Washington, DC: An advisory panel has voted to recommend approval for a new glaucoma treatment: the iStent Trabecular Micro-Bypass Stent, to be used in combination with cataract surgery. The stent is used to treat primary open angle glaucoma, the most common form of glaucoma.
In primary open angle glaucoma, a rise in intraocular pressure is caused by clogging of the drainage angle. This prevents fluid from leaving the eye and pressure to increase as new fluid is produced. Currently, there are several approved treatment options for glaucoma, including pressure-reducing eye drops, canaloplasty, and filtering microsurgery.
The iStent is essentially a tiny tube, similar to the vascular stents that are used to support arteries during angioplasty. This tiny tube, which is inserted during cataract surgery, allows increased drainage of intraocular fluid, reducing the intraocular pressure.
The FDA advisory panel reviewed research data from studies submitted by the manufacturer and considered whether there was reasonable assurance that the device was safe, effective, and that the benefits of the device likely outweighed its risks. The panel voted 7-1 that there was “reasonable assurance” that the iStent was reasonably safe for use. The panel also voted 6-2 that there was “reasonable assurance” that the stent was effective at reducing IOP. Finally, the panel voted 7-1 that there was “reasonable assurance” that the benefits of the device outweighed its risks. In every case, the recommendations were for placement of the stent during cataract surgery for the treatment of elevated IOP for patients with mild to moderate open angle glaucoma currently being treated with ocular hypotensive medication.
The primary reservation expressed by the committee was that, although the device was safe, its effectiveness seemed to be relatively low. Furthermore, “the panel noted a lack of effectiveness at 24 months and recommended that the indication for use reflect the temporary nature of the device’s effectiveness.” For more information, you can read the advisory panel minutes here.
Since there are currently many treatment options for glaucoma, it is uncertain whether this new treatment would benefit very many people. Currently, many surgeons recommend combined glaucoma / cataract surgery, especially for people with relatively mild glaucoma. For patients with advanced glaucoma, separate surgery is more often recommended.
To learn whether combined glaucoma and cataract surgery might be a good treatment for you, talk to an ophthalmologist in your area.