Factors Affecting Medication Adherence to Topical Glaucoma Therapy
In the following prospective study, the authors sought to determine the associations between medical, demographic, socioeconomic and ocular factors and adherence to topical glaucoma ocular hypotensive therapy.
They included 116 patients with ocular hypertension or open-angle glaucoma from two tertiary glaucoma services and measured adherence to ocular hypotensive therapy using an electronic dose monitor (Travatan Dosing Aid, Alcon Laboratories Inc.) and collected data at 3 months after enrollment. The authors used three different definitions of adherence: Definition 1: the proportion of days taking the prescribed number of drops within 3 hours of the prescribed dosing time; Definition 2: the proportion of days taking any drops within 3 hours of the prescribed dosing time; and Definition 3: the proportion of days taking any drops within 6 hours of the prescribed dosing time. They used univariate and multivariate models to determine the association between the three adherence definitions, medical, demographic, socioeconomic and ocular factors at 3-month follow-up. The main outcome measures for this study were risk factors for poor objective medication adherence.
Adherence, using Definition 1, Definition 2, and Definition 3, was 64%, 75%, and 80%, respectively, the study authors reported. They also noted that age, total number of other eye diseases and race were significantly associated with full treatment adherence (Definition 1), with race alone significantly predicting 11% of full treatment adherence. For Definition 2, age, income, level of education, and total number of eye diseases were significantly associated with partial adherence (3 h), again race alone significantly predicted 15% of partial adherence (any drops within 3 h). For Definition 3, race, income, level of education, and total number of other eye diseases significantly predicted partial adherence (any drops within 6 h), both race and income predicted 19% of partial treatment adherence. Moreover, they found significant differences for adherence rates between patients of European descent and those of African descent for all 3 definitions with those who were less adherent more likely to be of African descent.
In conclusion, electronic dose monitors provide important information regarding adherence to topical ocular hypotensive medications in glaucoma patients. They show low adherence in a significant number of participants. Future studies are needed to determine the reasons for these differences in health behaviors related to glaucoma treatment, which should guide treatment of poor adherence with glaucoma therapy.