This is the first study to examine the association between systemic medication and primary open-angle glaucoma (POAG) across all known drugs and drug classes.
Study design
Researchers identified 6,120 POAG cases and 20,650 control cases in a large dataset of U.S. insurance claims. The POAG cohort included patients who underwent a glaucoma procedure. Patients in the control cohort underwent cataract surgery without a glaucoma diagnosis, procedure or medication.
The analysis examined the preoperative use of 1,763 prescription generic drugs from 423 classes in the Uniform System of Classification (USC). Associations between medication and POAG status were determined by logistic regression analysis.
Outcomes
Statistical tests identified 8 USC classes and 4 generic drugs statistically significantly associated with POAG. Serotonin reuptake inhibitors (SSRIs) were significantly associated with reduced risk of POAG (OR 0.70), with citalopram being the most significant medication (OR 0.66) within the class. Serotonin-norepinephrine reuptake inhibitors (SNRIs) showed a weaker but significant protective association (OR 0.71).
Calcium channel blockers (CCB) class correlated with an increased risk of disease (OR 1.26), with amlodipine carrying the strongest risk within the group (OR 1.27). Angiotensin II antagonists also had a slightly weaker, but still significant, association.
A dose-response relationship was identified for SSRIs, but not CCBs. For SSRIs, the odds of POAG reduced as days of drug supply increased.
Limitations
While this study demonstrates a significant association between the drug classes, SSRIs and CCBs, and disease, causality cannot be proven. Other environmental factors associated with POAG can correlate with comorbidities or treatments. Disease diagnosis and coding of these patients can vary among clinicians in the database and the severity was not assessed by imaging or perimetry criteria. The cohort was also restricted to patients undergoing surgery.
Clinical significance
It is important that eye care providers be aware of the potential effects of systemic medication on patients with glaucoma. This study highlights medications that can be both protective (SSRIs) and harmful (CCBs) for patients undergoing treatment for POAG. Additional studies, however, are necessary to validate these findings.