Recent findings from a study published in Contact Lens & Anterior Eye evaluated the signs and symptoms in patients with dry eye disease (DED) before and after Vitamin D (VD) supplementation.
Give me some background.
VD has anti-inflammatory and immunomodulatory properties that may influence the development of DED.
Previous studies have established a link between VD and DED, indicating that decreased serum VD in DED patients is associated with increased DED symptoms, and patients with VD deficiency (VDD) may be prone to dry eye.
Talk about the study.
In this systematic review and meta-analysis, investigators collected studies from 10 databases and four clinical trial registry websites to identify studies on the efficacy of VD supplementation in DED patients published between 2015 and January 2023.
And out of these studies?
In total, eight studies and 439 cases were included, after which reviewers independently assessed the quality of the literature to calculate:
- Mean differences (standardized mean difference [SMD]) for Schirmer’s test (SH test)
- Note: An SMD of 1.00 represented untreated controls and values above or below demonstrated the treatment effect.
- Tear film break-up time (TBUT)
- Corneal fluorescein staining scores (CFSS, Oxford Scale 0-5)
- Lid hyperemia
- Ocular Surface Disease Index (OSDI)
- Visual analog pain scale (VAS)
- VAS measures subjective pain symptoms
Findings?
The statistical analyses indicated that VD supplementation (ranging from 2,000 IU in a daily buccal spray or capsule to 200,000 IU in a single intramuscular injection) improved tear production (SMD 1.43, 95% confidence interval [CI] 0.81-2.05, p=0.000) and tear film stability (SMD 1.19, 95% CI 0.83-1.55, p=0.000).
In addition, VD supplementation reduced:
- Lid hyperemia (SMD -0.71, 95% CI -1.09 to -0.32, p=0.000)
- OSDI (SMD -1.10, 95% CI -1.45 to -0.74, p=0.000)
- VAS (SMD -0.32, 95% CI -0.47 to -0.18, p=0.600)
Anything else?
Based on subgroup analyses, investigators determined that the improvement in DED signs and symptoms was more significant with the oral form of VD than the buccal spray and intramuscular injection.
Take home.
These findings suggest that VD supplementation could be an adjuvant treatment to alleviate the signs and symptoms of dry eye, such as SH test, TBUT, lid hyperemia, and reduced OSDI score.
However: Further studies are required to determine the most efficacious administration and dosage of VD.