Glaukos announced that results of an international glaucoma study published in Ophthalmology Glaucoma showed standalone implantation of two iStent Trabecular Micro-Bypass Stents in newly diagnosed primary open-angle glaucoma (POAG) eyes achieved a 35.3% reduction in mean IOP to 16.5 mmHg after 5 years of follow-up.
The purpose of this prospective, randomized, controlled, multi-surgeon clinical trial was to evaluate the 5-year safety and efficacy of two iStents vs. topical prostaglandin as an initial intervention in POAG subjects who had not had prior glaucoma treatment of any kind. A total of 101 subjects were randomized in a 1:1 ratio to receive either two iStents in a standalone procedure or once-daily topical travoprost, a commonly prescribed prostaglandin. At 5 years, results showed:
- Mean diurnal IOP was 16.5 mmHg (35.3% reduction; P<0.0001) for the stent group vs. 16.3 mmHg (35.1% reduction) for the travoprost group, excluding eyes in both cohorts that underwent cataract surgery during follow-up.
- Treatment success – defined as mean diurnal IOP of 6 mmHg to 18 mmHg without add-on medication or secondary glaucoma surgery – was achieved in 77% of stent eyes vs. 53% of travoprost eyes (P=0.04).
- Seventeen percent of stent eyes vs. 44% of travoprost eyes required add-on medication.
- The need for add-on medication arose at a slower rate in the stent group than in the travoprost group, especially after two years of follow-up. Study authors observed that from two to five years of follow-up, add-on medications were initiated in roughly double the number of travoprost eyes vs. stent eyes.
- The safety profile was excellent in both groups throughout follow-up.
“These results illustrate the enduring efficacy and safety of using multiple trabecular bypass stents in a standalone procedure as initial intervention to manage IOP in newly diagnosed, treatment-naïve glaucoma patients,” Robert D. Fechtner, MD, an ophthalmic surgeon based in Syracuse, NY and lead author of the Ophthalmology Glaucoma article, said in a company news release. “Topical ocular hypotensive medications are typical first-line glaucoma therapy but these drugs can be ineffective due to high rates of patient non-adherence, ocular surface damage, cost and other factors. This study shows that not only are Glaukos’ iStents as effective as once-daily topical travoprost in controlling IOP, but they also succeed at maintaining IOP reductions over the long-term with fewer additional medications.”
Three-year outcomes of this study were published in 2016 in Ophthalmology and Therapy. The most recent article detailing five-year outcomes may be accessed online here.
“This latest publication represents the first-ever five-year, protocol-driven, randomized evaluation of standalone iStent implantation in newly diagnosed glaucoma patients,” said Thomas Burns, Glaukos president and chief executive officer. “Moreover, it adds meaningful outcomes data to the growing body of peer-reviewed evidence that implantation of a single or multiple iStents can reliably achieve sustained IOP reductions in an elegant, tissue-sparing procedure with a highly favorable safety profile.”
Glaukos, the study sponsor, is the pioneer of Micro-Invasive Glaucoma Surgery, or MIGS. The FDA approved the company’s first MIGS device, the iStent, in 2012 and approved its second-generation iStent inject Trabecular Micro-Bypass System in 2018. Inserted through a small corneal incision made during cataract surgery, the iStent is designed to reduce IOP by restoring the natural physiological outflow of aqueous humor. The iStent inject relies on the same fluidic method of action but is designed to deploy two stents into separate trabecular meshwork locations through a single corneal entry point for enhanced IOP reduction and procedural ease. The iStent inject is also approved for use in conjunction with cataract surgery or as a standalone procedure in the European Union, Armenia, Australia, Brazil, Canada, Hong Kong, Singapore, South Africa and other international markets.