Are Serum Vitamin D Levels Associated With Dry Eye Disease? Results From the Study Group for Environmental Eye Disease

The efficacy of vitamin D supplementation in dry eye disease: A systematic review and meta-analysis

PURPOSE

Vitamin D (VD) is a vitamin with anti-inflammatory and immunomodulatory effects. Several studies have shown that VD deficiency is associated with the incidence and severity of dry eye disease (DED) in humans. This meta-analysis compared signs and symptoms in patients with DED before and after VD supplementation.

METHODS

Ten databases (PubMed, Cochrane, Web of science, Ovid, Embase, Scopus, CNKI, CSTJ, Wanfang, Sinomed) and four clinical trials registry websites (ISRCTN, CT, ICTRP, ICH GCP) were searched for studies on the efficacy of VD supplement in patients with DED that were published up to 2023 January. A total of 8 studies with 439 cases were included. Two reviewers independently assessed the quality of the literature and extracted data to calculate standard mean differences (SMD) for the Schirmer's test (SH test), tear film break-up time (TBUT), corneal fluorescein staining scores (CFSS, Oxford Scale, 0-5), lid hyperemia, ocular surface disease index (OSDI), and visual analogue pain scale (VAS).

RESULTS

The analysis showed that VD supplementation improved tear production (SMD 1.43, 95% CI 0.81, 2.05, p = 0.000) and tear film stability (SMD 1.19, 95% CI 0.83, 1.55, p = 0.000) and reduced lid hyperemia (SMD -0.71, 95% CI -1.09, -0.32, p = 0.000) and OSDI (SMD -1.10, 95% CI -1.45, -0.74, p = 0.000), which is effective in alleviating the signs and symptoms of DED.

CONCLUSIONS

VD supplementation could be an adjuvant treatment to alleviate the signs and symptoms of dry eye in the future. However, further studies regarding its most appropriate administration and dosage need to be conducted.

Serum Vitamin D Levels and Dry Eye Disease in Postmenopausal Women: A Case-Control Study at a Tertiary Care Center in Rural Haryana

Background

Despite the high prevalence of Vitamin-D insufficiency and high susceptibility to dry eye disease (DED) in postmenopausal women (PMW), correlation between DED and Vitamin D has not been explored in PMW in any Indian study.

Aims and Objectives

To explore the correlation between serum Vitamin D levels in PMW with and without DED, in a hospital-based population in rural Haryana.

Materials and Methods

Subjective (ocular surface disease index [OSDI] questionnaire) and objective clinical tests were undertaken for DED diagnosis. 25(OH) Vitamin D was measured in serum using enzyme-linked immunosorbent assay; insufficient (10-30 ng/ml) and deficient (<10 ng/ml). Descriptive statistics were analyzed by mean ± standard deviation for continuous and frequencies for the categorical variables; Student's t-test used to find out mean difference in Vitamin D levels; P < 0.05 was considered statistically significant.

Results

One hundred and forty PMW (60.1 ± 5.32 years) were included; Group-A (Controls; no DED; n: 70); Group-B (Cases; DED diagnosed by OSDI scores; n: 70); Subgroup-B1 (clinical tests negative; n: 30) and B2 (clinical tests positive; n: 40). There was no statistically significant difference in OSDI scores between B1 and B2. Significantly lower mean Vitamin D levels were found in cases (14.36 ± 4.08 ng/ml) as compared to controls (19.19 ± 6.4 ng/ml) (P = 0.001) and in B2 (13.15 ± 3.51 ng/ml) as compared to B1 (15.57 ± 4.66 ng/ml) (P = 0.01).

Conclusion

There were significantly low levels of Vitamin-D in clinically established DED. Evaluating Vitamin D levels as a part of the dry eye workup in PMW is recommended. OSDI scores were not aligned with the clinical test scores; questionnaire-based tests alone may not be sufficient for diagnosing DED.

Dry Eye Disease: What Is the Role of Vitamin D?

Dry eye disease (DED) is a multifactorial condition resulting from reduced tear secretion from the lacrimal glands, increased tear water evaporation or the production of poor-quality tears. Such tear instability can lead to inflammation and damage of the ocular surface, as well as to abnormal nociception. Historically, tear substitutes and corticosteroids have been the bastion of DED therapy, but a substantial number of patients still suffer from residual symptoms even after being treated with traditional treatments. Aiming to find safe and effective alternative therapies, recent efforts have been focused on the role of vitamin D in the cellular physiology of the eye. Possibly because of its positive effect in modulating the immune and inflammatory responses, the systemic supplementation of vitamin D seems, indeed, to be an effective therapeutic strategy, especially, but not only, for patients affected by DED that does not respond to conventional treatments. In this context, this review focuses on the literature reporting on the pathogenesis and treatment of DED, with a special emphasis on the recent investigations reporting on the potential role of the systemic administration of vitamin D as a therapeutic approach in the management of such condition.

Association of serum 25-hydroxyvitamin D concentrations with Schirmer tear test 1 and tear film breakup time in dogs

BACKGROUND

The association between vitamin D and canine keratoconjunctivitis sicca (KCS) has not been investigated in dogs.

OBJECTIVES

To investigate the association of serum 25-hydroxyvitamin D [25(OH)D] concentrations with Schirmer tear test 1 (STT-1) and tear film breakup time (TFBUT) in dogs.

METHODS

Sixty-one clinically healthy, client-owned dogs were enrolled. STT-1 and TFBUT were measured in 122 (61dogs) and 82 (41 dogs out of total 61 dogs) eyes, respectively. Serum 25(OH)D concentrations were evaluated by quantitative chemiluminescent immunoassay. The dogs were classified into 6 groups according to the evaluations (STT-1: group 1, normal [≥ 15 mm/min] in both eyes; group 2, normal in one eye and abnormal [< 15 mm/min] in the fellow eye; group 3, abnormal in both eyes; TFBUT: group 4, normal [≥ 20 sec] in both eyes; group 5, normal in one eye and abnormal [< 20 sec] in the fellow eye; group 6, abnormal in both eyes).

RESULTS

STT-1 was positively correlated with TFBUT (p < 0.001). Among the STT-1 groups, the mean serum 25(OH)D concentration in group 1 was significantly higher than in groups 2 and 3 with positive correlation (p < 0.001). However, there were no significant differences among the TFBUT groups 4, 5, and 6.

CONCLUSIONS

In dogs, it was found that serum 25(OH)D concentrations had a greater effect on quantitative KCS than qualitative KCS. Therefore, it is considered that measurement of serum 25(OH)D concentration could be included in the diagnostic tests in canine quantitative KCS patients.

Serum Vitamin D Levels and Status in Thai Optic Neuritis Subjects: A Case-Control Study

Objective

To measure serum total vitamin D or 25-hydroxyvitamin D [25(OH)D] levels and status in immune-based optic neuritis (ON) including neuromyelitis optica spectrum disorder (NMOSD)-ON, myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD)-ON, autoimmune-ON, and idiopathic-ON and compare them with age- and sex-matched healthy controls. The secondary objective was to analyze the association between serum 25(OH)D levels and ON attack severity (nadir best-corrected visual acuity; nadir BCVA).

Materials and Methods

This was a single-center, case-control study. We enrolled 59 subjects (19 NMOSD-ON, 6 MOGAD-ON, 11 autoimmune-ON, 23 idiopathic-ON) diagnosed with acute immune-based ON (any ON attacks) over 11 years. Electronic medical records were reviewed and demographic data (age at sampling, sex, aquaporin-4 immunoglobulin (AQP4-IgG); myelin oligodendrocyte glycoprotein immunoglobulin G (MOG-IgG); other biomarkers of autoimmune disorders), ON attack severity (nadir BCVA), and serum 25(OH)D levels in the acute phase of ON were collected. Serum 25(OH)D levels of 236 age- and sex-matched healthy controls were assessed.

Results

Mean serum 25(OH)D levels were significantly lower in each group of immune-based ON compared with healthy controls (p < 0.001 for each ON group). However, mean serum 25(OH)D levels were not significantly different between four ON groups (NMOSD-ON, 20.18±5.90 ng/mL; MOGAD-ON, 23.07±4.94 ng/mL; autoimmune-ON, 21.14±5.29 ng/mL; idiopathic-ON, 19.56 ±5.12 ng/mL; p = 0.525). All immune-based ON subjects had vitamin D insufficiency or vitamin D deficiency. The prevalences of vitamin D insufficiency and vitamin D deficiency were significantly higher than in healthy controls in each ON group (both p < 0.05 in each ON group). No associations were observed between serum 25(OH)D levels and ON attack severity (nadir BCVA).

Conclusions

Thai immune-based ON subjects had lower serum 25(OH)D levels and higher prevalence of vitamin D insufficiency and vitamin D deficiency compared with age- and sex-matched healthy controls. Serum 25(OH)D levels were not associated with ON attack severity (nadir BCVA). We highly recommend that serum 25(OH)D levels be screened in all subjects with acute immune-based ON.

Vitamin D, the Vitamin D Receptor, Calcitriol Analogues and Their Link with Ocular Diseases

The global prevalence of eye diseases continues to grow, bringing with it a reduction in the activity levels and quality of life of patients, and partial or complete blindness if left untreated. As such, there is considerable interest in identifying more effective therapeutic options and preventive agents. One such agent is vitamin D, known to have a range of anti-cancer, anti-angiogenic, anti-inflammatory and anti-oxidative properties, and whose deficiency is linked to the pathogenesis of a range of cardiovascular, cancer, and inflammatory diseases. This review presents the current stage of knowledge concerning the link between vitamin D and its receptor and the occurrence of eye disease, as well as the influence of analogues of calcitriol, an active metabolite of vitamin D. Generally, patients affected by various ocular disorders have vitamin D deficiency. In addition, previous findings suggest that vitamin D modulates the course of eye diseases and may serve as a marker, and that its supplementation could mitigate some disorders. However, as these studies have some limitations, we recommend further randomized trials to clarify the link between vitamin D and its activity with eye disease.

Oral vitamin D3 supplementation for femtosecond LASIK-associated dry eye vitamin D for LASIK dry eye syndrome

PURPOSE

To assess the effect of oral vitamin D₃ supplementation in dry eye after femtosecond laser-assisted in situ keratomileusis (FS-LASIK).

SETTING

Liuzhou Worker's Hospital.

DESIGN

This prospective study included 90 patients selected between January and December in 2019, who underwent FS-LASIK operation in our hospital and had obvious symptoms indicating dry eyes 1 month after operation. The subjects were randomly divided into two groups: The experimental group (n = 45) received vitamin D3 2000 IU/D continuously for 12 weeks; the control group (n = 45) did not take vitamin D3 orally. Ocular surface disease index (OSDI), Tear breakup time (TBUT) and Schirmer's test I were evaluated premedication and 1,3,6 months after treatment. Serum vitamin D3 level and the mean concentration of cytokine IL-6, IL-17, IL-23 in t ears were also measured.

RESULTS

One month after treatment, the mean OSDI score of the experimental group (11.67 ± 8.53) was significantly lower than that of the control group (23.82 ± 13.22) (P = 0.007). TBUT (10.71 ± 1.02 s) and Schirmer I (9.36 ± 0.40 mm) of the experimental group were higher than those of the control group (7.49 ± 1.29 s and 7.51 ± 0.44 mm). The OSDI (10.25 ± 5.49) was significantly lower than those of the control group(20.22 ± 6.23) and TBUT (10.75 ± 1.09 s) and Schirmer I test value (11.34 ± 0.39 mm) of the experimental group were significantly higher than those of the control group (8.36 ± 1.23, 8.12 ± 0.50) at 3 months after treatment. There were significant differences in OSDI, TBUT (P < 0.05) and Schirmer I test value between the two groups at 6 months after treatment. Serum vitamin D₃ level was negatively correlated with OSDI score (r = - 0.90; P = 0.00) and positively correlated with Schirmer I test (r = 0.88; P = 0.00), TBUT score (r = 0.89; P = 0.00) and TMH (r = 0.80; P = 0.00). IL-17 level was shown to be significantly correlated with TBUT(r = - 0.25, P = 0.014) and Schirmer I test (r = - 0.21, P = 0.018). IL-6 level was significantly correlated with OSDI (R = 0.18, P = 0.020) and TBUT (R = 0.20, P = 0.019).

Vitamin D and Ocular Diseases: A Systematic Review

The contributory roles of vitamin D in ocular and visual health have long been discussed, with numerous studies pointing to the adverse effects of vitamin D deficiency. In this paper, we provide a systematic review of recent findings on the association between vitamin D and different ocular diseases, including myopia, age-related macular degeneration (AMD), glaucoma, diabetic retinopathy (DR), dry eye syndrome (DES), thyroid eye disease (TED), uveitis, retinoblastoma (RB), cataract, and others, from epidemiological, clinical and basic studies, and briefly discuss vitamin D metabolism in the eye. We searched two research databases for articles examining the association between vitamin D deficiency and different ocular diseases. One hundred and sixty-two studies were found. There is evidence on the association between vitamin D and myopia, AMD, DR, and DES. Overall, 17 out of 27 studies reported an association between vitamin D and AMD, while 48 out of 54 studies reported that vitamin D was associated with DR, and 25 out of 27 studies reported an association between vitamin D and DES. However, the available evidence for the association with other ocular diseases, such as glaucoma, TED, and RB, remains limited.

Vitamin D deficiency is associated with dry eye syndrome: a systematic review and meta-analysis

A systematic review and meta-analysis was conducted to determine the association between the serum vitamin D level and dry eye. A systematic literature search was performed using the PubMed, Embase, Web of Science and Cochrane Library databases to identify clinical studies evaluating the association between vitamin D levels and dry eye. The random-effect model was used to combine the results. Possible sources of heterogeneity across studies were determined by meta-regression and sensitivity analysis. Overall, 10 studies (n = 18 919) were included. Patients with dry eye had a mean serum vitamin D level that was lower than that in healthy controls by 3.99 ng/ml (95% CI -6.57, -1.40; p = 0.002). The mean Ocular Surface Disease Index score was higher (mean difference 10.70, 95% CI 1.55-19.86; p = 0.02) and Schirmer's test without anaesthesia result was lower (mean difference 6.38 mm/5 min, 95% CI -10.48, -2.28; p = 0.002) in patients with vitamin D deficiency than in controls. Tear break-up time was comparable in the vitamin D deficiency and control groups (p = 0.15). Sensitivity analyses indicated that the results obtained were robust. This meta-analysis suggested that vitamin D deficiency is associated with worse subjective symptoms and less tear production in patients with dry eye. Vitamin D deficiency may be a risk factor for dry eye syndrome. Prospective cohort and intervention studies are warranted to determine if vitamin D has a protective role in the development of dry eye.

Genistein-Calcitriol Mitigates Hyperosmotic Stress-Induced TonEBP, CFTR Dysfunction, VDR Degradation and Inflammation in Dry Eye Disease

Dry eye disease (DED) signs and symptoms are causally associated with increased ocular surface (OS) inflammation. Modulation of key regulators of aberrant OS inflammation is of interest for clinical management. We investigated the status and the potential to harness key endogenous protective factors, such as cystic fibrosis transmembrane conductance regulator (CFTR) and vitamin D receptor (VDR) in hyperosmotic stress‐associated inflammation in patients with DED and in vitro. Conjunctival impression cytology samples from control subjects (n = 11) and patients with DED (n = 15) were used to determine the status of hyperosmotic stress (TonEBP/NFAT5), inflammation (IL‐6, IL‐8, IL‐17A/F, TNFα, MMP9, and MCP1), VDR, and intracellular chloride ion (GLRX5) by quantitative polymerase chain reaction and/or immunofluorescence. Human corneal epithelial cells (HCECs) were used to study the effect of CFTR activator (genistein) and vitamin D (calcitriol) in hyperosmotic stress (HOs)‐induced response in vitro. Western blotting was used to determine the expression of these proteins, along with p‐p38. Significantly, higher expression of inflammatory factors, TonEBP, GLRX5, and reduced VDR were observed in patients with DED and in HOs‐induced HCECs in vitro. Expression of TonEBP positively correlated with expression of inflammatory genes in DED. Increased TonEBP and GLRX5 provides confirmation of osmotic stress and chloride ion imbalance in OS epithelium in DED. These along with reduced VDR suggests dysregulated OS homeostasis in DED. Combination of genistein and calcitriol reduced HOs‐induced TonEBP, inflammatory gene expression, and p‐p38, and abated VDR degradation in HCECs. Henceforth, this combination should be further explored for its relevance in the management of DED.

Association between vitamin D and dry eye disease: A systematic review and meta-analysis of observational studies

PURPOSE

A number of studies have examined the association between vitamin D and dry eye disease in different populations, but findings are inconclusive. Herein, available observational studies were systematically reviewed to elucidate the overall relationship between vitamin D and dry eye disease among adult population.

METHODS

PubMed, Scopus, Google scholar and ISI web of science databases were searched until January 2020 for studies assessing the association between vitamin D and dry eye disease. The Newcastle-Ottawa Quality Assessment Scale was used to examine the quality of each study.

RESULTS

A total of 14 studies out of 252 met the inclusion criteria and were included in this systematic review and meta-analysis. Serum 25(OH) D3 was lower in dry eye disease subjects compared to healthy ones (WMD -5.93; 95 % CI, -7.47 to -4.40; P < 0.001) with evidence of significant heterogeneity (I² = 94.6 % p < 0.001). Also, in final analysis, vitamin D correlated significantly with ocular surface disease index (Fisher's Z: -0.26; 95 % CI, -0.48 to -0.04; P = 0.018), with significant heterogeneity between studies (I² = 59.3 %, P = 0.043).

CONCLUSION

It was found that serum vitamin D had a significantly lower level in dry eye disease patients, and correlated with ocular surface disease index but no other dry eye disease parameter. The findings add to the existing literature supporting the concept that nutrition especially vitamin D plays an important role in human eye health. Prospective studies are needed to confirm this relationship.

Association Between Single Nucleotide Polymorphisms in the Vitamin D Receptor and Incidence of Dry Eye Disease in Chinese Han Population

Background

Dry eye disease (DED) is a chronic dysfunction of the ocular surface and has become an important public problem. Vitamin D receptor (VDR) gene polymorphism has been found to be associated with different kinds of diseases. The relationship between single nucleotide polymorphisms (SNPs) in the VDR gene should be studied.

Material/Methods

In the present case-control study, we investigated the association of VDR gene polymorphism with DED risk. Clinical data including age, gender, body mass index (BMI, kg/m²), smoking history, diabetes, and blood pressure were recorded. Serum 25-hydroxy vitamin D (25[OH]D) was chosen as the main parameter that reflected the level of vitamin D. We identified SNPs of VDR gene Apa-1, Bsm-1, Fok-1, and Taq-1 in both DED cases and healthy controls.

Results

A total of 124 DED cases and 135 healthy controls were included in this study. It was reported that aa in Apa-1 (OR=2.803, 95% CI, 1.350–5.820) and tt in Taq-1 (OR=0.362, 95% CI, 0.141–0.930) were associated with increased the risk of DED. Analysis of the allele frequencies of VDR gene polymorphisms among DED patients and healthy controls showed that allele differences in Apa-1 were significantly associated with higher risk.

Conclusions

SNPs of VDR gene (Apa-1 and Taq-1) were associated with the risk of DED. No significant association of Bsm-1 and Fok-1 in VDR gene demonstrated significant effect in the incidence of DED. Thus, we found that several SNPs of VDR gene could provide significant pathogenic effects in the risk of DED.