Implantation of a miniature glaucoma device under a scleral flap

Purpose: To test the safety and efficacy of the Ex-PRESS (TM) miniature glaucoma device when it is implanted under a scleral flap instead of under the conjunctiva as it was originally suggested. Patients and Methods: Between November 2000 and February 2003, the Ex-PRESS (TM) implant was inserted in 24 eyes of 23 patients with severe open angle glaucoma. Sixteen eyes of the 24 (66%) had had previous failed filtering surgery. The remaining 8 eyes (33%) were high risk for failures cases. A 5 X 5 mm limbal-based, 50% depth, scleral flap was raised into clear cornea. The Ex-PRESS (TM) implant was inserted into the anterior chamber under the scleral flap at the limbus. The scleral flap was securely sutured back, as is done in trabeculectomy operations. Results: The intraocular pressure was significantly reduced from 27.2 +/- 7.1 mm Hg pre-operatively to 14.5 +/- 5.0 mm Hg at 12 months (n = 2 1) and 14.2 +/- 4.2 mm Hg at 24 months (n = 8). Postoperatively, only two patients needed anti-glaucoma medications to keep the IOP below 21 mm Hg. Conclusions: The Ex-PRESS (TM) device was found to be safe and effective with few complications when it is implanted under a scleral flap even in the high-risk patients studied.