Ex–Press Mini Glaucoma Valve (Optonol) Provides Better Long Term Intraocular Pressure Control When Placed Under a Scleral Flap

Abstract

Purpose: To present our initial experience with the Ex–Press (Optonol) miniature glaucoma implant for intraocular pressure (IOP) control.

Methods: Twenty (20) eyes of 20 patients ( 11 males, 9 females ) with medically uncontrolled primary open angle glaucoma ( 11 eyes ) or exfoliative glaucoma ( 9 eyes ) were treated surgically with the use of an Ex–Press mini valve, and prospectivelly followed up for 12 months. In 8 ( 40% ) eyes the mini–valve was placed subconjunctivally just behind the limbus, whereas in 12 ( 60% ) eyes the implant was positioned under a trabeculectomy–like scleral flap.

Results: At one year after surgery, the ‘under scleral flap’ group maintained a significant 41.7% reduction of preoperative mean ( ± SD ) IOP ( 28.2 ± 9.2 mm Hg vs. 16.4 ± 2.8 mm Hg, p=0.001 ). In contrast, the ‘subconjunctival placement’ group of patients, one year after surgery showed similar (p=0.888) IOP measurements ( 19.4 ± 4.9 mm Hg ) to the preoperative values (18.7 ± 3.7 mm Hg ). No serious complications were observed in either group within the study period, but one of the valves in the ‘under scleral flap’ group had to be removed due to conjunctival erosion.

Conclusions: In our hands, the Ex–Press mini glaucoma valve provided a new useful tool in the surgical treatment of glaucoma, however with promising results only with a modification of the proposed surgical technique by placing the valve under a scleral flap.