Salt and sugar?

Has anyone who practices self tonometry noted what the effects of higher levels of salt or sugar on IOP are? Of course, these substances are not good for overall health in the long run, but I have not noted any effect on more short term IOP (though I haven't been scrupulous about the results yet). I actually read the other day that there is less prevalence of glaucoma in diabetes (which surprises me and i need to relocate the article to verify that I read this correctly).