Half a decade of data on the second generation iStent inject has shown a significant reduction in intraocular pressure (IOP) and medication burden in glaucoma patients.
While there are more than 200 publications on Glaukos iStent technologies, a new paper entitled: ‘iStent inject trabecular micro-bypass with or without cataract surgery yields sustained 5-year glaucoma control’, is the first peer-reviewed publication to present five-year data on the second generation iStent inject.
The paper, published in Advances in Therapy online in February, is based on a prospective longitudinal study which assessed five-year outcomes following implantation of two iStent inject second-generation trabecular micro-bypass stents, either with or without concomitant cataract surgery, in eyes with various severities of open-angle glaucoma.
The study enrolled 125 consecutive eyes treated with iStent inject trabecular micro-bypass (81 combined, 44 standalone) by a single glaucoma surgeon (Fritz Hengerer, Germany). An impressive 97% of eyes (121/125) completed five-year follow-up.
Although the cohort had relatively high glaucoma medication burden preoperatively (mean preoperative IOP of 23.5 ± 6.2 mmHg on 2.68 ± 1.02 mean medications), nearly half of eyes were medication-free by the end of five years, while mean IOP decreased by nearly 10 mmHg.
According to the authors, the reductions in IOP and medication were similar in magnitude and consistency over time regardless of whether stenting was performed as a standalone surgery or in combination with phacoemulsification.
Among the paper’s key findings was that in both the combined and standalone groups, clinically and statistically significant reduction from baseline IOP was sustained at all follow-up time points through five years post-operatively.
Mean IOP decreased from 22.6 mmHg preoperatively to 13.8 mmHg at five years in combined eyes (39% reduction), and from 25.3 mmHg to 14.6 mmHg (42% reduction) in standalone eyes.
Similarly, both the combined and standalone subgroups demonstrated reduction in medication burden.
In combined eyes, the average number of medications reduced by 69% (from 2.52 preoperatively to 0.78 medications at five years); the proportion of medication-free eyes rose to 44%.
In standalone eyes, the average number of medications reduced from 2.98 preoperatively to 0.74 medications at five years (75% reduction); the proportion of medication-free eyes rose to 50%.
Over the course of five-year follow-up, a total of five eyes (three combined, two standalone) underwent an additional glaucoma procedure due to the need for additional IOP-lowering beyond what had been achieved with stent implantation.
The procedures, all of which occurred at month one or month six postoperative, included cyclophotocoagulation (CPC) in three eyes and XEN implantation in two eyes. No filtering surgeries were performed in any eye throughout the five years.