The Relation between Serum Level of Vitamin D and Dry Eye Disease

Abstract

Purpose: To investigate the relation between serum level of vitamin D and dry eye disease. Patients and Methods: In this cross-sectional case-control study, 40 patients with dry eye disease were enrolled. Dry eye was diagnosed based on the slit lamp examination, tear meniscus height, tear break up time test, ocular surface disease index, and the results of Schirmer test. Forty age- and sex-matched healthy individuals served as controls. The serum level of vitamin D was measured and compared between patients with dry eye disease and controls. Results: The mean age was 44.92 ± 11.4 and 44.07 ± 11.29 years in the case and control groups, respectively (P = 0.739). The mean serum level of vitamin D was 21.18 ± 11.83 ng/dl in the case group and 20.54 ± 9.98 ng/dl in the control group (P = 0.793). Ocular surface disease index had a positive correlation with age (r = + 0.363, P < 0.0001), but a negative correlation with the serum level of vitamin D (r = - 0.480, P = 0.002). Other investigated variables failed to demonstrate association with the serum level of vitamin D and dry eye. Conclusion: According to the present study results, no significant association between vitamin D deficiency and dry eye was detected. However, due to relatively small sample size in the present study further studies are recommended to better investigate this subject.Key words: Dry eye; Vitamin D; Schirmer test; Tear.