Compliance issues in glaucoma management

Patient compliance is problematic in glaucoma primarily because the initial stages of the disease are asymptomatic and many patients frequently fail to take medications that are costly and associated with side effects. Ophthalmologists must first identify key compliance issues, find a way to measure adherence and recommend strategies to overcome these problems.

Ophthalmologists must first identify key compliance issues, find a way to measure adherence and recommend strategies to overcome these problems.

In one approach to determining the extent of compliance problems in glaucoma therapy, Paul P. Lee, MD, and colleagues identified patients with an initial national drug code (NDC) claim for latanoprost, travoprost or bimatoprost from a retail pharmacy database and followed them for 12 months.¹ Although approximately one-quarter of the population had no gaps in their refill history, about 30% had one gap, 23% had two gaps, 14% had three gaps and nearly 5% had four or more gaps of different lengths. The results showed that varying patterns of lack of compliance may require different strategies to enhance compliance.

One attempt to improve compliance is through the development of a dosing aid that reminds patients to take their drops and monitors their compliance (Travatan dosing aid [TDA], Alcon Laboratories). The dosing aid helps patients administer medication and records the number of drops taken. A study involving five physicians and 20 patients showed that over the course of 1 week, 93% of drops were administered to the patients.² Data from the TDA can be downloaded directly to a physician’s computer, allowing the doctor to appropriately counsel non-compliant patients.

Figure courtesy of E. Randy Craven, MD

Another approach to improving compliance is to switch to simpler dosing schedules such as maintaining monotherapy or administering medications twice daily instead of three times daily. Use of ophthalmic combination products can achieve both goals. During the American Glaucoma Society (AGS) meeting, Dr. Randy Craven presented results from two studies on the efficacy and safety of the 0.2% brimonidine and 0.5% timolol fixed combination product.³ Pooled data from one study demonstrated that the fixed combination product was significantly more effective than monotherapy with either brimonidine three times daily or timolol twice daily with respect to decreasing IOP at most timepoints (daily timepoints were 8:00 a.m., 10:00 a.m., 3:00 p.m. and 5:00 p.m.) over a 12-month period (Figure). Timolol-treated patients and those given the combination product had more level IOP curves compared with brimonidine-treated patients. Significantly more patients in the brimonidine group reported adverse events compared with the combination group, with half as many patients on the combination product discontinuing treatment compared with patients taking brimonidine three times daily. E. Randy Craven, MD, and colleagues also presented European data from a 12-week study on switching patients on monotherapy to either a fixed combination of brimonidine and timolol or to the two concomitant medications. Results showed a 4.2 mm Hg to 5.3 mm Hg reduction in IOP across the board. The fixed combination administered twice daily was as effective as concomitant brimonidine and timolol and there were no differences between groups with respect to safety. Collectively, the data indicate that the brimonidine-timolol combination product administered twice daily is as effective as the individual agents given concurrently and is clinically superior to monotherapy with either brimonidine three times daily or timolol twice daily. The combination product also has a better safety profile than brimonidine three times daily. Follow-up compliance studies are needed to show further therapeutic benefits of this combination product.

The researchers concluded that the implementation of treatment strategies to improve compliance might reduce the need for glaucoma surgery.

The goal in improving compliance is to improve outcomes. In glaucoma, better compliance may slow disease progression. James C. Tsai, MD, and colleagues assessed the relationship between patient compliance and risk for glaucoma surgery among 3,864 patients with POAG whose information was taken from a nationally representative, multi-managed care plan claims database.⁴ During a 2-year follow-up, 3.2% of patients required surgical intervention, either trabeculoplasty or trabeculectomy. The odds of compliant patients having glaucoma decreased with increasing health severity compared with non-compliant patients. Among the most severe group, compliant patients were approximately two times less likely to require glaucoma surgery than were non-compliant patients in the most severe glaucoma group. The researchers concluded that the implementation of treatment strategies to improve compliance might reduce the need for glaucoma surgery.

References

Lee PP, Walt JG, Chiang TH, Guckian A. A novel approach in measuring glaucoma medication persistency using a claims database. Paper presented at: Annual meeting of the American Glaucoma Society; March 3, 2006; Charleston, SC.
Friedman DS, Jampel HD, Congdon NG, Blasdale-Miller R, Quigley HA. The Travatan dosing aid accurately records when drops are dispensed. Paper presented at: Annual meeting of the American Glaucoma Society; March 3, 2006; Charleston, SC.
Craven ER, Goni F, Chou C. Efficacy and safety of the IOP-lowering fixed combination brimonidine 0.2%/timolol 0.5%. Paper presented at: Annual meeting of the American Glaucoma Society; March 3, 2006.
Tsai JC, Walt JG, Chiang TH, et al. Pharmacotherapy compliance and glaucoma surgery in patients with primary open-angle glaucoma. Paper presented at: Annual meeting of the American Glaucoma Society; March 3, 2006; Charleston, SC.