Ineffective Self Drop Instillation Associated With Increased Glaucoma Progression Risk

Ineffective instillation of eye drops is associated with long-term glaucoma progression, including treatment advancement to incisional surgery, according to a study published in the Journal of Glaucoma.

Researchers conducted a retrospective, observational cohort study to evaluate the association between patient efficacy in self administering eye drops and long-term glaucoma outcomes. They included the eyes of 101 patients diagnosed with either open-angle glaucoma or ocular hypertension who were treated with topical ocular hypotensive therapy for at least 6 months. Researchers filmed patients self-instilling their eye drops, and performed masked gradings of the efficacy, safety, and efficiency of instillation. 

Efficacy was defined as successful instillation of an eye drop on the ocular surface, safety assessed avoidance of contact between the tip of the medication bottle and the ocular surface or eyelids, and efficiency referred to the number of eye drops expressed from the bottle. Investigators graded participants as “effective” or “ineffective” with respect to eye drop instillation. Successful instillation of at least 1 drop on the ocular surface resulted in an “effective” rating, while failure to do so yielded an “ineffective” rating. Researchers noted a unanimous agreement regarding efficacy among the 3 graders in over 80% of recordings.

Investigators classified 88 patients (87.1%) as “effective” at baseline. The mean follow-up was 5.1 years, and 73 of those patients (68.2%) experienced glaucoma progression or underwent incisional surgery in at least 1 eye. A significantly higher percentage of patients met the criteria for glaucoma progression or underwent incisional surgery in the “ineffective” group( 100%; n=28; P =.017, Fisher’s exact test). No differences in age, baseline IOP, or baseline retinal nerve fiber layer thickness were observed between the groups.

“The distinction between effective eye drop administration and medication adherence is clinically important as patients may report that they are taking their medications, but they may not be instilling the medication on their ocular surface,” according to the researchers. “When patients are found to have elevated IOP or disease progression, clinicians may want to observe patients self-administer their eye drops in addition to asking about medication adherence to determine next treatment options.”

Study limitations include retrospective determination of visual field and retinal nerve fiber layer measurements, a disparity in size between the 2 study groups, and a single center design.

Reference

Rajanala AP, Prager AJ, Park MS, Tanna AP. Association of the effectiveness of eye drop self-instillation and glaucoma progression. J Glaucoma. Published online January 10, 2022. doi:10.1097/IJG.0000000000001982