Effects of selective serotonin reuptake inhibitors on glaucoma: A nationwide population-based study

BACKGROUND Selective serotonin reuptake inhibitors (SSRIs) are one of the most commonly prescribed classes of antidepressants. Glaucoma is the second leading cause of blindness globally and iatrogenic glaucoma has been implicated across disparate medication classes. Available studies that have sought to determine the association between SSRI exposure and glaucoma have provided mixed results. The aim of the study herein was to investigate whether an association exists between SSRI exposure and glaucoma incidence. METHODS Glaucoma cases were identified from Taiwan's National Health Insurance Research Database with a new primary diagnosis of glaucoma between 1997 and 2009. The date wherein the cases were diagnosed with glaucoma was operationalized as the index date. The control group was comprised of individuals within the database who were not diagnosed with glaucoma. 15,865 glaucoma cases were compared to 77,014 sex-, age-, residence- and insurance premium-matched controls on measures of prescribed duration and dosage of SSRIs up to 365 days before index date to proxy SSRIs exposure. RESULTS Individuals receiving SSRIs were at greater risk of glaucoma incidence (OR = 1.39; 95% CI = 1.29-1.50); the foregoing increased likelihood was reduced after adjusting for confounding variables (aOR = 1.09; 95% CI = 1.00,1.18). SSRI treatment of longer duration (i.e. >365 days) and higher doses (≥1 defined daily dose) were associated with greater risk of glaucoma incidence (aOR = 1.36; 95% CI = 1.08-1.71). Subgroup analysis showed that the effect of SSRIs on glaucoma was limited to individuals younger than 65 years of age (aOR = 1.37; 95% CI = 1.25-1.50), without diabetes (aOR = 1.39; 95% CI = 1.27-1.52), without hypertension (aOR = 1.46; 95% CI = 1.31-1.63) or hypercholesterolemia (aOR = 1.35; 95% CI = 1.23-1.48). CONCLUSION Treatment with SSRIs was associated with greater risk of having a diagnosis of glaucoma, particularly in individuals with longer duration and/or higher average dose of SSRI. Our findings suggest that individuals receiving SSRIs treatment for extended periods of time and/or at relatively higher therapeutic doses should be monitored for symptoms associated with glaucoma.