The association between glaucoma treatment adherence with disease progression and loss to follow-up

Prospective cohort study from Brazil to evaluate glaucoma treatment adherence using a medication event monitoring system (MEMS) device and correlate with glaucoma progression and loss to follow-up (LTF) after one year of follow up. We included primary open glaucoma (POAG) patients treated with at least one ocular hypotensive eye drop. MEMS devices was used to monitor adherence for 60 days and evaluate the percentage of doses prescribed taken within the 60-day period. We classified patients according to rates of adherence: low adherence (less than 75% from MEMS measurements) and high adherence (more than 75% from MEMS measurements). We applied a questionnaire to investigated self-reported behavior towards treatment behaviors (glaucoma treatment compliance assessment tool, GTCAT). We also correlated rates of treatment adherence with clinical, demographical variables and the occurrence of glaucoma progression or LTF after one year of observation. We included 110 POAG patients and found that 28.18% of them were considered low adherent. We identify several variables associated with poor adherence such as glaucoma progression, LTF, younger age, low educational and income levels, absence of health insurance, years of disease and peak intraocular pressure. Several constructs from the self-reported GTCAT were also correlated with the rates of treatment adherence. To date, this is the first study in Latin America to evaluate glaucoma treatment adherence with MEMS devices and correlate adherence rates with glaucoma progression and LTF. We found a low-adherence rate of 28.18% and several additional risk factors were statistically associated with poor adherence.