Glaucoma is a challenging disease to manage for both the patient and doctor. It's quite insidious, causing very slow visual loss that can be difficult to perceive, especially in its early stages; and the therapies we prescribe often have associated side effects that are immediate and noticeable, in contrast to the asymptomatic nature of the disease we're treating. Furthermore, our therapies are not currently able to reverse vision loss that's already occurred or takes place during treatment, despite our best efforts.

The stakes are high; besides vision loss, disease progression associated with non-adherence to medical therapy can be very costly. For example, the average cost of treatment, per patient per year, ranges from $623 for a glaucoma suspect to more than $2,500 for a person with end-stage disease.1 Not surprisingly, studies have shown that increased costs are associated with higher baseline intraocular pressure, higher baseline stage, amount of medication and use of surgery.2 Furthermore, a study of four countries in Europe found that costs for home assistance went up by a factor of three when patients reached late-stage glaucoma.3

At the same time, effective glaucoma treatment makes a sizable difference. One study used a computer simulation model to compare the projected cost-effectiveness of glaucoma assessment and treatment under conditions of no treatment, conservative treatment efficacy and optimistic treatment efficacy.4 The simulation followed a hypothetical group of 20 million people from age 50 to death or age 100. Increasing the efficacy of treatment lowered the projected costs from $46,000 per patient to $28,000. And of course, a major factor affecting treatment efficacy is patient adherence.

Right now, we have a steadily increasing elderly population in the United States, making the potential cost consequences of medication adherence even more apparent. So early detection and appropriate treatment—including getting the patient to adhere correctly and consistently to the treatment plan—could really make a difference. (Note that the term "adherence" is preferable to "compliance"; the latter implies that the physician is making all the care decisions and the patient is passively following along. Adherence implies a more collaborative and patient-centered process, in which the patient plays a major role in formulating an individualized treatment program that accommodates his or her preferences, needs and limitations.)


The Patient as Partner

Unfortunately, glaucoma and the underlying disease progression are associated with multiple inherent obstacles to patient adherence. Some of these involve difficulties adhering to the treatment regimen, including individual patient issues such as arthritis or Alzheimer's disease. Many other obstacles are situational in nature, such as work-related issues and problems encountered while traveling.

All of these obstacles are exacerbated by the fact that glaucoma is a chronic long-term disease. The physician-patient relationship may span 40 or 50 years, and it's our job as physicians to try to maintain controlled IOP levels throughout this time period. For a child with pediatric glaucoma, we may be talking about a period of 80 to 100 years. This can be contrasted to the acute time course associated with cataract surgery, where the success of the surgical treatment can be evident immediately.

A key to making glaucoma treatment work is encouraging the patient to think of himself as your partner in treating his disease. The more the patient is a part of the decision-making process, the more likely he is to buy into the treatment and use the medications appropriately. Besides, the best doctor/healer is someone who understands the impact of the disease and has the most to gain or lose from it. Ideally, that's the patient.

It's also important to say, "If you want my help as a physician, you have to be truthful with me. Don't assume that I'll get upset with you if you admit you took a drug holiday; I'll understand if you share your reason with me. Don't just tell me what you think I want to hear. Tell me the truth. How is the disease affecting you? Are you okay with the therapy? Do you have questions about my instructions? You have to help me because I can't read your mind."


What Determines Adherence?

Because patient adherence is so important, it's worth considering what factors interfere with adherence or enhance it. There are at least two ways to look at this: from the doctor's perspective and the patient's perspective.

Several years ago the World Health Organization published a report5 listing five key factors that they found to be related to patient adherence:

   • Understanding the importance and threat of the illness, and the benefits of treatment. If patients don't grasp the danger inherent in non-adherence, they'll have far less motivation to go to the trouble of taking the medications. Likewise, knowing how and why the treatment might save their vision is equally critical.

   • Understanding the burden of the treatment. Unexpected, unpleasant side effects can lead a patient to doubt both the value of the treatment and the doctor's credibility. On the other hand, knowing what to expect, and (if possible) the reason the side effect occurs, encourages the patient to continue with the regimen.

   • Knowing what to do and how to do it. How do I take the eye drops? Should I lie down? How many drops is one dose? How do I know that I've gotten the right number of drops onto my eye?

   • Social and instrumental support and resources. Many patients simply cannot manage to take the drops correctly without assistance.

Around the same time the WHO published its paper, we conducted a study designed to identify and describe common obstacles to medication adherence from the patient's perspective.6 We interviewed 48 glaucoma patients about potential obstacles to their adhering to the prescribed treatment regimen. Seventy-one unique situational obstacles were reported, which we classified into four major categories:

   • Medication regimen factors. These include side effects associated with the eyedrops, such as fatigue or redness, and the cost of the medications. These problems were cited about one-third of the time.

   • Personalized factors. Sixteen percent of the obstacles mentioned fell into this category, including problems such as patient forgetfulness; arthritis making it hard to open the bottle; and shaking hands as a result of Parkinson's disease.

   • Provider-related factors. These include the doctor not fully explaining the disease or its subsequent treatment. These factors only constituted 3 percent of the obstacles cited.

   • Situational/environmental factors. Almost half of the obstacles mentioned fell into this category. Here, aspects of the patient's current situation made it difficult to effectively incorporate the drops into the everyday schedule. Obstacles included: not having someone at home to help them with the drops; major life events such as a loved one going into the hospital (which often cause the patient to feel guilty about focusing on his own medical condition); competing activities; changes in routine that upset the patient's normal schedule; and traveling. The latter often includes forgetting to bring the medication on the trip. (The difficulty of refilling a prescription in a foreign country should not be underestimated.)


The Health Literacy Factor

Given the inherent problems associated with long-term treatment of glaucoma, educating the patient is a major concern. Among other things, the patient needs to understand why adherence is so important, and why he needs to be truthful in communicating how he's feeling (and how he's seeing) and how successful he's been at following the treatment regimen.

A key piece of this puzzle is having appropriate educational materials and written instructions for the patient. Most practices have these, but there's a potential big problem: Many of the handouts offered to patients are written at a higher level of grammar and literacy than what the average patient is equipped to fully understand—and there is indeed a positive relationship between health literacy and the number of refills a patient obtains.

We as physicians tend to create and/or distribute education materials for people who have a high level of health literacy. (After all, we're writing and reviewing them.) We may assume, for example, that patients understand what we mean when we say that glaucoma is a chronic disease—but many patients may not know what "chronic" means. One study found that only 48 percent of patients read at or above the ninth-grade level, and 12 percent read at or below the third-grade level.7 As a result, it makes sense to target your educational materials to the health literacy of your patient population.

The best approach is to have more than one type of explanatory/instructive materials available. For example, you could have three different versions of a one-page sheet explaining how to take drops. One could be very straightforward, written at a third- or fourth-grade level, explaining that the drops help control eye pressure, which prevents blindness. Another version could be targeted at patients who want to know a lot about the medications (i.e., these specific drops reduce the production of aqueous flow, which reduces the pressure on the optic nerve, etc.) In our practice we have multiple versions available, up to and including reprints of my scientific papers for patients who love intricate details and sophisticated explanations. I have even photocopied textbook chapters for some of my college-professor patients. The bottom line is that I try to provide educational materials based on what the patient wants and what I believe the patient is able to understand and appreciate.

One very helpful strategy is to provide an illustrated fact and dosing sheet. We cannot assume that patients know how to take drops; they need to be shown. (Alan Robin, MD, has presented remarkable video footage at recent glaucoma meetings showing how much trouble many patients encounter just getting the right number of drops onto their eyes.) You can provide an information sheet with illustrations showing patients how to hold the bottle, the correct quantity to apply and so forth. (If you tell them to use the drops three times a day, they may not realize that you mean for them to use a single drop three times a day.) The more specific the illustrations and instructions, the better.

This goes back to what I consider an essential part of treating glaucoma: We as physicians must individualize therapy for our patients. Each and every one of our patients has a different socioeconomic status, educational background, interest level and health literacy. To treat each patient effectively, all of these factors have to be taken into account.


More Ways to Improve Adherence

Here are some other strategies that help to ensure that patients take their medications in an effective manner:

   • Support the patient's confidence. The patient needs to have faith that following the treatment protocol is manageable and will pay off by maintaining his vision. Remind him that active treatment is proven to benefit most patients, that there are more options if the current option doesn't help enough, and that new options are on the horizon. So, there is every reason to continue with the program and expect a good outcome.

This also means we have to be there for patients who don't do as well. We might like to believe that every patient will have a positive outcome, but some patients will lose vision regardless of what we do. We must give them hope without lying to them, and reassure them that we will be there for them, even if the visual result is imperfect.

   • Address the patient's fears. One important way to help ensure adherence is to minimize emotional distress by fully addressing the patient's concerns. The reality that glaucoma can potentially lead to bilateral blindness is indeed a frightening prospect, and I believe it's always in the back of the patient's mind. You have to reassure patients that if they work with you they have a good chance of retaining their vision throughout their functional life. Also, patients should be reminded that they don't need to worry about going blind in the near future, since glaucoma is a slowly progressive disease.

One question patients often ask is: Why me? You can explain that there may be a genetic component, and issues such as nearsightedness may contribute to the problem; or the patient may have a greater risk because of being African American. Information is crucial, at least in part because nothing is more frightening than the unknown, and fear undermines adherence.

Then there is the cost of the medicines and the follow-up. We sometimes assume that this is the only medicine the patient has to worry about, but most of these patients are elderly and have other chronic diseases for which they take medicine. I've heard patients say, "How can I afford all of these medicines? I've got hypertension, diabetes and heart disease—and every physician is telling me that his medicine is the most important." It's a real challenge, both for the patient and the physician. To manage this issue we as clinicians have to be flexible, adaptable and think about the long term.

   • Be on the lookout for adherence lapses. If you look at any of the adherence studies, people sometimes take drug holidays. So you have to constantly be checking for this. When you see the patient, ask whether he's had any problems maintaining the program, and reenergize his commitment and desire for a positive payoff.

   • Work with each patient's beliefs about the disease. Whether a patient is adherent often comes down to psychology. For example, if a patient is in denial about having the disease, he's not likely to follow your instructions. On the other hand, some patients will panic—"Oh my God, I've got a chronic blinding disease." Some will be fatalistic about their prognosis: "I'm going to go blind; there's nothing I can do. The doctor says to take these drops, but they're not going to help me." Some patients will say, "I'm going to fight this; I'm going to learn everything there is to know about this disease. I'm not going to take this lying down." Your patients' attitudes will probably cover the full spectrum.

Most doctors don't think much about this. They say, "Your pressure is 22, let's put you on this drop. I'll see you in four months." If patients complain about mild side effects, many doctors just say, "Bear with it." Instead, they could say, "I know you're not excited about the possibility of using the laser, but if you can't take the drops almost 100 percent of the time, you're doing yourself a disservice."

Part of this is being a good listener. It's great to be a good surgeon with a firm grasp of pharmacology and physiology, but to deliver the best care you have to hear what the patient is saying. Plus, patients feel a lot better just knowing that they've been heard. I find that when I listen to my patients, even if the disease isn't better, they leave my office more upbeat, and I've given them more hope for the future.

   • Ask your staff to note any comments made by the patient. Often the patient will tell your technician that he hasn't been taking the drops, but he won't tell you. Patients don't want to disappoint you (the authority figure) and don't want to be reprimanded. So your staff may be in a better position to discover that a patient is having difficulty with his drops.

   • Enlist caregivers. Some patients are too proud to accept help, even when they really need it. One very stubborn patient of mine had Parkinson's disease. Sometimes his pressures were very high; sometimes they were well-controlled. When his Parkinson's acted up, he didn't get the drops in, but when he was better, he was able to use them. I said to his wife, why doesn't he let you give the drops? She said, "He's too proud. He wants to do it himself." Things only improved after I pleaded with the patient not to be so proud.

   • Link the dosing to the patient's schedule. If a patient is having trouble remembering to take the drops, try suggesting that he use the drops in connection with a daily routine. If the patient says, "I fall asleep before I get around to taking the drop," you can ask what he does before he goes to bed every night. For example, you might suggest using the drop after he brushes his teeth.

   • Address work-related issues. If a patient has an unusual work schedule—for example, if he works the night shift—this can lead to the patient not being sure about when to take the drop. If you discover this is a concern, you can help the patient figure out a practical solution.

   • Choose a treatment that enhances adherence. Some patients can't manage drops more than twice a day, so it may not be effective to prescribe a drop that has to be taken three times a day. On the other hand, that's not always the case. Again, the main rule is to customize the treatment to meet the needs and limitations of each patient.


The Key: Individualize Therapy

Glaucoma is a disease that's fraught with challenges for patient adherence. That's why it's so important to treat adherence as a major factor when we're trying to achieve the best possible outcomes.

Perhaps the most important point to remember is that we need to individualize therapy. Glaucoma is not a good candidate for a one-size-fits-all therapy. We need to look at each patient carefully; elicit his concerns; assess his needs; and consider the practical issues he faces in his particular circumstances, whether those involve forgetfulness, cost, arthritis or other factors. Then we need to structure our therapy to address those specific obstacles.

Dr. Tsai is Robert R. Young Pro-fessor and chair of the Department of Ophthalmology and Visual Science at Yale University School of Medicine in New Haven, as well as Chief of Ophthalmology at Yale-New Haven Hospital. He is an ad hoc consultant for Alcon, Allergan, Merck and Pfizer.


1. Lee PP, et al. A multicenter, retrospective pilot study of resource use and costs associated with severity of disease in glaucoma. Arch Ophthalmol 2006;124:1:12-19.

2. Lee PP, 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.

3. Thygesen J, et al. Late-stage, primary open-angle glaucoma in Europe: Social and health care maintenance costs and quality of life of patients from four countries. Curr Med Res Opin 2008;24:1763-1770.

4. Rein DB, Wittenborn JS, et al. The cost-effectiveness of routine office-based identification and subsequent medical treatment of primary open-angle glaucoma in the United States. Ophthalmology 2009;116:5:823-32.

5. Adapted from World Health Organization. Adherence to Long-term Therapies: Evidence for Action. 2003. Geneva, Switzerland.

6. Tsai JC, et al. Compliance barriers in glaucoma: A systematic classification. J Glaucoma 2003;12:5:393-8.

7. Muir KW, et al. Health literacy and adherence to glaucoma therapy. Am J Ophthalmol 2006;142:2:223-226.