Improving Glaucoma Patient Compliance

By Mildred M.G. Olivier, MD, FACS

SLT reduces intraocular pressure and the need for medications.

"Drugs don't work in patients who don't take them." This statement, made by former U.S. Surgeon General C. Everett Koop, MD, resonates among physicians who provide care for patients with glaucoma. On one hand, landmark clinical trials show that lowering IOP and keeping it consistent are key to preventing vision loss. On the other hand, we're increasingly aware of how challenging it can be for patients to fully comply with the necessary treatment regimens, medications in particular, that we prescribe.

For example, while 67% of patients report that they follow their physicians' instructions "extremely closely," 75% admit to some form of noncompliant behavior, 33% don't fill their prescriptions, and nearly 50% discontinue prescribed drops within 6 months.^1-3 Furthermore, poor patient compliance isn't bound to income or socioeconomic levels, and with glaucoma, we have the additional challenge of racial disparities in disease characteristics and care. (See "Racial Disparities in Glaucoma Care" at the end of this article)

In this article, I discuss reasons why patients are noncompliant and what we as physicians can do about it, including using selective laser trabeculoplasty (SLT) as primary, adjunctive or replacement therapy.

Obstacles to Patient Compliance

Viewed from a broad perspective, we find a variety of factors that contribute to glaucoma patient noncompliance with prescribed medication regimens (Figure 1). We see poor providerpatient communication. As a result, patients may not understand their disease and the importance of using their medications. We see problems with physician interaction with the healthcare system, such as a lack of knowledge about drug costs and a lack of awareness of insurance coverage and different formularies. We also see issues related to patient interaction with the healthcare system in terms of issues, such as access to care or the pharmacy or missed clinic appointments.

More specifically, from the patient's perspective, obstacles to compliance can be social/environmental, for example a major life event such as the death of a spouse. Major life events take the patient's focus away from using their medications. We often hear that patients forget to take their medications on vacation. Other obstacles to compliance may be regimen-related. Patients may forget to refill their glaucoma prescriptions or struggle to follow a complicated regimen, especially when they're taking medications for diabetes, hypertension and so on.

Side effects pose a problem for some patients, too. Red or burning eyes often lead to medication discontinuation. In addition, it's difficult for many patients to self-administer their drops. They struggle to direct the bottle, causing drops to miss the eye, or they simply can't squeeze the bottle properly or at all. Both problems interfere with proper dosing, because too much or too little medication is being delivered to the eye.

Among the biggest barriers to compliance, especially in these difficult economic times, is the cost of medications. Those costs are a major factor in the total direct cost of glaucoma (Figure 2).⁴ In one study,⁵ over 5 years, laser trabeculoplasty was associated with the lowest total costs compared with treatment by medication alone or by filtering surgery for patients who weren't adequately controlled by two medications. The average yearly cost of medication ranges from approximately $255 in the beta blocker category to approximately $697 in the combination drug category (Figure 3).⁶ Furthermore, we all know glaucoma patients take an average of 2-3 medications, not just one.

When it comes to insurance coverage, today's patients face two relatively new situations: rising copays and the "doughnut hole" in Medicare Part D. In the latter scenario, many patients find themselves paying out of pocket for all of their medications for extended periods of time. As a result, they may be forced to discontinue treatment. In other cases, patients are losing their insurance coverage altogether because they've lose their jobs.

Improving Patient Compliance

Physicians can improve the extent to which patients follow treatment recommendations by improving education and communication. First, we need to continually reinforce why taking medication is so important. Second, we shouldn't assume patients know how to instill their drops. We should instruct them about proper usage while they're in our offices. Take-home illustrated brochures, such as those available from the American Academy of Ophthalmology, can help. We can also provide printed schedules, so patients can check off medications as they take them each morning, afternoon and evening.

To ensure our educational efforts are working, we can ask patients to bring their medication to appointments so they can show us how they instill their drops, and we can ask which ones they use at which times of day. I try to help patients think about activities they do at specific times of day, then suggest they couple those activities with using their drops. Enlisting family members who accompany patients to appointments to either provide reminders or actually help instill drops is also a good strategy.

At every visit, I make sure I'm restating key educational points for patients and reviewing options that may boost their compliance. When ocular side effects are a concern, for example, we discuss how punctal occlusion or artificial tears might help.

SLT as Part of the Solution

In addition to efforts aimed at modifying patient behavior through better education and communication, physicians can utilize SLT to mitigate problems with compliance. SLT is indicated for the reduction of IOP in patients with open-angle glaucoma. It's effective as primary therapy, adjunctive therapy (for patients already on medications who need further IOP control) and replacement therapy (for patients with controlled IOP who want to reduce medications).

The treatment is delivered using a Q-switched, 3-nanosecond pulsed, frequency-doubled, Nd:YAG 532-nm green laser (Selecta II, Selecta Duet, Selecta Trio, Lumenis, Santa Clara, Calif.).

It provides the IOP-lowering benefits of argon laser trabeculoplasty (ALT) without the coagulative damage that leads to scarring of the trabecular meshwork.⁷ Using a significantly lower energy per pulse than ALT (0.6-1.2 mJ compared with 40-70 mJ), SLT specifically targets pigmented cells, leaving trabecular meshwork intact (Figure 4). Therefore, SLT is believed to improve aqueous outflow and regeneration of the trabecular meshwork. It stimulates the natural mechanisms of the body to recruit macrophages and cytokines that "clean out" the trabecular meshwork, lowering IOP. The larger spot size of SLT (~400 ìm) evenly distributes the laser energy and makes focusing much less of an issue than it is with ALT.

SLT as Primary Therapy

Given the gentler, yet effective, mechanism of action of SLT, I recommend it as primary therapy for most of my glaucoma patients. Whenever I'm planning to start patients on topical medications, I offer the SLT option instead.

As primary therapy, SLT provides IOP reduction equivalent to that of medications. In a prospective, multicenter clinical study of patients with newly diagnosed openangle glaucoma or ocular hypertension, McIlraith and colleagues⁸ found that over 12 months, SLT provided mean IOP reduction of 31%, while latanoprost (Xalatan) provided mean IOP reduction of 30.6%. Similarly, the SLT MED Study Group⁹ found that after follow-up of at least 8 months, patients randomized to receive SLT achieved mean IOP reduction of 6.7 mmHg and patients randomized to receive medication achieved mean IOP reduction of 7.6 mm Hg. So, again, with SLT we have IOP reduction equivalent to medication with less concern about side effects and patient compliance.

In addition, the treatment effects are long lasting. Studies¹⁰ have shown the IOP-lowering effects of SLT to be sustained for as long as 18 months and 5 years. Jindra and colleagues¹¹ reported a 93% success rate for SLT over a 5-year period, defining success as no further treatment required (Figure 5).

SLT as Adjunctive Therapy

Along with our newly diagnosed patients, for whom SLT is an excellent primary therapy, we have those already using topical medication who require further IOP reduction. SLT is effective in this scenario as well. Latina and colleagues¹² studied SLT in patients with open-angle glaucoma who had been treated previously with medication and/or ALT. They found that 70% of all patients treated with SLT had an IOP reduction of at least 3 mmHg. We know the risk of glaucoma progression increases with each 1 mmHg increase in IOP fluctuation. Therefore, the ability to tighten IOP control without the cost and compliance issues of additional medication is a welcome benefit.

In my practice, even when patients declined SLT as primary therapy, I discuss the option with them again before recommending additional medication as part of their treatment regimen.

SLT as Replacement Therapy

We also can consider SLT for patients who express a desire, or financial pressure, to stop taking their medications. In the previously discussed study by Jindra and colleagues,¹¹ more than 50% of patients no longer required medications after receiving SLT therapy. Among patients who had been taking one medication prior to receiving SLT, 86% were able to taper to no medications. The taper rates to no medications for patients previously on two, three and four medications were 62%, 42% and 32% respectively. In another study,¹³ 87% of eyes treated with SLT maintained reduction in medication use by at least one medication at 12 months.

Closer to Ideal Therapy

In general, we can expect glaucoma patients who respond favorably to topical IOP-lowering medications to respond favorably to SLT. While the highest success rates are achieved when SLT is used as primary therapy, the studies cited in this article, and my personal experience, support its benefits as adjunctive or replacement therapy as well. When compared with other treatment options for our glaucoma patients, SLT is:

• Safe − it's not associated with systemic side effects
• Selective − photothermolysis specifically targets pigmented cells, leaving trabecular meshwork intact
• Smart − cellular photoactivation stimulates the body's natural mechanisms to enhance aqueous outflow, and when used as primary therapy SLT is as effective as ALT and medication
• Sensible − it reduces or eliminates the cost and compliance issues associated with medications.

At some point in the future, physicians treating glaucoma may have additional treatment options, such as injectable treatments or medication-releasing contact lenses or implants, all of which could help improve patient compliance. Until that time, however, the efficacy, tolerability and relatively low cost of SLT make it an excellent choice for helping to safeguard our patients' vision.

Dr. Olivier is an associate clinical professor at Rosalind Franklin University of Medicine and Science and Midwestern University, both in the Chicago area.

REFERENCES

1. Osterberg L, Blaschke T. Adherence to medication. N Engl J Med. 2005;353:487-497.
2. National Community Pharmacists Association. December 15, 2006, press release. Take as directed: a prescription not followed.
3. Nordstrom BL, Friedman DS,Mozaffari E, Quigley HA,Walker AM. Persistence and adherence with topical glaucoma therapy. Am J Ophthalmol. 2005;140:598-606.
4. Lee PP, Kelly SP, Mills RP, et al. Glaucoma in the United States and Europe: predicting costs and surgical rates based upon stage of disease. J Glaucoma. 2007;16:471-478.
5. Cantor LB, Katz LJ, Cheng JW, Chen E, Tong KB, Peabody JW. Economic evaluation of medication, laser trabeculoplasty and filtering surgeries in treating patients with glaucoma in the US. Curr Med Res Opin. 2008;24:2905-2918.
6. Rylander NR, Vold SD. Cost analysis of glaucoma medications. Am J Ophthalmol. 2008;145:106-113.
7. Kramer TR, Noecker RJ. Comparison of the morphologic changes after selective laser trabeculoplasty and argon laser trabeculoplasty in human eye bank eyes. Ophthalmology. 2001;108:773-779.
8. McIlraith I, Strasfeld M, Colev G, Hutnik CM. Selective laser trabeculoplasty as initial and adjunctive treatment for open-angle glaucoma. J Glaucoma. 2006;15:124-130.
9. Katz LJ, SteinmannWC, Marcellino GR and the SLT MED Study Group. Comparison of selective laser trabeculoplasty vs.medical therapy for initial therapy for glaucoma or ocular hypertension. Annual Meeting of the American Academy of Ophthalmology, Las Vegas, November 2006. Presentation PO108.
10. Melamed S, Ben Simon JG, Levkovitch-Verbin H. Selective laser trabeculoplasty as primary treatment for open-angle glaucoma: a prospective, nonrandomized pilot study. Arch Ophthalmol. 2003;121:957-960.
11. Jindra LF, Gupta A, Miglino EM. Five-year experience with selective laser trabeculoplasty as primary therapy in patients with glaucoma. Annual meeting of the American Academy of Ophthalmology, New Orleans, November 2007.
12. Latina MA, Sibayan SA, Shin DH, Noecker RJ,Marcellino G. Q-switched 532-nm Nd:YAG laser trabeculoplasty (selective laser trabeculoplasty): a multicenter, pilot, clinical study. Arch Ophthalmol. 1998;105:2082-2088.
13. Francis BA, Ianchulev T, Schofield JK,Minckler DS. Selective laser trabeculoplasty as a replacement for medical therapy in open-angle glaucoma. Am J Ophthalmol. 2005;140:524-525.