In the news: Low vitamin D status Increases Uveitis Risk; Dry Eye Symptoms Linked to Depression in Women

Low Vitamin D Increases Risk of Uveitis

Uveitis, or inflammation of the eye’s uvea, is one of the leading causes of blindness worldwide among the working age population. It is postulated that noninfectious uveitis is caused by immune dysfunction.

Vitamin D plays an important role in both the innate and adaptive immune systems. It has been shown to contribute to the etiology of T-cell–mediated auto-immune diseases for example, via upregulating type 2 anti-inflammatory T helper cells and suppressing type 1 T helper cells. Low levels of vitamin D are reported to be common in the US, and the 2015-2020 Dietary Guidelines for Americans indicate that vitamin D is a nutrient of concern.

To better understand the relationship of vitamin D status and noninfectious uveitis, researchers from Harvard Medical School and the University of Pennsylvania Departments of Ophthalmology, conducted a retrospective case-control study using data from a large health care claims database (1).

The researchers identified 558 adults who received a diagnosis of noninfectious uveitis from an eye care clinician (with receipt of a confirmatory diagnosis within 120 days of the initial diagnosis) and who had a vitamin D level measured within 1 year before the first diagnosis. Each case patient was matched with 5 controls on the basis of age, sex, race/ethnicity, and index date of diagnosis (2790 controls). Low levels of vitamin D (hypovitaminosis D) was defined as a vitamin D level ≤20 ng/mL.

Patients with normal vitamin D levels were found to have a 21% lower odds of having noninfectious uveitis than patients with low levels (P = .04). African American patients had 51% increased odds for developing uveitis. P = .004).

This is not the first report to link low vitamin D status with increased risk of uveitis. Most recently, another retrospective study reported that the odds of having uveitis were 1.92 times higher for patients with hypovitaminosis D compared to patients with normal Vitamin D levels (2).

Though investigations to date do not establish a causal effect, prospective studies are warranted to evaluate whether low vitamin D does in fact cause increased risk of uveitis, and the role of vitamin D supplementation in the prevention and treatment of this condition.

Dry Eye Symptoms Linked to Depression

In a cross sectional study of women participating in the Sjögren's International Collaborative Clinical Alliance at 9 international sites, researchers sought to better understand the relationship of patient-reported symptoms and depression in those with and without Sjögren's syndrome (3). Notably, the researchers found that symptoms rather than clinical signs were better predictors of depression.

Dry eye complaints produced a1.82-fold higher odds of having depression compared to being symptom-free (p < 0.001). In both women with or without Sjögren's, the presence of symptoms of dry eyes and/or dry mouth rather than Sjögren's itself resulted in higher odds of depression.

Additionally, complaints of specific ocular sensations were associated with a 2.25 higher odds of depression including burning sensation compared to those without complaints (p < 0.001).

One particular ocular feature of Sjögren's, a positive ocular staining score, was inversely correlated with depression.

References

1. Sobrin L, et al. Association of hypovitaminosis D with increased risk of uveitis in a large health care claims database. JAMA Ophthalmol. Epub ahead of print, April, 2018.
2. Llop SM, et al. Association of low vitamin D Levels with non-infectious uveitis and scleritis. Ocul Immunol Inflamm. Epub ahead of print, Feb, 2018.
3. Gonzales JA, et al. How Are Ocular Signs and Symptoms of Dry Eye Associated with Depression in Women with and without Sjögren's Syndrome? Am J Ophthalmol. Epub ahead of print, April, 2018.