Five-Year Real-World Outcomes of iStent inject W® Combined with Phacoemulsification in Ocular Hypertension and Primary Open-Angle Glaucoma
This five-year retrospective study demonstrates that combining iStent inject W® with phacoemulsification provides sustained intraocular pressure reduction, durable medication burden reduction, and long-term structural stability in patients with ocular hypertension or primary open-angle glaucoma, supporting its effectiveness as a long-term management strategy.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Glaucoma is a silent thief of sight, a group of eye diseases that slowly damage the optic nerve, the cable that carries images from the eye to the brain. The most common form, known as primary open-angle glaucoma, usually develops without pain or warning signs until vision is already lost. The single most important factor doctors can control to stop this damage is the pressure inside the eye. For decades, the standard way to lower this pressure has been daily eye drops. While effective, these drops can be difficult for patients to remember, often cause irritation to the surface of the eye, and require a lifelong commitment that many find burdensome. When drops fail or are too difficult to manage, surgeons traditionally turn to more invasive operations that carry higher risks and longer recovery times. In recent years, a middle path has emerged: minimally invasive surgeries that aim to help the eye drain fluid naturally, offering a safer alternative with fewer side effects.
A team of researchers at Virgen Macarena University Hospital in Seville, Spain, set out to see how well one of these newer procedures holds up over the long haul. They focused on a tiny device called the iStent inject W, which is implanted during cataract surgery to create a small bypass for fluid to leave the eye. While earlier studies showed the device worked well for a few years, there was a gap in knowledge regarding its performance over a full five years in the real world, outside of tightly controlled clinical trials. To fill this gap, the researchers looked back at the medical records of 149 patients who had received the device, either alone or combined with cataract surgery, and tracked their progress for up to five years.
The study followed these patients through a series of check-ups, measuring their eye pressure, counting how many eye drops they needed, and checking their vision and the health of their optic nerves. The results offered a reassuring picture of long-term stability. Immediately after the surgery, patients saw a significant improvement in their vision, a result consistent with the fact that many were also having cataracts removed. Over the next five years, the pressure inside the eye showed a steady downward trend. While the drop in pressure was statistically very clear in the first few years, the data at the three-year and five-year marks showed a continued, gentle decline that, while not reaching the highest level of statistical certainty due to the smaller number of patients remaining in the study, still pointed in the right direction.
Perhaps just as important as the pressure numbers was the change in the patients' daily lives. The number of eye drops required to manage the condition dropped significantly at every single follow-up visit. This reduction in medication burden is a major victory, as it means fewer side effects and less reliance on daily routines that can be hard to maintain. The researchers also looked at the structural health of the eye, using advanced imaging to measure the thickness of the nerve fibers and the shape of the optic nerve. These measurements remained remarkably stable throughout the five years, suggesting that the device helped preserve the eye's architecture. The visual field, which maps how much a person can see to the side, showed a very slight decline over time, but this was consistent with the natural, slow progression of glaucoma even when treated, rather than a failure of the surgery.
The study also uncovered some interesting differences between patient groups. Men tended to have slightly lower eye pressure after the surgery compared to women, and patients with ocular hypertension, a condition where pressure is high but no nerve damage has occurred yet, had higher pressure levels than those with established glaucoma. The researchers noted that these differences likely reflect natural variations in eye anatomy rather than a difference in how well the surgery worked for different people. As with any long-term study, the number of patients available for the final five-year check-up was smaller than at the start, as some people moved away or stopped returning for routine visits. Despite this, the data that was available told a consistent story.
The findings suggest that the iStent inject W provides a durable solution for lowering eye pressure and reducing the need for medication over a five-year period. It appears to be a safe and effective way to manage glaucoma and ocular hypertension, offering a stable alternative to long-term drop therapy. By maintaining the structural health of the eye and keeping pressure in check, this approach supports the idea that minimally invasive surgery can be a valuable part of a long-term plan to protect vision. The study reinforces the potential of these tiny devices to change the management of glaucoma, offering patients a path that is less dependent on daily drops and more focused on sustained, structural support for the eye.
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