Electronic compliance monitoring in glaucoma patients used to topical therapy

Purpose Individual compliance of glaucoma and ocular hypertensive patients with Brimonidine was studied with regards to total dose, dosage intervals, coverage, drug waste, attempts per application and risk factors for low compliance. Methods Thirty-eight men and 26women aged 70 ±11 years [42-89] received conventional Brimonidine vials (Alphagan®, Allergan™) equipped with a microprocessor-controlled monitoring device capable to record date and time of each eye drop application with a known detection sensitivity for eye drop applications ~ 99%. 48 glaucoma and 16 ocular hypertensive patients used to eye drop therapy for 11 ±8 years [1-35] were enrolled and randomly assigned to Brimonidine therapy b.i.d or t.i.d daily for 4 weeks. Results Electronic records revealed a mean of 1.4 applications per day (range: 0.7-2.2) for patients assigned to Brimonidine 2x daily with a mean treatment interval of 18.2 hours (range: 11.2-38.4 h). Patients on Brimonidine 3x daily showed a mean rate of 1.8 applications per day (range: 1.0-2.7) and a mean treatment interval of 12.4 h (range: 9.1-39.7 h). 10 patients ceased therapy before completing the 4 weeks period, therein 4 with side effects and 6 patients having emptied the bottle prematurely. Conclusion Almost 10 percent of the patients emptied their vial in less than 4 weeks by using more than one drop per application and thereby do need refills more often than usually calculated. Our data confirm the need for larger studies on individual compliance with topical ocular therapy in glaucoma. Electronic compliance monitoring may be a useful tool in ophthalmic practice to recognize low-compliant patients.