The Association of Serum Vitamin D Level With the Severity of Dry Eye Parameters in Primary Sjögren Syndrome.

Purpose: To analyze the relationship between serum 25(OH)D3 level and dry eye parameters in primary Sjögren syndrome (SS).

Methods: This study included 74 eyes of 74 patients diagnosed with primary SS. Dry eye parameters included tear breakup time, Schirmer I value, corneal staining score, conjunctival staining score, and Ocular Surface Disease Index. The serum concentration of 25(OH)D3 was evaluated.

Results: The mean serum 25(OH)D3 level was 20.4 ± 8.0 ng/mL. There were strong negative correlations between serum 25(OH)D3 level and corneal staining score (P < 0.001, r = -0.446) and conjunctival staining score (P < 0.001, r = -0.455). The Schirmer I value and tear breakup time showed significant positive correlations with serum 25(OH)D3 level (P = 0.038, r = 0.261 and P = 0.003, r = 0.352, respectively). The Ocular Surface Disease Index did not show any significant correlation with serum 25(OH)D3 level.

Conclusions: This study demonstrates that serum 25(OH)D3 level might be associated with dry eye severity in primary SS.