OBJECTIVE: To determine the associations between demographics, medical, socioeconomic, ocular factors and adherence to topical glaucoma therapy with a view to improve compliance, delay disease progression and improve quality of life in glaucoma patients. MATERIALS AND METHODS: This was a hospital-based comparative longitudinal study of POAG patients attending University of Abuja Teaching Hospital Eye clinic Gwagwalada, FCT Nigeria. Consecutive old POAG patients were randomly grouped into A and B using simple random sampling technique. At baseline a pretested semi-structured interviewer administered questionnaire was used to assess the socio-demographics, adherence to medication and determinants of medication adherence. As a means of improving compliance all participants in both groups were counseled based on deficits noted in the questionnaire at baseline, given dosing time schedule and asked to chart eye drop instillation. However, in addition to counseling participants in group B or a reliable household member were contacted through mobile phone calls as a reminder for use of their medication throughout the study period of 6months. Adherence level of participants and effect of adherence on intraocular pressure control and central visual field defect progression were assessed at baseline, 90days and 180days.Statistical Package for Social Sciences (SPSS) software (SPSS for windows version 25.0) was used for analysis and significance level was set at the P value <0.05. xvii RESULTS: Ninety-six participants were recruited with 100% response rate over the study period. The mean age group was 53.26±12.70years with male to female ratio of 1.6:1. Majority of the participants were educated (94.80%) and of Igbo (44.80%) and Yoruba (12.50%) ethnic groups. At baseline 35.40% of the participants were adherent to medications, with intervention at 90days 81.20% and 79.20% of the participants in group A and B respectively adhered to medications while at the 180days 75.00% and 83.30% of the participants adhered to antiglaucoma medications in group A and B respectively. Significant predictors of adherence in this study were age below 40years (AOR= 5.10; 95%CI, 1.18 – 21.82; P=0.029) and the presence of co-morbidities (AOR=5.41; 95%CI, 1.64 – 17.86; P=0.009) using bivariate logistic regression. The mean IOP at baseline were 18.75±0.80mmHg and 21.30±1.01mmHg in group A and B respectively. At the 90days, the mean IOP were 15.17±0.77mmHg and 15.40±0.78mmHg while at 180days 14.71±0.77mmHg and 13.66±0.69mmHg in group A and B respectively. The observed difference in IOP control between the two groups at baseline (t-test value= -0.639, P value =0.524), at the 90days (t-test value= -0.42, P value =0.677) and at the 180days (t-test value= -1.11, P value =0.271) were not statistically significant. At 90days, participants with controlled IOP were 19% (COR= 0.81;95%CI, 0.07- 0.87; P value = 0.014) and 62% (COR= 0.38; 95% CI, 0.06 – 1.15; P value =0.075) less likely to have adhered to medications when compared to those with uncontrolled IOP in group A and B respectively. At the 180days, participants with controlled IOP were 30% (COR= 0.70; 95%CI, 0.08 - 0.71; P value = 0.048) and 83% (COR= 0.17; 95%CI, 0.04 - 1.22; P value = 0.094) less likely to have adhered to medications when compared to those with uncontrolled IOP in group A and B respectively. xviii At the 90days, participants with no progression on CVF analysis were 4.5 times (COR= 4.50; 95%CI, 0.96 – 21.07; P value =0.049) and 5.8 times (COR= 5.80; 95%CI, 1.88 – 17.71; P value =0.000) more likely to have adhered to medications when compared to those with progression on CVF analysis in group A and B respectively. At the 180days, participants with no progression on CVF analysis were 5.3 times (COR= 5.30; 95%CI, 1.22 – 23.16; P value = 0.019) more likely and 67% (COR= 1.67; 95%CI, 0.36 – 7.67; P value = 0.509) less likely to have adhered to medications in group A and B respectively.