Abstract
Purpose :
Glaucoma is the leading cause of irreversible blindness in Ghana, where it affects nearly 7.7% of the population aged over 30 years and 8.5% of those aged over 40 years. Reduction of intra-ocular pressure via ocular hypotensive eye drops is the first line of treatment for glaucoma. Current estimates of adherence to this treatment in Africa were obtained through self-report, which is known to overestimate adherence. In this study, we used electronic monitors to objectively assess adherence among glaucoma patients in Ghana.
Methods :
Glaucoma patients on Timolol eye drops (N=139) were recruited from the Christian Eye Centre, Cape Coast, Ghana. These 4 questionnaires were administered at baseline: Self-Reported Adherence, Glaucoma Medication Self-Efficacy (GMSE), Eye Drop Technique Self-Efficacy (EDTSE) and Brief Illness Perception (BIP). Medication adherence was measured objectively using Medication Event Monitoring System devices (MEMS) (Aardex, Switzerland) and by self-report during a 3-month period. Adherence was computed as the percentage of days medication was used as prescribed within the 3-month monitoring period. Participants with < 75% adherence score were classified as non-adherent. The association between adherence and demographic information and medical history were assessed using chi-square tests and logistic regression. The relationship between adherence and GMSE, EDTSE and BIP scores were also determined using Pearson correlation coefficient.
Results :
Of the 139 participants, 47 (33.8%) and 107 (77.0%) were classified as non-adherent based on self-report score and objective score. Mean (±SD) adherence was 49% ± 30. Objectively-measured adherence was not significantly associated with GMSE (r = -0.065, p= 0.45), EDTSE (r = 0.119, p= 0.16) and BIP scores (r = 0.068, p= 0.43). Significant associations were observed between adherence and educational level (χ2 = 9.179, p = 0.01) and the number of systemic comorbidities (χ2 = 6.029, p = 0.049), with those without systemic comorbidities being 70.4% less likely to be adherent (p = 0.045).
Conclusions :
Non-adherence to ocular hypotensive medication is common in Ghanaian patients with glaucoma. Future work should focus on identifying the factors associated with non-adherence with a goal of assisting patients efforts to adhere with their treatment.
This is a 2021 ARVO Annual Meeting abstract.