This study linked salt intake to open-angle glaucoma. Photo: Milada Vigerova  on Unsplash.

In addition to the known association between low ocular perfusion pressure and glaucoma in individuals with vs. without antihypertensive treatment, there is also the possibility that salt consumption impacts glaucoma risk. In a recent study, researchers examined the association between salt intake and glaucoma in antihypertensive users of the Thessaloniki Eye Study population.

Just over 1,000 participants were included. Salt intake frequency was self-reported, and outcomes included prevalence of open-angle glaucoma (OAG), primary open-angle glaucoma (POAG) and pseudoexfoliation (PEX). Logistic regression was used to examine the association between frequency of salt intake and glaucoma, controlling for covariates and stratified by antihypertensive use.

While there was no association between frequency of salt intake and prevalence of OAG, POAG or PEX in the overall study population, a potential association was found between more frequent dietary salt intake and increased prevalence of OAG and POAG in antihypertensive users overall and in those with diastolic blood pressure less than 90mm Hg.

“These results suggest that increased dietary salt intake may potentially be associated with detrimental effects on glaucoma risk in those with pre-existing disruption to vascular autoregulation to which salt intake may be a contribution,” the authors explained. “On the other hand, salt intake may be contributing to the initiation and onset of hypertension, which then leads to impaired vascular autoregulation. Interestingly, in our previous analyses, association of diastolic blood pressure with optic disc structure in non-glaucoma participants and of diastolic blood pressure with POAG was found only in those receiving antihypertensive treatment.”

This current finding reveals a potential role of salt intake in the same pathophysiology pathway, the authors suggested. They noted that further research should be done to evaluate the effects of salt intake on perfusion to the optic nerve and any associated glaucomatous damage.

Tseng VL, Topouzis F, Yu F, et al. Association between dietary salt intake and open angle glaucoma in the Thessaloniki Eye Study. J Glaucoma. April 27, 2022. [Epub ahead of print].