Patients with primary open-angle glaucoma implanted with two iStents experienced a similar IOP reduction and required fewer add-on medications compared with patients treated with a once-a-day travoprost.
While patients with glaucoma are commonly treated first with medications, the 5-year data from a prospective, randomized clinical trial suggest early surgery with two iStents (Glaukos) could provide similar IOP control when compared with once-a-day travoprost, study co-author Robert D. Fechtner, MD, of SUNY Upstate Medical University, told Ocular Surgery News.
“As we will start seeing sustained delivery medications that are proposed to be implanted in the anterior chamber repeatedly, should we not consider a device that might have 5 years or greater efficacy? Once we decide to offer an intraocular treatment to overcome the burden of daily therapy and the challenge of nonadherence, we would do well to consider both sustained delivery medication systems and surgical devices,” Fechtner said.
Effective IOP reduction
The study included 101 newly diagnosed and treatment-naive patients with primary open-angle glaucoma who were randomly assigned 1:1 to receive either two iStents in a stand-alone procedure or treatment with once-daily topical travoprost.
Patients were followed for 5 years, and treatment success was defined as a mean diurnal IOP of 6 mm Hg to 18 mm Hg without add-on medications or a secondary glaucoma surgery. Assessment of IOP was measured by two observers, one at the slit lamp and another recording the IOP.
At 5 years, 90 eyes, 49 in the iStent cohort and 41 in the travoprost cohort, remained in the study. The mean diurnal IOP was 16.5 mm Hg, a 35.3% reduction from baseline IOP, in the iStent cohort compared with 16.3 mm Hg, a 35.1% reduction, in the travoprost group.
Treatment success and safety
Treatment success was achieved in 77% of iStent eyes compared with 53% of travoprost eyes, a statistically significant difference (P = .04). Additionally, 17% of iStent eyes required an add-on medication compared with 44% of travoprost eyes (P = .017).
Patients in the iStent cohort who required add-on medications needed them at a slower rate than the travoprost cohort. Between years 2 and 5 of the study, patients in the travoprost cohort were prescribed added medications at double the rate of the iStent cohort.
The safety profile for both cohorts was excellent throughout the 5-year follow-up. One eye in the iStent group had an intraoperative hyphema that resolved without intervention by day 1, and one eye had mild cyclodialysis. Both were attributed to unexpected patient movement during surgery.
“Here is a treatment-naive population who had two iStents as a stand-alone procedure. We have 5-year follow-up. I acknowledge this is not a systematic clinical trial data collection for 5 years, but the ophthalmologist who followed the patients did not see corneal problems, late dislocations or other serious adverse events,” Fechtner said. – by Robert Linnehan
- Fechtner RD, et al. Ophthalmol Glaucoma. 2019;doi:10.1016/j.ogla.2019.03.004.
- For more information:
- Robert D. Fechtner, MD, can be reached at Department of Ophthalmology & Visual Sciences, SUNY Upstate Medical University, 550 Harrison St., Suite L, Syracuse, NY 13202; email: firstname.lastname@example.org.
Disclosure: Fechtner reports he receives grant support from Research to Prevent Blindness and is a consultant with Glaukos.