Clinical results with the Trabectome, a novel surgical device for treatment of open-angle glaucoma

Abstract

Purpose: To describe treatment outcomes after Trabectome surgery in an initial series of 101 patients with open-angle glaucoma.

Methods: A 19-gauge microelectrosurgical device enabled ab interno removal of a strip of trabecular meshwork and inner wall of Schlemm's canal under gonioscopic control with continual infusion and foot-pedal control of aspiration and electrosurgery. A smooth, pointed ceramic-coated insulating footplate was inserted into Schlemm's canal to act as a guide within the canal and to protect adjacent structures from mechanical or heat injury during ablation of a 30- to 90-degree arc of angle tissue.

Results: Mean preoperative intraocular pressure (IOP) in the initial 101 patients was 27.6 +/- 7.2 mm Hg. Thirty months postoperatively, mean IOP was 16.3 +/- 3.3 mm Hg (n = 11). The mean percentage drop over the whole course of follow-up was 40%. At all times postoperatively, the absolute and percent decrease in IOP from preoperative levels were statistically significant (paired t test, P < .0001). Overall success (IOP </= 21 mm Hg with or without medications and no subsequent surgery) was 84%. Nine eyes subsequently underwent trabeculectomy, two others had IOP greater than 21 mm Hg in spite of resuming topical medications, and the rest of the patients either refused to resume medications or were still in the 1-month postoperative period without medications (total failure rate including trabeculectomies, 16/101 = 16%). Intraoperative reflux bleeding occurred in 100% of cases. Complications have been minimal and not vision-threatening.

Conclusions: The Trabectome facilitates minimally invasive and effective glaucoma surgery, which spares the conjunctiva and does not preclude subsequent standard filtering procedures.

FIGURE

Survival graph plotting “success” over time in months after Trabectome surgery. Success was defined for this illustration as a 30% or greater drop in IOP from baseline and or IOP < 21 mmHg.

FIGURE 1

Trabectome surgical tip showing infusion port of microelectrocautery unit (footplate, active straight electrode, return curving electrode).

FIGURE 2

The four major steps in Trabectome surgery for open-angle glaucoma. Top left, A clear corneal near-limbal 1.6-mm keratome incision is made. Top right, Viscoelastic may or may not be necessary to allow safe insertion of the instrument tip to allow infusion flow and anterior chamber stability. Bottom left, Surgical tip is advanced under gonioscopic control to engage nasal meshwork before activating aspiration and ablation by progressively depressing the foot pedal and rotating the tip parallel to the iris just anterior to the scleral spur. Bottom right, Ablation with continual infusion and aspiration is performed along an arc of 30° to 60° to ensure complete viscoelastic removal thereafter.

FIGURE 3

Intraocular pressure (IOP) outcomes after Trabectome surgery. Standard deviation bars and mean preoperative IOP (27.6 mm Hg at baseline) are shown. One patient from the initial series in Tijuana, Mexico, is deceased. Only 11 IOP measurements were available at 30 months postoperatively.