Treatment offers reductions of eye pressure

iStent Trabecular Micro-Bypass Stent may just be another case of “less is more” for those suffering with glaucoma.

Willis-Knighton Eye Institute surgeons Dr. Christopher Shelby and Dr. Wyche T. Coleman III are the first in this region to offer this new procedure as a treatment option to reduce eye pressure for patients who have both cataracts and glaucoma.

The iStent is implanted during cataract surgery to reduce eye pressure in adult patients with mild-to-moderate open-angle glaucoma being treated with glaucoma medications. In clinical trials, the FDAapproved device has been shown to safely reduce eye pressure, which is the primary cause of open-angle glaucoma.

“This is great news for people with glaucoma who need cataract surgery,” Shelby said. “The eye drops used to treat glaucoma can be difficult to administer and expensive. With iStent, many patients will need less medication to control their eye pressure, and some may not need prescription eye drops at all.”

Studies have shown that more than 90 percent of patients with glaucoma do not comply with their ocular medication dosing regimens, and nearly 50 percent discontinue taking their medications before six months, which can lead to serious problems, including vision loss.

iStent is termed as “microtechnology” and is the smallest medical device ever approved by the FDA.

“Because it is so small, the patient cannot see or feel it after the procedure,” Coleman said. “While it is not apparent to the patient, it can be successful in reducing eye pressure. And it doesn’t significantly extend the length of the surgery and has a similar safety profile to cataract surgery alone.”

According to Opthobook.com, openangle glaucoma, also called chronic glaucoma, is what the majority of glaucoma patients suffer from. In this condition, aqueous fluid does not drain well out of the eye. One theory is that the trabecular meshwork filter may have microscopic particles clogging it and slowing down fluid movement.

Glaukos Corporation is a privately held ophthalmic company located in Laguna Hills, Calif., dedicated to researching and developing microtechnologies to improve glaucoma therapy. The company developed the iStent Trabecular Micro- Bypass Stent, which is intended to improve natural physiological aqueous outflow and reduce intraocular pressure in open-angle glaucoma patients.

Glaukos.com states glaucoma is the second-leading cause of blindness, affecting approximately 78 million people worldwide.

Glaucoma is a chronic, irreversible condition that progresses slowly over time. It cannot be cured so treatment is aimed at slowing vision loss by managing intraocular pressure, which builds up within the eye and damages the optic nerve. Glaucoma treatment has traditionally required patients to use multiple types of prescription eye drops for the rest of their lives, and sometimes undergo complex and invasive eye surgery.

In an international study by Glaukos Corporation, a single iStent was implanted through the same incision used for cataract surgery in a consecutive series of 62 eyes of 43 subjects.

In 39 eyes followed through three years, the mean IOP at three years was 14.9 mmHg, compared to a mean preoperative IOP of 23.4 mmHg.

In the same 39 eyes, the mean number of glaucoma medications used three years following surgery declined to 0.3, compared to a mean of 1.9 medications at subjects’ preoperative visits. No operative complications occurred during the cataract surgical procedure or during the stent implantation procedure. Over the three-year follow-up period, five secondary surgeries, two postoperative ocular sequelae and two non-ocular adverse events were reported.

“These data show that implantation of a single iStent in conjunction with microincisional cataract surgery provided a sustained reduction in IOP and medication burden with favorable safety through three years postoperative for this patient population with moderate and varied types of glaucoma,” Neuhann said. “In the study, the decision to implant the iStent was based on the wish of the patient to reduce or possibly eliminate the burden of topical glaucoma medications and the intention to offer a surgical treatment for glaucoma with a favorable safety profile. We did not qualify subjects based on specific inclusion or exclusion criteria. Consequently, the population studied in this series was representative of a European clinician’s real-world experience with a typical patient group.”

–Bonnie Culverhouse

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WK Eye Institute is a group of ophthalmologists and optometrists located on the North, South and Pierremont Willis- Knighton campuses. Surgeons perform eye surgery at WK Eye Surgery Center and WK Refractive Surgery Center, where they have access to one of the largest arrays of eye equipment and services in the region.