Vitamin D Supplementation and Dry Eye Disease

A new study published in the recent issue of Contact Lens and Anterior Eye journal found that supplementing with vitamin D (VD) may be a useful adjuvant therapy to reduce the symptoms and indicators of dry eye.

DED is a prevalent ocular illness that affects 5 to 50% of people globally, according to estimates. Common ocular discomfort symptoms in DED include:

• Dryness
• Redness
• A feeling of a foreign body
• Heaviness
• Light sensitivity
• Pain
• Discharge
• Itching
• Eye strain

Also, the vitamin that has immunomodulatory and anti-inflammatory properties is vitamin D, which was demonstrated by numerous studies to have a correlation between VD insufficiency and both the incidence and severity of dry eye disease (DED). In this meta-analysis, Zeying Chen and colleagues examined the symptoms and indicators of DED patients both before and after using VD supplements.

The effectiveness of VD supplement in patients with DED published up to January 2023 was searched using four clinical trials registry websites and ten databases:

• Clinical trials registry websites: ISRCTN, ICTRP, CT, GCP, ICH
• Databases: Cochrane, PubMed, Web of Science, Embase, Ovid, CNKI, Scopus, CSTJ, Sinomed, Wanfang

There were 8 investigations in all, comprising a total of 439 patients. In order to determine standard mean differences (SMD) for the Schirmer's test (SH test), corneal fluorescein staining scores (CFSS, Oxford Scale, 0–5), tear film break-up time (TBUT), ocular surface disease index (OSDI), lid hyperemia, and visual analogue pain scale (VAS), two reviewers independently evaluated the quality of the literature and extracted data.

The key finding of this study was that VD supplementation was found to be effective in reducing:

• Lid hyperemia (SMD −0.71, 95% CI −1.09, −0.32, p = 0.000)
• OSDI (SMD −1.10, 95% CI −1.45, −0.74, p = 0.000)
• Tear production (SMD 1.43, 95% CI 0.81, 2.05, p = 0.000)
• Tear film stability (SMD 1.19, 95% CI 0.83, 1.55, p = 0.000)

Overall, this meta-analysis suggests that VD supplementation is an effective way to reduce several of the symptoms of DED, including lid hyperemia, TBUT, and SH test. Additionally, the subjective DED symptom score, OSDI, improved. The subgroup analysis revealed that the oral version significantly improved when compared to the buccal spray and intramuscular injection.

Reference

Chen, Z., Zhang, C., Jiang, J., Ouyang, J., Zhang, D., Chen, T., Chu, Y., & Hu, K. (2024). The efficacy of vitamin D supplementation in dry eye disease: A systematic review and meta-analysis. In Contact Lens and Anterior Eye (p. 102169). Elsevier BV. https://doi.org/10.1016/j.clae.2024.102169