Dry eye in vitamin D deficiency: more than an incidental association.
OBJECTIVE
The aim of this article is two-fold: (i) to demonstrate the relation between vitamin D deficiency and dry eye and impaired tear function; and (ii) to investigate the possible associations among clinical parameters of hypovitaminosis D with dry eye parameters.


METHODS
Fifty premenopausal women with vitamin D deficiency (serum vitamin D levels < 20 ng/mL) and 48 controls were included. Participants were assessed by Schirmer's test, tear break-up time test (TBUT), ocular surface disease index (OSDI), Stanford Health Assessment Questionnaire (HAQ), fatigue severity scale (FSS), and visual analogue scale-pain (VAS-pain).


RESULTS
Lower scores in Schirmer's test and TBUT, and higher in OSDI were detected in patients with vitamin D deficiency than in controls (P < 0.05). FSS was negatively correlated with Schirmer's test (r = -0,29; P = 0.038) and TBUT scores (r = -0,43; P = 0.002); VAS-pain was negatively correlated with TBUT scores (r = -0.32; P = 0.023). HAQ scores showed no significant correlation with dry eye parameters (P > 0.05). Vitamin D level was negatively correlated with OSDI (r = -0.49; P < 0.001), and positively with Schirmer's test (r = 0.45; P = 0.001) and TBUT scores (r = 0.30; P = 0.029).


CONCLUSIONS
Dry eye and impaired tear function in patients with vitamin D deficiency may indicate a protective role of vitamin D in the development of dry eye, probably by enhancing tear film parameters and reducing ocular surface inflammation. Patients with vitamin D deficiency should be evaluated for dry eye syndromes.
Department of Physical Medicine and Rehabilitation, Kocaeli Derince Training and Research Hospital, Kocaeli, Turkey.
Pelin
P
Yildirim
Department of Physical Medicine and Rehabilitation, Basak Medical Center, Ankara, Turkey.
Yeşim
Y
Garip
Department of Ophtalmology, Kocaeli Derince Training and Research Hospital, Kocaeli, Turkey.
Ayse Aslihan
AA
Karci
Department of Physical Medicine and Rehabilitation, Kocaeli Derince Training and Research Hospital, Kocaeli, Turkey.
Tuba
T
Guler
D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003941:Diagnostic Techniques, Ophthalmological; D015352:Dry Eye Syndromes / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D005123:Eye / Q000378:metabolism*; D005260:Female; D006801:Humans; D008875:Middle Aged; D010147:Pain Measurement; D017697:Premenopause; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013666:Tears / Q000378:metabolism*; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications* / Q000175:diagnosis; D055815:Young Adult
D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D
dry eye syndromes; fatigue; pain; quality of life; vitamin D deficiency