Analyses suggest users of calcium channel blockers had 39% higher odds of glaucoma compared with non-users, after controlling for confounders.
Calcium channel blocker use was adversely associated with the prevalence of glaucoma and optical coherence tomography (OCT)-derived inner retinal thickness, but not intraocular pressure (IOP), according to new research.1
Results from the cross-sectional analysis of more than 400,000 adults in the UK Biobank showed calcium channel blocker users had, on average, 39% higher odds of glaucoma than non-users, after controlling for multiple confounders.
“Our analyses provide further large-scale evidence supporting those previously reported associations and suggest that the adverse association between calcium channel blocker use and glaucoma risk may act via IOP-independent mechanisms,” wrote the investigative team, led by Alan Kastner, MD, MSc, Clínica Oftalmológica Pasteur.
Exploratory studies have reported an association between calcium channel blocker use and an increased risk of glaucoma. Many patients with hypertension are prescribed a calcium channel blocker, and given the global prevalence of both hypertension and glaucoma, the association may have important implications for clinical practice.2
Kastner and colleagues examined the association of calcium channel blocker use with glaucoma among UK Biobank participants. Additionally, the team analyzed the associations of calcium channel blocker use with corneal-compensated IOP and OCT-derived inner retinal thickness parameters: macular retinal nerve fiber layer (mRNFL) and macular ganglion cell–inner plexiform layer (mGCIPL) thicknesses.1
Calcium channel blocker use was assessed in the baseline UK Biobank questionnaire from 2006 – 2010 and confirmed during an interview with a trained nurse. Glaucoma cases were defined as participants with an ICD code for primary open-angle glaucoma (POAG) or unspecified glaucoma before, or up to 1 year after, the initial visit. Data analysis occurred in January 2023.
Investigators examined the association of calcium channel blocker use with glaucoma prevalence using multivariable logistic regression, adjusted for variables including age, sex, self-reported race and ethnicity, educational level, body mass index, and smoking status. To aid direct comparison, the associations with IOP, mGCIPL, and MRNFL were assessed using multivariable linear regression models adjusted for the same covariables.
A total of 427,480 adult participants were included in the study; the mean age was 58 years and 54.1% were women. Of all included participants, there were 33,175 (7.8%) calcium channel blocker users (29,508 had hypertension [89.0%]). Those with complete data for glaucoma status (n = 427,480), IOP (n = 97,100), and OCT-derived inner retinal layer thicknesses (n = 41,023) were eligible for respective analyses.
Upon analysis, in maximally adjusted regression models, the use of calcium channel blockers was associated with greater odds of glaucoma (odds ratio [OR], 1.39 [95% CI, 1.14 to 1.69]; P = .001). The analysis showed calcium channel blocker use was associated with thinner OCT-derived inner retinal parameters.
Participants reporting the use of calcium channel blocker use had thinner mGCIPL (–0.34 µm [95% CI, –0.54 to –0.15 µm]; P = .001) and mRNFL (–0.16 µm [95% CI, –0.30 to –0.02 µm]; P = .03) thicknesses, compared with non-users. Further, in maximally adjusted models, calcium channel blocker use was not associated with IOP (–0.01 mmHg [95% CI, –0.09 to 0.07 mmHg]; P = .84).
Investigators noted these findings remain consistent with other smaller population-based studies and add greater support to an adverse association between calcium channel blocker use and glaucoma, despite not having an obvious association with IOP.
“This warrants further investigation to determine whether the associations are causal and to probe potential underlying biological mechanisms,” investigators wrote.