CLINICAL

  specialty eye care

Treating Glaucoma with Stents

An alternative for non-compliance to topical medications in mild to moderate glaucoma patients

LEO P. SEMES, O.D., F.A.A.O., BIRMINGHAM, ALA.

There are more than two million persons in the United States with glaucoma — a number that, according to the National Eye Institute, is projected to triple by 2050. This chronic condition is often discovered and managed primarily by optometrists, giving us a bird’s eye view of how glaucoma impacts patients’ quality of life.

Currently, topical medications are the most widely used therapy to control this chronic disease. This strategy is effective when used as prescribed, but numerous studies reveal patient compliance to the prescribed regimen is abysmal.

In fact, the Glaucoma Adherence and Persistency Study (GAPS) found that only 10% of patients were 100% persistent in filling their prescriptions. And, that number decreased to 2% when a second glaucoma medication was prescribed, according to a study from Investigative Ophthalmology & Visual Science.

In addition, studies reveal compliance to topical glaucoma treatment is particularly challenging among patients who have less severe disease states (generally newly diagnosed).

The optic nerve shows glaucomatous damage. If cataract surgery is planned, the patient becomes a candidate for MIGS.

The good news: Micro-Invasive Glaucoma Surgeries (MIGS) provide an alternative to topical medications in selected mild to moderate open-angle glaucoma patients, solving the non-compliance to medication problem and improving the quality of life of these patients.

Here, I provide an overview of MIGS and the optometrist’s role in managing these patients.

MIGS overview

Through MIGS, one or more stents are implanted through the same clear corneal incision during phacoemulsification to create a pathway through the trabecular meshwork. This pathway allows aqueous to drain from the anterior chamber into Schlemm’s canal, and thus, lower IOP. MIGS does not substantially alter the cataract procedure in any way.

A study from Ophthalmology revealed that in FDA trials, 85% of patients who received a glaucoma stent in conjunction with cataract surgery were medication free at one year post surgery. The healing time, inflammation and time to regain visual acuity were similar to patients who underwent cataract surgery alone.

Surgical risk

Cataract surgery is a procedure that has an extremely low risk of complications. Similarly, implantation of the stent is a relatively uncomplicated adjunct during the procedure.

Comanagement

Optometrists play a key role in the co-management of stent implantation. Many optometrists participate in the treatment from the first post-operative day.

Post-operative protocols vary according to the surgeon’s preference and experience. However, the typical protocol consists of a prophylactic antibiotic, usually a fluoroquinolone and anti-inflammatories (NSAID and/or steroid). The antibiotic is used during the first post-operative week, and the anti-inflammatories for an additional three to four weeks.

Elevated IOP is the most frequently encountered complication. When this does not resolve spontaneously after the first week, topical IOP-lowering drops can be prescribed situationally.

Following the implantation of stent(s), I advise my patients to stop with their topical hypotensive medications. I evaluate their IOP during the one- to three-months post-operative period and again every three months for one year to make sure it is (they are) stable, only reintroducing medications if necessary. I stress to these patients that continued surveillance for escape of IOP control or progression, as detected by functional or structural measures, is important because POAG is rarely symptomatic, except in advanced stages.

If a patient requires additional topical drops to maintain IOP, I review compliance and the ways to increase it. For example, sometimes this takes the form of a reminder cue, such as keeping the bottle near a sink or on a nightstand for the sake of consistency.

Following the first year, I continue to monitor my patients’ visual field stability and optic nerve condition annually.

New alternatives

As optometrists, our patient relationships often span many years and form strong bonds. Though we are fervently trying to educate them on the importance of complying with medical regimens, it is very frustrating to notice the side effects and see the negative impact on their quality of life. A surgical option that can reduce or eliminate the burden of topical medications with a minimal risk profile is a welcome alternative for many of my patients. OM

A portion of this article was contributed by Adrianne Resek, a medical writer at Pascale Communications, a public relations firm that represents Glaukos Corporation, maker of iStent Trabecular Micro-Bypass Stent.

Dr. Semes is a professor of optometry and clinical assistant professor in the School of Nursing at the University of Alabama at Birmingham and a member of the AOA. Dr. Semes can be reached at leopsemes@gmail.com. Send comments to optometricmanagement@gmail.com.