Barriers to Medical Treatment of Glaucoma - Drop Resistance and Intolerance in Patients Study (DRIPS)

Background: Eye drop noncompliance is a recognised risk factor for glaucoma-related vision loss. This study seeks to quantify the factors driving noncompliance with topical therapy among glaucoma patients. Methods: This was a retrospective observational study of glaucoma patients in both private and public clinics, self-completing a 12-item Drop Resistance and Intolerance of Patients Study (DRIPS) questionnaire, categorised into compliance, adverse effects and accessibility. Results: A total of 448 patients (M:F – 225:223) with glaucoma were included in the study. Stronger compliance was significantly associated with fewer adverse effects (β=0.21, p<0.01) and greater accessibility (β=0.15, p<0.01). A greater number of drops was associated with significantly poorer compliance (β=-0.56, p<0.01) and worse adverse effects (β=-0.91, p=0.02). Greater accessibility was significantly associated with older age (β=0.30, p<0.01) and had a nearly significant association with better visual field MD scores (β=0.42, p=0.08). Age (β=-0.09, p=0.10), length of time on drops (β=0 . 05, p=0.50) and visual field MD score (β=0.21, p=0.18) were not significantly associated with compliance. Conclusion: This study of adult glaucoma patients revealed that a greater number of prescribed glaucoma drops is significantly associated with poorer patient compliance and increased adverse effects, highlighting a critical challenge in glaucoma management. While older age was associated with greater drop accessibility, overall compliance was influenced primarily by the complexity of the medication regimen rather than factors such as age, sex, disease severity, or treatment duration. These findings underscore the need for strategies to simplify treatment regimens and address adverse effects to improve patient adherence and outcomes in glaucoma care.