Background/aims This study aimed to investigate treatment patterns and medication adherence of glaucoma. It also identified key factors associated with non-adherence.

Methods It was a cross-sectional, observational study. Patients who use eye-drops for ≤2 years were recruited at 15 eye clinics from March to November 2013. Data were collected through self-administered questionnaires and medical chart review. Medication adherence was evaluated using patients’ self-report on pill count and defined as patients’ administering drug for ≥80% of prescribed days. Medication adherence rate was calculated by dividing actual number of administration from total prescribed number of administration for 7 days. Patients whose self-reported prescription was different from total daily doses of physicians' prescription were considered as non-adherent.

Results A total of 1050 patients included, and medication adherence rate was evaluated in 1046 patients whose verification of adherence was available. Of the total, 27.4% were non-adherent, and the medication adherence rates of the total, the adherent, and the non-adherent were 90.6±17.8%, 96.8±5.5% and 56.6±24.7%, respectively. The most commonly used medication was prostaglandin (PGA) alone and the second was combination of two-class (β-blocker and carbonic anhydrase inhibitor (CAI)) and three-class combination of PGA, β-blocker and CAI followed. In multivariate analysis, the risk of non-adherence was 1.466 times greater in males than in females (95% CI 1.106 to 1.943) and 1.328-fold greater as the daily number of administration was increased (95% CI 1.186 to 1.487).

Conclusion Approximately, one-third of the patients were non-adherent, and males and increased daily number of administration were associated with non-adherence. It highlights that more systematic treatment strategies should be considered for better medication adherence, leading to effective glaucoma management.