Précis:
In a retrospective cohort study, serum vitamin D levels were not associated with rates of structural or functional loss in glaucoma patients, suggesting that low vitamin D level is not a risk factor for progression.
Purpose:
To investigate the association between serum vitamin D level and rates of functional and structural glaucomatous loss over time.
Methods:
This study included 826 eyes of 536 glaucoma or suspect patients with an average follow-up of 4.8±1.9 years. All patients had at least 1 serum vitamin D measurement, and all eyes had at least 2 reliable standard automated perimetry (SAP) tests and 2 spectral-domain optical coherence tomography (SD OCT) tests with a minimum follow-up of 6 months. Multivariable linear mixed-effects models were used to estimate the association of vitamin D level with rates of change in SAP mean deviation (MD) and OCT retinal nerve fiber layer (RNFL) thickness over time while adjusting for potential confounding factors.
Results:
Patients had an average of 3.4±1.7 SAP tests, 4.8±1.9 SD OCT tests, and 2.3±1.9 vitamin D measurements. The average serum vitamin D level was 33.9±13.2 ng/mL. Mean rates of MD and RNFL change were −0.03±0.08 dB/y and −0.68±0.64 µm/y, respectively. After controlling for confounding factors, there was no statistically significant association between mean vitamin D level and rates of MD (β=0.038, 95% CI: −0.006, 0.082, P=0.09) or RNFL loss over time (β=−0.018, 95% CI: −0.092, 0.055, P=0.62).
Conclusions:
We did not find a significant association between vitamin D level and rates of visual field or RNFL loss over time in individuals with glaucoma and glaucoma suspect patients.