The results of a meta-analysis published in the journal Acta Ophthalmologica 2020 show an association between vitamin D deficiency and dry eye syndrome. Dry eye syndrome is a multifactorial disorder characterized by a decrease in the number of tears. It causes eye discomfort, visual disturbances, tear film instability, and inflammation of the ocular surface.
This syndrome affects 5-34% of the world's population, and its prevalence increases with age. Previous studies have shown that vitamin D deficiency is associated with hyperosmolarity and tear membrane dysfunction so that vitamin D deficient patients are prone to dry eyes.
A systematic study and meta-analysis have been carried out to determine the association between serum vitamin D levels and dry eye. A systematic literature search was performed using the PubMed, Embase, Web of Sciences, and Cochrane Library databases to identify clinical trials that assessed the association between serum vitamin D levels and dry eye.
The analysis results of 10 studies (n=18,919) showed that patients with dry eyes had lower serum vitamin D levels of 3.99 ng/mL than healthy controls (95% CI -6.57 to -1.40; 0= 0.002). The mean Ocular Surface Disease Index score was higher (mean difference 10.70; 95% CI 1.55-19.86; p=0.02), and the Schirmer test result without anesthesia was lower (mean difference 6 .38 mm/5 min, 95% CI -10.48 to -2.28; p=0.002) in patients with vitamin D deficiency compared to controls. The tear breakup time was comparable between the vitamin D deficiency and the control groups (p=0.15).
This meta-analysis showed that vitamin D deficiency was associated with worse subjective symptoms and less tear production in patients with dry eye syndrome. Vitamin D deficiency can be a risk factor for dry eye syndrome.
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Reference:
1. Liu J, Dong Y, Wang Y. Vitamin D deficiency is associated with dry eye syndrome: A systematic review and meta-analysis. Acta Ophthalmologica 2020. doi: 10.1111/aos.14470
2. Demirci G, Karaman Erdur S, Ozsutcu M, Eliacik M, Olmuscelik O, Aydin R, et al. Dry eye assessment in patients with vitamin D deficiency. Eye Contact Lens 2018;44(Suppl 1):62–5.
