The prevalence of non-adherence with IOP-lowering medications underscores the need for optometrists to frequently re-assess medication use in glaucoma patients and consider therapies that will enable compliance and prevent it from becoming an efficacy-limiting issue.
Salt Lake City-The prevalence of non-adherence with IOP-lowering medications underscores the need for optometrists to frequently re-assess medication use in glaucoma patients and consider therapies that will enable compliance and prevent it from becoming an efficacy-limiting issue, said J. James Thimons, OD, at Optometry's Meeting.
"Reinforcing the importance of using IOP-lowering drops as directed may be the most important thing we can do to maintain disease control and prevent visual loss from glaucoma. Therefore, in addition to reviewing IOP results and findings from imaging and functional studies, eye care providers should be sure to take some time to discuss medication compliance," said Dr. Thimons, medical director, Ophthalmic Consultants of Connecticut.
Even in the best-case scenario (represented by the subgroup prescribed a Q.D. prostaglandin analogue) only about 50% of patients remained on their medication at 1 year postinitiation. he persistence rate was 25% or lower for patients prescribed medications from other classes of IOP-lowering agents, and lowest for patients on beta blockers. Dr. Thimons suggested that his could be explained by the greater risk of systemic side effects with beta blockers compared with carbonic anhydrase inhibitors or alpha agonists.
Data from follow-up to 3 years showed persistence rates generally remained at the level they had reached at 1 year, indicating that patients who initially show poor medication compliance will likely maintain that behavior in the future if it is not addressed, Dr. Thimons said.
Results from other studies conducted in patients with glaucoma as well as in hypertensive and diabetic opulations also show that patients with chronic diseases on average use their medication about 50% of he time, and that compliance is improved by simplifying the dosing regimen.
"There is a wealth of iterature showing poor medication compliance is not just an issue for glaucoma, nd so a lot of the lessons we have learned on how to deal with this problem have evolved out of iterature from internal medicine and other specialties," he said.
Address the elephant in the room
The first step to dealing with non-adherence is to identify it, and so a discussion about medication use between the patient and the eyecare professional should be included in every follow-up visit. Clinicians, however, should recognize that patients generally do not want to disappoint them. Therefore, the best way to elicit honest information is to investigate medication use by asking a direct, open-ended question, said Dr. Thimons.
"Patients want to please their doctors and avoid disapproval. Therefore, if they are asked whether they are using their medication as prescribed, they are likely to answer 'yes,' whether or not it is true," he observed.
"A better approach is to ask patients to describe how they are using their medications. Patients who are not compliant are less likely to be able to give the proper information. Reassuring patients that non-adherence is common and educating them that accurate information on adherence is important for therapeutic decision making are also important elements for creating an environment where patients will feel comfortable giving truthful information," said Dr. Thimons.
Results of a study by Mazze et al. (Am J Med 1984 Aug;77(2):211-217) involving glucose monitoring in a type I diabetes population provide a powerful demonstration of how patients will provide erroneous information to please their doctors. In this investigation, patients were given a glucose meter and sked to keep a 2-week log of their blood glucose results along with the time and date of the test. Unknown to the participants, the glucose meter contained a memory chip that captured and stored the test information.
Comparison of the electronically and selfrecorded data showed three-fourths of the patients recorded glucose values that were lower than the actual result, two-thirds underreported hypoglycemic or hyperglycemic episodes, and 40% entered fictitious data in their logs, writing in test times and results for measurements that were never taken.
"A corollary for this type of behavior among glaucoma patients is the diligent use of IOPlowering drops for a few days prior to a scheduled visit, resulting in an IOP level that suggests good control," Dr. Thimons said.
J. James Thimons, OD
Dr. Thimons is a consultant for or on the medical advisory board for a number of companies that manufacture products used in glaucoma management.