A proprietary miniature glaucoma device (Ex-PRESS, Optonol Ltd.) implanted under a partial-thickness scleral flap achieved significant decreases in IOP in patients with glaucoma.
In a retrospective, non-comparative case series of patients, Dr. Netland and colleagues implanted the device under a scleral flap in patients with glaucoma who had elevated IOP that was refractory to maximal medical therapy. The investigators defined successful procedures as those in which the postoperative IOP was between 5 and 21 mm Hg with or without additional medication and without the need for further glaucoma surgery. The valve was implanted in 300 consecutive eyes. The mean follow-up period was 17 months (range, 3 to 36 months).
"The . . . miniature glaucoma device implanted under a scleral flap was safe and effective. Blockage of the lumen of the device in a small proportion of patients was effectively treated," Dr. Netland said.
In a previous study, Dr. Netland, Peter Maris Jr., MD, and Kyoko Ishida, MD, compared the outcomes after implantation of the valve with those achieved with standard trabeculectomy.
The average follow-up was 10.8 months (range, 3.5 to 18 months). The investigators reported that, during the early postoperative period, the IOP values in the eyes in which the valve had been implanted were significantly higher than in the eyes that received the standard of care. By the 3-month postoperative evaluation, the degree by which the IOP decreased was similar in both treatment groups, and the number of antiglaucomatous medications did not differ between the groups.
The study showed that the implant shunts aqueous from the anterior chamber into the subconjunctival space adjacent to the limbus.
The investigators reported that "the . . . implant under a scleral flap had similar IOP-lowering efficacy with a lower rate of early hypotony compared with trabeculectomy."