Possible dose-dependent effect of eplerenone on intraocular pressure

PURPOSE: Intraocular pressure (IOP) is the main modifiable risk factor for glaucoma. Current therapies target the anterior outflow of aqueous humor or its production. This study aims to demonstrate eplerenone could reduce IOP through a possible posterior outflow path via retinal pigment epithelium (RPE). METHODS: In this retrospective study, IOP changes in patients undergoing eplerenone treatment were investigated. Inclusion criteria were IOP data immediately before and during treatment. Exclusion criteria included ophthalmic procedures, changes in topical glaucoma treatment, or taking systemic medications affecting IOP. After reviewing 162 charts, 41 subjects were eligible. Pearson correlation test was used to investigate the correlation between continuous IOP and eplerenone dosage. RESULTS: The mean ± SD IOP before eplerenone treatment was 14.31 ± 3.73 mmHg and decreased to 13.50 ± 4.04 mmHg; however, this was not statistically significant (P = 0.39). In subset of patients with eplerenone dose of more than 25 mg/day and baseline IOP equal to or less than 15 mmHg, the mean IOP before eplerenone treatment was 12.33 ± 2.59 mmHg and decreased to 10.33 ± 2.99, which is a trend toward IOP reduction with a 16% reduction in IOP (P = 0.055). CONCLUSION: A possible dose-dependent decrease in IOP with eplerenone provides indirect evidence for the posterior flow model and suggests the mineralocorticoid receptors (MRs) in RPE play a role in the posterior flow of aqueous humor. It can be deduced that the RPE pumps responsible for the posterior flow of aqueous humor are MR-regulated and their function can be enhanced with MR antagonists.