Dahan and Mermoud concluded that the T.Flux with NPGS improved IOP lowering, both in magnitude and in longevity. Because the implant is made of a highly hydrophilic acrylic, it has proven to be non-absorbable and biocompatible.

A note from the editors:

The T.Flux implant is currently not available in the United States.

T.Flux’s “T” design allows active draining by means of capillarity and osmosis.	A fornix-based conjunctival flap is performed to begin the implantation.
Trapezoidal superficial scleral flap is created at 40% depth.	The superficial scleral flap is dissected into clear cornea and reflected back with a temporary 8-0 virgin silk suture anchored in the limbus at 6 o’clock. A trapezoidal deep sclerectomy at 90% depth is performed within the scleral bed.
The deep scleral flap is reflected back, revealing the scleral spur, the trabecular meshwork and Descemet’s membrane. The T.Flux is positioned within the deep sclerectomy. The flat surface faces the trabeculo-Descemetic membrane, and the arms are tucked into Schlemm’s canal.	The superficial scleral flap is reflected back into the deep sclerectomy onto the T.Flux and is secured in place with one 10-0 nylon suture at its apex. The conjunctiva is sutured back into place with one limbal 10-0 nylon (buried). Neither the scleral flap nor the conjunctiva need to be watertight because of the non-penetrating nature of the filtration procedure.
The T.Flux is loosely sutured in place without excessive tension using a 10-0 nylon suture. Its arms extend into Schlemm’s canal, keeping the drainage channel open.
The T.Flux is the first non-absorbable glaucoma drain. It derives its name from its “T” shape and is made of poly-megma, a highly hydrophilic acrylic. The shape and material help to drain fluid by means of capillarity and osmosis.

For Your Information:

• Elie Dahan, MD, can be reached at Oxford Eye Centre, 104 Oxford Rd., 2198 Johannesburg, South Africa; (27) 11-880-4200; fax: (27) 11-880-3610; e-mail: dahaneli@cis.co.za. Dr. Dahan has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.
• Andre Mermoud, MD, can be reached at Hôpital Ophthalmique Jules Gonin, Avenue de France 15, Lausanne, CH-1004, Switzerland; (41) 21 626 8586; fax: (41) 21 626 8246; e-mail: andre.mermoud@ophtal.vd.ch. Dr. Mermoud has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

• IOLTech Laboratories, makers of the T.Flux implant, can be reached at Av. Paul Langevin, BP 5 17053 La Rochelle Cedex 9, France; (33) 05-46-44-85-50; fax: (33) 05-46-44-0805; Web site: www.ioltech.com.