The aim of the study was to identify adherence and predicting factors for non-adherence and to assess the association of adherence with patient satisfaction of glaucoma therapy. METHODS: The study population included 1,046 glaucoma outpatients with less than two years of drug use recruited at15 eye clinics from March to November 2013.  All patients completed a self-administered questionnaire asking about their daily use of glaucoma medications to estimate adherence and patients’ baseline characteristics to examine predicting factors for non-adherence. Adherence was defined as patients administering the drug for ≥90% of prescribed days. Patient satisfaction was also measured using the 14-item Treatment Satisfaction Questionnaire for Medication (TSQM) questionnaire which provided scores on four sub-scales: medication effectiveness, side effects, convenience and global satisfaction. The scores on TSQM are ranged 0 to 100 where higher scores indicate better satisfaction. RESULTS: Of 1,046 patients, 71.1%showed to be adherent to their glaucoma therapy while 28.9% accounting for 298 number of patients remained non-adherent. The predicting factors for non-adherence were found to be patients age <65 years, and employed (p<0.05). Non-adherent patients showed less satisfactory to treatment than adherent patients as displayed by relatively lower scores in all sub-scales on TSQM. In the scores on the TSQM, the largest difference between non-adherent and adherent patients was observed on medication effectiveness (26.07±12.21 vs. 59.21±14.27, p<0.001) and the smallest difference was detected in side effects (89.53±18.00 vs. 90.50±16.46, p=0.405). CONCLUSIONS:

About one third of the study population were non-adherent, and age and employment status were shown to influence non-adherence. Patient satisfaction was significantly associated with adherence given the lower scores on TSQM in non-adherent patients. Thus, these findings should be taken into account in decision making process for glaucoma treatment.