Eyeworld

EW INTERNATIONAL 82 February 2016 by Michelle Dalton EyeWorld Contributing Writer "due to patient selection criteria," Dr. Yildirim said, as the effects of aging and postmenopausal hormon- al changes were eliminated. Using Schirmer's test (especially since this study did not specify if it was with or without anesthesia) has its limitations and is not a preferred method in testing for dry eye, Dr. Epitropoulos said. "Schirmer's test for aqueous de- ficiency does not test for evaporative dry eye disease, and it's relatively insensitive for early forms of dry eye disease. You're going to miss a lot of patients that have dry eye disease by using Schirmer's," she said. Addi- tionally, future studies evaluating the hypothesis should have a much larger sample size, "along with more specific point of care testing such as tear osmolarity or inflam- matory markers, such as the MMP-9 InflammaDry test [Rapid Pathogen Screening, Sarasota, Fla.]." FSS was negatively correlated with Schirmer's test (P=0.038) and TBUT scores (P=0.002); VAS-pain was neg- atively correlated with TBUT scores (P=0.023). HAQ scores showed no significant correlation with dry eye parameters (P>0.05). Vitamin D level was negatively correlated with OSDI (P<0.001) and positively with Schirmer's test (P=0.001) and TBUT scores (P=0.029). "Impaired tear function tests may indicate a pathophysiologi- cal association between vitamin D deficiency and dry eye," the authors wrote. Not a bullseye Serum 25 D3 levels were not found to be associated with the severity of dry eye in a recent cross-sectional study on males with dry eye disease. 2 Because the current study included only premenopausal women, that may be seen as a deficit, or simply in assisting with the inflammatory mediators in the tear film in patients suffering with dry eye," Dr. Epitropoulos said. Study details Fifty premenopausal women with vitamin D deficiency and 48 con- trols were included. Participants were assessed by Schirmer's test, tear break-up time test (TBUT), Ocular Surface Disease Index (OSDI), Stanford Health Assessment Ques- tionnaire (HAQ), fatigue severity scale (FSS), and visual analogue scale-pain (VAS-pain). Of the women with vitamin D deficiency, 52% (26 patients), 74% (37 patients), and 70% (35 patients) had dry eye according to the results of Schirmer's test, TBUT, and OSDI, respectively. Lower scores in Schirmer's test and TBUT and higher scores in OSDI were detected in patients with vitamin D defi- ciency than in controls (P<0.05). New research from Turkey suggests there is V itamin D, a fat-soluble vitamin produced in the skin following exposure to sunlight, may be protec- tive against the develop- ment of dry eye disease, according to a group of researchers from Turkey. Pelin Yildirim, MD, Kocaeli Derince Training and Research Hos- pital, Kocaeli, Turkey, and colleagues noted vitamin D deficiency (a serum 25-hydroxyvitamin D level of less than 20 ng/mL) has been linked to numerous health problems, includ- ing type 2 diabetes, hypertension, and cardiovascular disease, and optic neuritis and myopia. But to date, there "is no data" about the relation- ship, if any, "between vitamin D de- ficiency and dry eye and the clinical parameters of both pathologies," Dr. Yildirim and co-authors said. 1 Numerous studies have correlated vitamin D3 deficiency and other inflammatory diseases, including dry eye studies, said Alice Epitropoulos, MD, clinical assistant professor, Ohio State University, Columbus, and cofounder, the Eye Center of Columbus. "This was the first study (while small—there was only 50 healthy women enrolled) that made no other inflammatory correlation within the study group and specifi- cally measured clinical signs of dry eye in a deficient population against a non-deficient control," she said. Other studies have evaluated the im- munomodulatory role of vitamin D; in vivo studies (animal models) have shown vitamin D to be anti-inflam- matory at the ocular surface, and in vitro vitamin D can lessen the inflammatory response to infection. Since the underlying cause of dry eye is inflammation, it makes sense that there could be an associ- ation between vitamin D deficiency and the disease, Dr. Epitropoulos said. Other studies have reported that "vitamin D3 induces production of IL-10, which inhibits production of other pro-inflammatory cytokines, including IL-1, IL-6 and TNF-alpha. It makes physiological sense that vitamin D3 would also play a role Vitamin D and dry eye: Is there an association? The TearLab Osmolarity System tests for hyperosmolarity in the tear film, a hallmark of dry eye disease. Source: Alice Epitropoulos, MD

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