The impact of adherence and instillation proficiency of topical glaucoma medications on intraocular pressure

Background: The possible sequel of poorly controlled intraocular pressure (IOP) includes treatment failure, unnecessary medication use, and economic burden on patients with glaucoma.

Objective: To assess the impact of adherence and instillation technique on IOP control.

Methods: A cross-sectional study was conducted on 359 glaucoma patients in Menelik II Hospital from June 1 to July 31, 2015. After conducting a Q-Q analysis, multiple binary logistic analyses, linear regression analyses, and two-tailed paired t-test were conducted to compare IOP in the baseline versus current measurements.

Results: Intraocular pressure was controlled in 59.6% of the patients and was relatively well controlled during the study period (mean (M) = 17.911 mmHg, standard deviation (S) = 0.323) compared to the baseline (M = 20.866 mmHg, S = 0.383, t (358) = -6.70, p < 0.0001). A unit increase in the administration technique score resulted in a 0.272 mmHg decrease in IOP (p = 0.03). Moreover, primary angle-closure glaucoma (adjusted odds ratio (AOR) = 0.347, 95% confidence interval (CI): 0.144-0.836) and two medications (AOR = 1.869, 95% CI: 1.259-9.379) were factors affecting IOP.

Conclusion: Good instillation technique of the medications was correlated with a reduction in IOP. Consequently, regular assessment of the instillation technique and IOP should be done for better management of the disease.