Abstract
Purpose :
Glaucoma, an optic neuropathy causing vision loss, is the leading cause of irreversible blindness worldwide. Intraocular pressure (IOP) is a major modifiable risk factor for open-angle glaucoma incidence and progression, and its reduction is the only therapy proven to be efficient. We explored selected factors associated with IOP in the general adult population in Switzerland, with a focus on vitamin D.
Methods :
This is a cross-sectional analysis of the association between intraocular pressure and selected factors, including systemic vitamin D3 levels, using a multicentric population-based cohort in people of European-descent (SKIPOGH). A subset of SKIPOGH including 306 participants with available IOP and vitamin D measurements was included. IOP was measured by rebound tonometry. Plasma 25-hydroxyvitamin D3 was measured by a direct, competitive chemiluminescence immunoassay and 1,25-dihydroxyvitamin D3 by a competitive enzyme immunoassay.
Results :
Mean IOP was 13.99 mmHg (SD 3.24). In multivariable mixed linear regression models, IOP was associated negatively with plasma 1,25-(OH)2-vitamin D3 (P value = 0.006). Every unit increase in log 1,25-(OH)2-vitamin D3 (nmol/L) was associated with 1.6 ± 0.5 mm Hg lower IOP, independently of age, sex, mean systemic blood pressure, body mass index, PTH, serum calcium and phosphate levels. By contrast, 25-(OH)-Vitamin D3 was not significantly associated with IOP, although the direction of the association was the same.
Conclusions :
Intraocular pressure was associated negatively with plasma 1,25-(OH)2-vitamin D3, independently of systemic blood pressure, PTH and serum calcium, in the general adult population. The inverse association of IOP with the biologically active form of vitamin D3 is in line with animal experiments showing an IOP-lowering effect of vitamin D3. The putative protective effect of vitamin D3 on primary open-angle glaucoma should be tested in future randomized clinical trials.
This is a 2020 ARVO Annual Meeting abstract.