Abstract
Purpose :
To examine associations between frequency of salt usage and glaucoma-related outcomes in participants of the Thessaloniki Eye Study (TES) with and without antihypertensive medication use.
Methods :
The study population included clinic visit participants of the TES incidence phase of the investigation. Frequency of salt usage was measured by self-report and categorized as: never, occasional, or frequent usage during meals and while cooking. Outcomes examined were: intraocular pressure (IOP), visual field mean deviation (MD), cup-to-disc ratio (CDR), and prevalence of any open angle glaucoma (OAG), primary open angle glaucoma (POAG), POAG suspect, pseudoexfoliation glaucoma (PEXG), and pseudoexfoliation syndrome (PEX). Covariates included: age, gender, marital status, cardiovascular disease, migraines, steroid use, smoking status, central corneal thickness, and diastolic perfusion pressure. Associations between frequency of salt usage and each outcome were assessed in those with and without antihypertensive use using logistic regression for categorical outcomes and linear regression for continuous outcomes, adjusting for all study covariates.
Results :
Of 759 total participants, 545 (71.8%) used antihypertensives. Of all participants, 73 (9.6%) had OAG. Of participants without PEX, 38/534 (7.1%) had POAG and 132/496 (26.6%) were POAG suspects. Frequency of salt use was never in 253 (33.3%), occasional in 386 (50.9%), and frequent in 120 (15.8%) participants. In participants with antihypertensive use, when compared to never using salt, frequent salt usage was associated with increased likelihood of OAG (adjusted odds ratio [aOR]=2.49, 95% confidence interval [CI]=1.04, 5.97) and POAG (aOR=3.16, 95% CI=1.02, 9.75), while occasional salt usage was associated with decreased likelihood of POAG suspect (aOR=0.43, 95% CI=0.24, 0.75). There were no statistically significant associations between any frequency of salt usage and any outcome in those without antihypertensive use, or between any frequency of salt usage and PEXG or PEX.
Conclusions :
In participants of the TES incidence phase who use antihypertensives, frequent salt usage is associated with increased likelihood of OAG and POAG. While mechanisms were not examined, we hypothesize that this association is related to vascular dysregulation of the optic nerve in individuals with hypertension.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.