Vitamin D Supplementation for Patients with Dry Eye Syndrome Refractory to Conventional Treatment

The ocular surface tear film as a biomarker for systemic health

The tear film is a complex structure with rich interactions with the human body. A growing body of evidence suggests that measuring changes in protein, lipid, or other metabolite concentration in the tear film can be used to help detect disease. Particularly in the era of precision medicine, the tear film serves as a promising source of non-invasive insights into systemic health for early diagnosis and treatment. This paper analyzes the latest research in tear film biomarkers for systemic diseases. The review was conducted through PubMed and Embase databases using the PRISMA protocol and includes 54 articles. This paper first reviews the anatomy and physiology of tear film, as well as the latest proteomic analysis techniques on the tear film. We then provide a disease-by-disease review on the tear film as a biomarker including 5 articles related to Alzheimer's Disease, 10 articles related to Cancers, 1 article related to Cystic Fibrosis, 1 article related to Migraines, 4 articles related to Multiple Sclerosis, 15 articles related to Parkinson's Disease, 7 articles related to Rheumatoid Arthritis, and 11 articles related to Thyroid Disease. This paper highlights the promising results of these studies yet also reviews the challenges with limited sample sizes, reproducibility, and biological understanding of biomarkers. We conclude this paper with insights for future work to ensure clinical validity and generalizability. Ultimately, the tear film is a clinically accessible, complex structure that provides a wealth of information that may contribute to a more comprehensive understanding of systemic health.

Surge in Eye Drop Safety Concerns and Interest in Alternative Dry Eye Disease Therapy Following Eye Drop Recalls: A Cross-Sectional Google Trends Analysis

OBJECTIVES

Beginning in January 2023, numerous eye drops were recalled following reports of contamination. To investigate hesitancy in topical therapies for dry eye disease (DED), we analyzed trends in Internet search traffic for alternative DED therapies and eye drop safety concerns following initial recalls.

METHODS

Google Trends (GT) was used to measure the popularity of specific search terms during a given time period. The main GT output metric for gauging interest in a search term is the Search Volume Index (SVI). We collected worldwide SVI data for terms "dry eye vitamin," "are eye drops safe," "stop eye drops," "lipiflow," "ilux treatment," "dry eye mask," "dry eye warm compress," "omega-3 for dry eyes," "dry eye plugs," "dry eye humidifier," "itear," and "IPL dry eye" from April 24, 2022, to October 29, 2023. Statistical analysis was performed with Microsoft Excel v.16.77.1, and comparisons between groups were performed using paired t tests.

RESULTS

A significant increase in SVI was observed for most keywords. When comparing the 40-week period before and after the initial recall, 7/10 alternative DED therapies demonstrated a statistically significant surge in Internet search traffic after recall ( P < 0.05). Furthermore, 2/2 keywords pertaining to eye drop safety concerns demonstrated an increase in SVI ( P < 0.0001).

CONCLUSIONS

We identified a significant surge in Internet search activity for eye drop safety and alternative DED therapies following eye drop recalls. Public health agencies and physicians may find this information valuable while attempting to address safety concerns and navigating noncompliance of routine eye drop therapy.

Low Expression of Vitamin D Receptor in Patients With Dry Eye Disease

PURPOSE

This study aimed to compare the expression of vitamin D receptor (VDR) on the ocular surface of patients with dry eye disease (DED) and controls without ophthalmological pathologies.

METHODS

Patients with DED without previous treatment were studied and compared with healthy subjects. Ocular Surface Disease Index assessement and ocular surface cytology were performed in all patients. The immunohistochemical expression of VDR was evaluated using fully automated immunohistochemistry. The evaluation involved multiplying the percentage of nuclear-labeled cells (0-100) by their intensity (0-3), resulting in a score ranging from 0 to 300 (VDR H-score). Squamous metaplasia was morphologically evaluated using liquid-phase cytology with Papanicolaou/periodic acid-Schiff staining using Nelson's grade (scale 0-3, higher grade to higher metaplastic change).

RESULTS

Eighteen patients with DED without previous treatment and 10 healthy subjects were studied. Squamous metaplasia was observed in 74% of patients with DED, in contrast to 0% in the control group. In patients with DED, there was a lower expression of VDR than in the control group (VDR H-score: 11.2 ± 13.9 vs. 80.9 ± 56; P = 0.0001). Furthermore, an inverse correlation was observed between Nelson grade and VDR H-score ( P = 0.0001, rs = -0.71). No correlation was observed between Ocular Surface Disease Index and VDR H-score.

CONCLUSIONS

This is the first study to evaluate the VDR in patients with DED. These patients presented with a lower expression of VDR than healthy subjects. No correlation was found with more severe symptoms. Patients with DED also had a higher frequency of squamous metaplasia.

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.

The Role of Vitamin D3 in Ocular Diseases

Vitamin D3 plays a vital role in numerous physiological processes within the human body, including having a positive effect on eye health. It is renowned for its immunomodulatory, anti-inflammatory, antioxidant, and angiogenic properties. Its deficiency is evolving into a significant global challenge. In order to explain the connection between vitamin D3 and various ocular diseases, 84 relevant studies, mainly from the PubMed database, published in English between 1999 and 2024 were analyzed. Ocular tissues can activate and regulate vitamin D levels, which emphasizes the significance of this nutrient in maintaining eye homeostasis. While there is suggestive evidence for a probable association between vitamin D3 and ocular health, more robust research is needed to establish causation and inform clinical guidelines.

Safety and Efficacy of Topical Vitamin D in the Management of Dry Eye Disease Associated With Meibomian Gland Dysfunction: A Placebo-Controlled Double-Blind Randomized Controlled Trial

PURPOSE

The aim of this study was to investigate the safety and efficacy of topical vitamin D in the management of dry eye disease associated with meibomian gland dysfunction (MGD).

METHODS

In this randomized controlled trial, patients with symptomatic MGD were divided into 2 groups to receive topical vitamin D drops or placebo in their randomized eyes. The exclusion criteria consisted of patients with vitamin D deficiency, previous ocular surgery, and patients with ocular diseases affecting the tear film. Patients and researchers were masked to the study groups. The outcomes included the score of Dry Eye Questionnaire (DEQ) 5 and Ocular Surface Disease Index (OSDI), corneal and conjunctival staining score, tear breakup time (TBUT), Schirmer, and MG expressibility score evaluated at baseline and weeks 4 and 8.

RESULTS

Twenty-eight eyes of 28 patients were recruited in each group. In addition to the improvement of subjective parameters in both groups, there was a statistically significantly greater improvement in the vitamin D group compared with control for average scores of OSDI (13.38 ± 7.32 vs. 27.94 ± 7.49) and DEQ5 (9.67 ± 1.86 vs. 14.14 ± 2.45) at week 8 (Ps <0.001). In addition, a significant improvement in TBUT and Schirmer test was observed in both groups in weeks 4 and 8 ( P value <0.05). There was a significant difference between the treatment and control groups after 8 weeks for OSDI, DEQ5, Schirmer, TBUT, corneal fluorescein staining, and MG expressibility score ( P value <0.05).

CONCLUSIONS

The preliminary results of this randomized controlled trial suggested that use of topical vitamin D drops with a lipid vehicle could be safe and might significantly improve the symptoms and signs of dry eye associated with MGD.

Association between systemic medication use and severity of dry eye signs and symptoms in the DRy eye assessment and management (DREAM) study

PURPOSE

Some systemic medications are reported to be associated with dry eye disease (DED), yet their associations with the severity of DED signs and symptoms are not well studied. To evaluate these associations, we performed a secondary analysis of data from the DRy Eye Assessment and Management (DREAM) Study.

METHODS

Participants (N = 535) were assessed for DED signs using tear break-up time (TBUT), Schirmer testing, corneal fluorescein staining, conjunctival lissamine green staining, meibomian gland dysfunction (MGD), and tear osmolarity and DED symptoms using the Ocular Surface Disease Index (OSDI). We derived a composite signs severity score from the 6 DED signs and categorized participant-reported systemic medications into antidepressants, antihistamines, aspirin, corticosteroids, diuretics, nonsteroidal anti-inflammatory drugs, proton pump inhibitors, statins, vitamin D3, and medications for diabetes mellitus, hypertension, hypothyroidism, migraine, and seizure. Generalized linear models were used to compare DED symptom and sign scores between medication users and non-users, with adjustment for factors associated with DED severity.

RESULTS

Compared to non-users, antihistamine users had lower TBUT (p = 0.01) and higher OSDI score (p = 0.02); aspirin users had lower TBUT (p = 0.02); corticosteroid users had lower TBUT (p = 0.02), lower Schirmer test scores (p = 0.03), higher cornea fluorescein staining (p = 0.01), higher composite severity score (p = 0.01), and higher OSDI score (p = 0.03); seizure medication users had higher composite severity score (p = 0.02); vitamin D3 users had lower TBUT (p = 0.001) and greater MGD (p = 0.03); and diuretic users had less MGD (p = 0.03).

CONCLUSIONS

Certain systemic medications may be associated with more severe DED. This may guide prescription practices in patients with DED.

Effects of dietary imbalances of micro- and macronutrients on the ocular microbiome and its implications in dry eye disease

Dry eye disease (DED) is a complex and multifactorial ocular surface disease affecting a large proportion of the population. There is emerging evidence of the impact of the microbiomes of the ocular surface and gut on the symptoms of DED, with many parallels being drawn to inflammatory diseases of other organ systems. A key factor involved in the promotion of healthy microbiomes, and which has been associated with ocular surface disease, is micro- and macronutrient deficiency. A comprehensive review of how these deficiencies can contribute to DED is absent from the literature. This review reports the composition of healthy ocular and gut microbiomes, and how nutrient deficiencies may impact these floral populations, with linkage to the subsequent impact on ocular health. The review highlights that vitamin B1 and iron are linked to reduced levels of butyrate, a fatty acid implicated in inflammatory conditions such as ulcerative colitis which itself is a condition known to be associated with ocular surface diseases. Vitamin B12 has been shown to have a role in maintaining gut microbial eubiosis and has been linked to the severity of dry eye symptoms. Similar beneficial effects of gut microbial eubiosis were noted with vitamin A and omega-3 polyunsaturated fatty acids. Selenium and calcium have complex interactions with the gut microbiome and have both been implicated in the development of thyroid orbitopathy. Further, diabetes mellitus is associated with ocular surface diseases and changes in the ocular microbiome. A better understanding of how changes in both the gut and eye microbiome impact DED could allow for an improved understanding of DED pathophysiology and the development of new, effective treatment strategies.

TFOS Lifestyle: Impact of nutrition on the ocular surface

Nutrients, required by human bodies to perform life-sustaining functions, are obtained from the diet. They are broadly classified into macronutrients (carbohydrates, lipids, and proteins), micronutrients (vitamins and minerals) and water. All nutrients serve as a source of energy, provide structural support to the body and/or regulate the chemical processes of the body. Food and drinks also consist of non-nutrients that may be beneficial (e.g., antioxidants) or harmful (e.g., dyes or preservatives added to processed foods) to the body and the ocular surface. There is also a complex interplay between systemic disorders and an individual's nutritional status. Changes in the gut microbiome may lead to alterations at the ocular surface. Poor nutrition may exacerbate select systemic conditions. Similarly, certain systemic conditions may affect the uptake, processing and distribution of nutrients by the body. These disorders may lead to deficiencies in micro- and macro-nutrients that are important in maintaining ocular surface health. Medications used to treat these conditions may also cause ocular surface changes. The prevalence of nutrition-related chronic diseases is climbing worldwide. This report sought to review the evidence supporting the impact of nutrition on the ocular surface, either directly or as a consequence of the chronic diseases that result. To address a key question, a systematic review investigated the effects of intentional food restriction on ocular surface health; of the 25 included studies, most investigated Ramadan fasting (56%), followed by bariatric surgery (16%), anorexia nervosa (16%), but none were judged to be of high quality, with no randomized-controlled trials.

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.

Conjunctival Histopathological Changes in Children With Vitamin D Deficiency

PURPOSE

The aim of this study was to investigate tear function-associated clinical findings and conjunctival histopathological changes in children with vitamin D (Vit-D) deficiency.

METHODS

This study used a prospective case-control design. Group 1 (n=38) comprised pediatric patients with Vit-D deficiency, and group 2 (n=45) was the control group. Tear break-up times (TBUTs), Schirmer-1 test measurements, ocular surface disease index (OSDI) scores, and conjunctival impression cytology (CIC) results of the groups were compared.

RESULTS

The participant demographic characteristics, including the mean age and the male-to-female ratio, were similar (P>0.05). The median TBUT and Schirmer-1 test measurement were 10 s (5-15) and 12 mm (6-19) in group 1 and 11 s (6-16) and 15 mm (8-21) in group 2 (P=0.004 and P=0.013, respectively). The median OSDI scores were 16 (10-20) in group 1 and 17 (10-21) in group 2 (P=0.092). According to the CIC, 25 samples in group 1 and 40 samples in group 2 were categorized as grade 0, 11 samples in group 1 and 5 samples in group 2 were categorized as grade 1, and 2 samples in group 1 and no sample in group 2 were categorized as grade 2 (P=0.027).

CONCLUSION

Significant conjunctival histopathological changes occur in children with Vit-D deficiency, and these changes have effects on some tear function-associated clinical findings including the Schirmer-1 test and TBUT measurements.

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.

Dry Eye Disease and Vitamins: A Narrative Literature Review

Dry eye disease (DED) is a major public health problem worldwide that seriously impairs the quality of life, reduces work productivity, and poses significant economic burden. In DED, tear film instability or hyperosmolarity activates a self-perpetuating vicious cycle that may aggravate ocular surface inflammation and damage. Thus, treatment approaches should focus on interrupting this cycle and ameliorating inflammation. In addition to anti-inflammatory medications, such as corticosteroids, cyclosporine, and lifitegrast, nutrients with anti-inflammatory and anti-oxidative properties may also be effective for the treatment of DED. Evidence indicates that vitamin deficiencies may be associated with an increased risk of DED and that vitamin supplementation can be an effective treatment for DED. In the present review, we introduce the results of clinical and experimental studies on the association between vitamin deficiencies and DED. The potential efficacy of systemic and topical supplementation in the treatment of DED is also discussed.

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.

Effect of oral vitamin D supplementation on dry eye disease patients with vitamin D deficiency

CLINICAL RELEVANCE

Dry eye disease (DED) and vitamin D deficiency are both common clinical entities. Vitamin D has been reported to play a significant role in ocular surface homeostasis.

BACKGROUND

This study aimed to determine the therapeutic effect of oral vitamin D supplementation in dry eye disease patients with vitamin D deficiency.

METHODS

A randomized, controlled study was completed in 100 patients with dry eye disease and concurrent vitamin D deficiency (< 20 ng/ml). Participants were randomly allocated to 8 weeks of oral vitamin D supplementation with both groups receiving conventional dry eye treatment with artificial tears. Schirmer's, tear break-up time (TBUT) and osmolarity tests were measured before and after eight weeks of treatment.

RESULTS

The mean age of participants was 36.8 ± 8.56 years in the treatment group (n: 50) and 34.8 ± 10.13 year in the control group (n: 50). After eight weeks of treatment the mean differences in Schirmer's, TBUT and tear osmolarity were 2.38 ± 1.55 mm, 3.95 ± 1.48 s and -16.9 ± 6.28 mOsm/L, respectively in the treatment group, and 0.7 ± 0.86 mm, 0.92 ± 1.57s and -3.34 ± 2.0 mOsm/L respectively in the control group (p < 0.001 for all parameters). The treatment group demonstrated a more significant improvement than the control group in Schirmer<apos;>s, TBUT and osmolarity values (p < 0.001).

CONCLUSION

Vitamin D supplementation as an adjuvant to routine dry eye treatment improves ocular surface hemostasis parameters, results in better tear stability and a more improved tear osmolarity in patients with vitamin D deficiency.

Association of Vitamin D deficiency with primary glaucoma among Saudi population - A pilot study

PURPOSE

Glaucoma is a complex multifactorial disorder that is influenced by various systemic conditions. Several studies investigated the association between systemic factors such as Vitamin D deficiency for glaucoma development and reported contradicted findings. The aim of this study was to assess Vitamin D levels in glaucomatous Saudi subjects and its association with cup/disc ratio in primary open- and closed-angle glaucoma.

METHODS

This was a pilot study that included subjects aged 41-78 years from both genders recruited from a tertiary hospital, Riyadh city, Kingdom of Saudi Arabia. Subjects were divided into three groups: Group 1: subjects with primary open-angle glaucoma (POAG), Group 2: subjects with primary angle-closure glaucoma (PACG), and Group 3: control subjects. All participants underwent detailed ophthalmic examinations including visual acuity, intraocular pressure measurement (IOP), gonioscopy, and fundus examinations. In addition, blood samples were collected from glaucoma patients and controls to measure the serum 25-hydroxyvitamin D levels.

RESULTS

A total of 75 subjects were included in this study. Measurement of IOP was within the range of 9-27 for all subjects. Mean serum 25-hydroxyvitamin D levels were 72.58 ± 31.79, 69.20 ± 24.24, and 67.14 ± 29.02 in Groups 1, 2, and 3, respectively. There were insignificant differences in Vitamin D levels among the three groups (P > 0.05). Moreover, no significant correlation was noted between Vitamin D levels and cup/disc ratio in Groups 1 and 2.

CONCLUSION

No association was found between Vitamin D deficiency and both POAG and PACG among Saudi population despite low serum level of Vitamin D in glaucomatous and control subjects. This study suggested that Vitamin D level may not contribute in augmenting the severity and progression of glaucoma.

Effect of vitamin D deficiency on spatial contrast sensitivity function

CLINICAL RELEVANCE

Vitamin D has regulatory effects on non-skeletal tissues including neurons. The contrast sensitivity function occurs as a result of interaction between retinal neurons.

BACKGROUND

The association between plasma vitamin D deficiency and contrast sensitivity function was investigated.

METHODS

Forty-one eyes of 41 subjects with vitamin D deficiency with plasma vitamin D level <20 ng/mL (Group 1), and 30 eyes of 30 subjects without vitamin D deficiency with plasma vitamin D level ≥20 ng/mL (Group 2), were included in this prospective study. OPTEC 6500 was used to measure the contrast sensitivity function at all spatial frequencies involving 1.5 cpd, 3 cpd, 6 cpd, 12cpd, and 18 cpd. The average and sectorial retinal nerve fibre layer thickness, the average and minimum ganglion cell-inner plexiform thickness and tear meniscus height were measured by using optical coherence tomography.

RESULTS

A significant difference was present between Group 1 and Group 2 regarding the plasma vitamin D level (12.4 ± 4.7 ng/mL in Group 1 versus 27.1 ± 6.7 ng/mL in Group 2 p < 0.001). All spatial frequencies of contrast sensitivity function were significantly greater in Group 2 than those in Group 1, as follows: 45 ± 22.6 in Group 1 versus 57.5 ± 20.9 in Group 2, p = 0.08 in 1.5cpd; 71.3 ± 31.3 in Group 1 versus 91.8 ± 27.8 in Group 2, p = 0.001 in 3cpd; 77.9 ± 39.9 in Group 1 versus 100.4 ± 38.4 in Group 2, p = 0.013 in 6cpd; 32 ± 17.5 in Group 1 versus 48.8 ± 25.2 in Group 2, p = 0.002 in 12cpd; and 12.1 ± 5 in Group 1 versus 17.5 ± 9.5 in Group 2, p = 0.001 in 18cpd. However, there were no significant difference between two groups in terms of retinal fibre layer thicknesses, ganglion cell-inner plexiform layer thicknesses, and tear meniscus height.

CONCLUSION

Vitamin D deficiency can lead to a decrease in contrast sensitivity function that is an indicator of visual quality. This may be an underlying reason for certain visual complaints.

A Review of Topical and Systemic Vitamin Supplementation in Ocular Surface Diseases

In the homeostasis of the ocular surface, vitamins play a critical role in regulating inflammatory responses and promoting cell differentiation, development and correct function. Systemic vitamin supplementation has been available for many decades; in recent years, thanks to pharmacological advancements, topical vitamin delivery has also become available in an attempt to better treat ocular surface disease (OSD) and dry eye disease (DED). In this paper, we reviewed the current evidence on the role of vitamin supplementation in OSD and DED. We originally searched the PubMed archive, inspected the references and restricted the search to pertinent papers. The body of evidence was evaluated using the amelioration of both signs and symptoms as the outcome, when available. We found that in patients with vitamin deficiency, systemic supplementation of Vitamin A is effective in treating OSD, reducing both DED signs and symptoms. Additionally, systemic supplementation of vitamin D is useful in reducing DED symptoms and increasing tear volume. Vitamin A is also effective in reducing DED signs and symptoms when administered locally. The efficacy of supplementation with other vitamins is still not fully proven. In conclusion, the inclusion of vitamins into the treatment strategies for OSD and DED allows for better treatment customization and better outcomes in these patients.

Role of Choline in Ocular Diseases

Choline is essential for maintaining the structure and function of cells in humans. Choline plays an important role in eye health and disease. It is a precursor of acetylcholine, a neurotransmitter of the parasympathetic nervous system, and it is involved in the production and secretion of tears by the lacrimal glands. It also contributes to the stability of the cells and tears on the ocular surface and is involved in retinal development and differentiation. Choline deficiency is associated with retinal hemorrhage, glaucoma, and dry eye syndrome. Choline supplementation may be effective for treating these diseases.

Anti-Inflammatory and Anti-Oxidative Synergistic Effect of Vitamin D and Nutritional Complex on Retinal Pigment Epithelial and Endothelial Cell Lines against Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a multifactorial disease of the retina featured by dysfunction of retinal pigmented epithelial (RPE) and loss of photoreceptor cells under oxidative stress and inflammatory conditions. Vitamin D and antioxidants have beneficial effects against retinal degenerative diseases, such as AMD. We investigated the impact of associating vitamin D (ND) with a nutritional antioxidant complex (Nutrof Total^®; N) on oxidative stress and inflammation-like induced conditions by H₂O₂ and LPS, respectively, in human retinal epithelial (ARPE-19) and human retinal endothelial (HREC) cells. Application of either N or ND treatments to H₂O₂-induced media in ARPE-19 cells counteracted late apoptosis, attenuated oxidative DNA damage, and increased cell proliferation. Significant reduction in the expression levels of MCP1, IL-8, and IL6 cytokines was observed following application of either N or ND treatments under LPS-induced conditions in ARPE-19 cells and in MCP-1 and IL12p70 cytokine levels in HREC cells. ND and not N revealed significant downregulation of IFNγ in ARPE-19 cells, and of IL-6 and IL-18 in HREC cells. In conclusion, adding vitamin D to Nutrof Total^® protects in a synergistic way against oxidative and inflammatory stress-induced conditions in retinal epithelial and endothelial cells.

Tear Fluid and Serum Vitamin D Concentrations in Unilateral Pterygium

SIGNIFICANCE

Vitamin D has antiangiogenic, anti-inflammatory, and antifibrotic properties, which may play an inhibitory role on pterygium formation. Vitamin D concentration was measured in few studies, and contradictory results have been reported. There is no study investigating tear fluid concentration of vitamin D in pterygium patients.

PURPOSE

This study evaluated tear fluid and serum vitamin D concentrations of pterygium patients in comparison with healthy controls.

METHODS

Thirty-five (21 male, 14 female) patients with unilateral pterygium and 25 (18 male, 7 female) healthy controls were included in this case-control study. After full ophthalmic examination, blood samples were taken, and basal tear fluid was collected using glass microcapillary tubes. Tear fluid and serum vitamin D concentrations were analyzed using enzyme-linked immunosorbent assay and analyzed statistically.

RESULTS

The mean ± standard deviation age of patients was 51.7 ± 16.7 years in the study group and 50.6 ± 18.7 years in the control group, respectively (P = .82). The mean tear fluid vitamin D concentration was statistically significantly higher than the mean serum concentration in the study groups (P < .0001). The mean tear fluid (P = .76) and serum vitamin D concentrations (P = .53) did not reveal statistically significant difference between patients and controls. There was no statistically significant difference for tear fluid vitamin D concentration between pterygium eyes and fellow eyes (P = .93). The difference in concentrations was compared within the pterygium subgroups, and it was found that the mean serum vitamin D concentration trended toward lower values as the stage of pterygium increased, and the mean tear fluid vitamin D concentration trended toward higher values as the stage of pterygium increased, although these differences were not statistically significant (all, P > .05).

CONCLUSIONS

Tear fluid and serum vitamin D concentrations do not seem to have a role in pterygium pathogenesis.

Serum vitamin D levels in patients with vernal keratoconjunctivitis and its relationship with disease severity

Purpose

To evaluate the serum vitamin D levels of patients with vernal keratoconjunctivitis (VKC)

Method

A total of 39 VKC patients (21 males and 18 females) and 32 healthy individuals (19 males and 13 females) were enrolled in this study with the mean age of 18.38 ± 8.83 and 21.6 ± 9.43, respectively. The type and the grade of VKC were identified for each patient and serum 25-hydroxyvitamin D (25(OH)D) levels of all subjects were evaluated.

Results

The patients affected by VKC had statistically significant lower 25(OH)D levels (27.64 ± 8.50 ng/mL) than healthy subjects group (35.96 ± 11.34 ng/mL) ( p = 0.001). A reverse correlation was found between the serum vitamin D levels and the severity of the VKC but it was not statistically significant ( r = −0.159, p = 0.33). Besides, there were a few cases with severe and very severe VKC (2 in grade 3 and 4 in grade 4). Patients with the mixed type of the disease had lower serum vitamin D levels in comparison to tarsal and limbal forms but the difference was not statistically significant ( p = 0.38).

Conclusion

This study shows that the patients affected by VKC have lower vitamin D levels in comparison to healthy subjects and the screening of all patients with VKC for vitamin D levels seems rational.

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.

Bandage Contact Lenses versus Deproteinized Calf Blood Extract Eye Gel for Recurrent Corneal Erosion Syndrome: A Case-Control Study

Background

The clinical efficacy of eye drops in the treatment of recurrent corneal erosion syndrome (RCES) is not satisfactory. Many studies have confirmed the positive effect of the bandage contact lens (BCL) in corneal diseases, but not many in patients with RCES. The purpose of this study is to investigate the efficacy of the BCL compared with deproteinized calf blood extract eye gel in the initial treatment of RCES.

Methods

Forty-seven patients with RCES treated in our hospital from September 2010 to September 2018 were retrospectively analyzed, including 24 cases (26 eyes) in the bandage contact lenses (BCLs) group wearing bandage contact lens and 23 cases (24 eyes) in the drug group treated with deproteinized calf blood extract eye gel. The efficacy was evaluated after 3 months of treatment, with a mean follow-up time of 21.15 ± 1.71 months in the BCL group and 20.87 ± 1.89 months in the drug group. Corneal erosion resolution, pain relief, visual acuity recovery time, recurrence and complications were observed.

Results

After 3 months of treatment, 22 eyes (22/26, 84.6%) in the BCLs group achieved complete resolution, compared with 14 eyes (14/24, 58.3%) in the drug group (P <0.05). The corneal healing time in the BCLs group was 4.77 ± 4.51 weeks, which was significantly shorter than that in the drug group (9.83 ± 5.93 weeks (P <0.01)). At 1 and 2 months after treatment, the visual analogue score (VAS) in the BCLs group (3.28 ± 1.15 at 1 month and 1.90 ± 0.77 at 2 months) decreased more significantly than that in the drug group (4.54 ± 0.89 at 1 month and 2.43 ± 0.93 at 2months, P =0.000 at 1 month and P=0.034 at 2 months). At 3 months after treatment, the mean BCVA in the BCL group (logMAR 0.03±0.08) improved more significantly than that in the drug group (logMAR 0.14±0.12,P=0.001). The complete recovery time of visual acuity was 5.46 ± 4.43 weeks in the BCLs group, compared with 10.33 ± 6.12 weeks in the drug group (P =0.003). During further follow-up, recurrence was observed in 2 eyes (2/22, 9.1%) of the BCLs group and 6 eyes (6/14, 42.8%) of the drug group. No patient in both groups developed adverse side effects.

Conclusion

Bandage contact lenses are safe and effective in the initial treatment of RCES. Compared with topical deproteinized calf blood extract eye gel, the use of BCLs can provide a higher cure rate, better pain control, faster visual recovery and lower recurrence rate.

Trial Registration

Chinese Clinical Trial Registry, ChiCTR2000031241. Registered 25 March 2020- Retrospectively registered, http://www.chictr.org.cn/edit.aspx?pid=51309andhtm=4.

Dry Eye Disease: Early Recognition with Guidance on Management and Treatment for Primary Care Family Physicians

Primary care presentations of dry eye disease (DED) are common and pose a diagnostic challenge due to the variety of symptoms and the absence of certainty for family practitioners. While there are many published articles on the topic, the 2017 Tear Film and Ocular Surface Society Dry Eye Workshop was a landmark report in distinguishing multifactorial differences. Redefined terms clarified the DED disorder. The ocular surface—the tear/air interface—is the primary refractive component of the eye, which is why DED is so significant and impacts vision. There is a high prevalence of DED in the community, ranging from 5% to 30% of people across multiple studies. Elderly patients have up to 75% increased risk of DED and receive more intensive treatment than younger age groups. DED is also more common in women than men, occurring in 9.8% of postmenopausal women. The causes of DED span defective lacrimal apparatus and systemic disorders. Despite its prevalence, up to one-half of patients with confirmed DED do not receive proper alleviating treatment. Risk factors on functional and environmental bases follow. Tools to elicit a diagnosis more confidently are outlined using the Ocular Surface Disease Index (OSDI) and the Symptom Assessment in Dry Eye questionnaires (SANDE). Lacritin, lutein, vitamin A, and balanced nutrition are essential contributors to maintaining healthy eyes with appropriate management and treatment. The authors hope that this paper will prompt a more accurate and expedient diagnosis of DED in primary care practice and an earlier recognition of specialist referrals.

Dry eye disease (DED) poses a diagnostic challenge to primary care physicians. The condition involves the tear/air interface, at the corneal (ocular) surface, where light enters the eye. Any change in light refraction affects regular sight. Symptoms of DED include itching, grittiness, foreign body sensation, redness, excessive tearing, and visual blurring, the lattermost being the most common presentation. Ultimately, the untreated disease leads to continued discomfort and visual deficit, but when severe, it can result in blindness. Up to 30% of the population suffers from DED, with the elderly, particularly women, more affected. Unfortunately, up to 50% of those affected have inadequate treatment. Questionnaires help in diagnosis. Simple office tests can indicate the severity of eye problems. Technology with smartphone photography can take high-resolution images, which are useful in education and teaching. A multitude of conditions cause DED, including blepharitis, an infection of the eyelids. Environmental risks also abound. Proper nutrition is essential in maintaining eye health. Intermittent eye symptoms are likely to be underrated by the public, by purchasing over-the-counter products such as artificial tears rather than seeking a proper medical check. Newer prescription medications are now available for DED relief before advancing to debility requiring specialist treatment.

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.

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.

Dry Eyes, Ocular Lubricants, and Use of Systemic Medications Known or Suspected to Cause Dry Eyes in Residents of Aged Care Services

Ocular issues are common, burdensome, and under-researched among residents of aged care services. This study aims to investigate the prevalence of dry eyes or use of ocular lubricants among residents, and the possible association with systemic medications known or suspected to cause dry eyes. A cross-sectional study of 383 residents of six aged care services in South Australia was conducted. Data were extracted from participants' medical histories, medication charts, and validated assessments. The main exposure was systemic medications known to cause, contribute to, or aggravate dry eyes. The primary outcome was documented dry eyes or regular administration of ocular lubricants. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between systemic medications and dry eyes/use of ocular lubricants. Dry eyes were documented for 53 (13.8%) residents and 98 (25.6%) residents were administered ocular lubricants. Overall, 116 (30.3%) residents had documented dry eyes/used ocular lubricants. Of these, half (n = 58) were taking a medication known to cause, contribute to, or aggravate dry eyes. Taking one or more medications listed as known to cause dry eyes was associated with having dry eyes/use of ocular lubricants (OR 1.83, 95% CI 1.15-2.94). In sub-analyses, no individual medication was associated with dry eyes/use of ocular lubricants. Dry eyes and use of ocular lubricants are common in residential aged care. Our hypothesis generating findings suggest the need for further research into the clinical significance of systemic medications as a possible cause of dry eyes.

A prospective study to assess the role of vitamin D individually and in combination with cyclosporine in the treatment of dry eye in patients with deficient serum 25(OH)D levels

Purpose:

To study the efficiency of vitamin D3 (buccal spray) alone and combination of vitamin D3 with cyclosporine in the treatment of dry eye disease (DED) in patients with deficient serum 25(OH)D levels.

Methods:

Around 90 patients with DED with deficient serum 25(OH)D levels were included and randomized into three groups and were given treatment for dry eye (Group A- 0.5% carboxymethylcellulose (CMC), Group B- 0.5% CMC + 2000 IU vitamin D through buccal spray, Group C- 0.5% CMC + 2000 IU vitamin D through buccal spray + 0.05% cyclosporine). The patients were followed at day-15, day-30, and day-90 for improvement in tear breakup time (TBUT) and Schirmer’s, and ocular surface disease index (OSDI) score. Improvement in serum vitamin D level was assessed at day-90. One way ANOVA test, paired t-test, and Chi-square test were used for analysis.

Results:

Group B and Group C had significantly higher in Schirmer’s test-I values as compared to Group A (P = 0.001, P < 0.001, P < 0.001 at day-15, day-30, and day-90, respectively). Significantly higher values of TBUT and mean serum vitamin D levels were obtained in Group B and Group C as compared to Group A at day-90 (P < 0.05). OSDI scores of patients significantly decreased in all three groups at all follow-up visits (P < 0.05). Overall, Group C and Group B were found statistically better than Group A. Group C showed better results than Group B but they were nonsignificant.

Conclusion:

Vitamin D supplementation leads to earlier and significant improvement in TBUT, Schirmer’s, and OSDI score in patients with vitamin D deficient DED.

The Role of Nutrition and Nutritional Supplements in Ocular Surface Diseases

Dry eye disease (DED) is a multifactorial disease of the ocular surface system whose chore mechanisms are tear film instability, inflammation, tear hyperosmolarity and epithelial damage. In recent years, novel therapies specifically targeting inflammation and oxidative stress are being investigated and used in this field. Therefore, an increasing body of evidence supporting the possible role of different micronutrients and nutraceutical products for the treatment of ocular surface diseases is now available. In the present review, we analyzed in detail the effects on ocular surface of omega-3 fatty acids, vitamins A, B12, C, D, selenium, curcumin and flavonoids. Among these, the efficacy of omega-3 fatty acid supplementation in ameliorating DED signs and symptoms is supported by robust scientific evidence. Further long-term clinical trials are warranted to confirm the safety and efficacy of the supplementation of the other micronutrients and nutraceuticals.

Dysregulated Tear Fluid Nociception-Associated Factors, Corneal Dendritic Cell Density, and Vitamin D Levels in Evaporative Dry Eye

Purpose

The purpose of this study was to study the status and association among tear-soluble factors, corneal dendritic cell density, vitamin D, and signs and symptoms in dry eye disease (DED).

Methods

A total of 33 control subjects and 47 evaporative dry eye patients were included in the study. DED diagnosis and classification was based on the 2017 Report of the Tear Film & Ocular Surface Society International Dry Eye Workshop (TFOS DEWS II). DED workup, including tear film break-up time (TBUT), Schirmer's test I (STI), corneal and conjunctival staining, ocular surface disease index (OSDI) scoring, and in vivo confocal microscopy (to assess corneal dendritic cell density [cDCD] and subbasal nerve plexus [SBNP] features) was performed in the study subjects. Tear fluid using Schirmer's strip and serum were collected from the subjects. Multiplex ELISA or single analyte ELISA was performed to measure 34 tear-soluble factors levels including vitamin D.

Results

Significantly higher OSDI discomfort score, lower TBUT, and lower STI were observed in DED patients. cDCD was significantly higher in DED patients. No significant difference was observed in SBNP features. Tear fluid IL-1β, IL-17A, MMP9, MMP10, MMP9/TIMP ratio, and VEGF-B were significantly higher in DED patients. Significantly lower tear fluid IL-2, IP-10, NPY, VEGF-A, and vitamin D was observed in DED patients. These dysregulated tear factors showed significant associations with DED signs and symptoms.

Conclusions

Altered tear fluid soluble factors with potential to modulate nociception exhibited a distinct association with ocular surface discomfort status, TBUT, STI, and cDCD. This implies a functional relationship between the various tear-soluble factors and dry eye pathogenesis, indicating new molecular targets for designing targeted therapies.

Vitamin D Enhances the Efficacy of Topical Artificial Tears in Patients With Dry Eye Disease

PURPOSE

To investigate the efficacy of topical carbomer-based lipid-containing artificial tears (CLAT) and hyaluronate (HU) in patients with dry eye disease (DED) based on serum 25-hydroxyvitamin D (25HD) levels and cholecalciferol (vitamin D) supplementation.

METHODS

A total of 116 patients with DED from June 2015 to June 2016 were included. The participants were divided into the vitamin D deficiency (VDD) group and the non-VDD group according to their serum 25HD levels. The patients determined the ways of cholecalciferol supplementation. Ocular Surface Disease Index (OSDI) score, visual analog pain scale score, lid hyperemia, tear breakup time (TBUT), corneal fluorescein staining score, and Schirmer test were compared between baseline and 2 weeks posttreatment after topical applications and between before and after cholecalciferol supplementation.

RESULTS

The OSDI and visual analog pain scale scores of both VDD and non-VDD groups decreased after application of topical CLAT and HU compared with baseline values (P < 0.05 for all, paired t test). TBUT, corneal fluorescein staining score, and lid hyperemia in the VDD group remained unaffected by topical CLAT and HU, whereas those in the non-VDD group were improved (3.2 ± 1.7 vs. 4.1 ± 2.2, 0.5 ± 0.7 vs. 0.4 ± 0.6, and 2.2 ± 0.8 vs. 1.9 ± 0.7 in the non-VDD group, P = 0.001, 0.030, and 0.012, respectively). OSDI score, TBUT, and lid margin hyperemia were improved in the intramuscular group after cholecalciferol supplementation compared with pretreatment (33.2 ± 23.2 vs. 28.5 ± 21.9, 3.5 ± 1.9 vs. 6.0 ± 2.5, and 2.2 ± 0.7 vs. 1.2 ± 0.8, P < 0.05, Wilcoxon rank test).

CONCLUSIONS

The effect of topical CLAT and HU was dependent on serum 25HD levels. Cholecalciferol supplementation enhanced the efficacy of topical treatment and may be a useful adjuvant therapy for patients with DED refractory to topical lubricants.

Osteoporosis and dry eye syndrome: A previously unappreciated association that may alert active prevention of fall

Objective

Osteoporosis is a multifactorial disease associated with inflammation and hormone imbalance. It is noteworthy that dry eye syndrome shares a similar pathophysiology with osteoporosis. Both diseases are more prevalent among the elderly and females. Dry eye syndrome can result in impaired vision, which increases the risk of fall and fracture when osteoporosis exists. In this study, we investigated whether osteoporosis is associated with an increased risk of developing dry eye syndrome.

Methods

Claims data from the National Health Insurance Research Database (NHIRD) of Taiwan were used to conduct a retrospective population-based cohort study covering the period from January 1, 2000, to December 31, 2011. Multiple logistic regression was used to determine whether osteoporosis is an independent factor in the risk of developing dry eye syndrome, with risk estimates presented in the form of odds ratios (ORs).

Results

The exclusion of patients with specific autoimmune diseases and those younger than 50 years old resulted in 42,365 patients in the osteoporosis group and 147,460 patients in the comparison group during the study period. The number of patients newly diagnosed with dry eye syndrome was 6,478 (15.29%) in the osteoporosis group and 15,396 (10.44%) in the comparison group. The crude OR of patients with osteoporosis developing dry eye syndrome was 1.55 and the 95% confidence interval (95% CI) was 1.50–1.60. After adjusting for patients’ age, sex, and underlying comorbidities, the adjusted OR was 1.26 and the 95% CI was 1.22–1.30. Subgroup analysis revealed this association in each age group and among females but not among males.

Conclusions

Our results demonstrate that osteoporosis is a risk factor for the subsequent development of dry eye syndrome. Clinicians should be aware of the early symptoms of dry eye syndrome in osteoporotic patients in order to prevent further complications.

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

Objectives

Dry eye disease (DED) is an increasingly important public health problem in Korea. Previous studies conducted in Korea have reported inconsistent results regarding the protective effects of vitamin D on DED, and these discrepancies may be related to the relatively simple questionnaire that has been used. Thus, we evaluated the association of serum vitamin D levels with DED using the ocular surface disease index (OSDI).

Methods

The present study evaluated data from participants in the Study Group for Environmental Eye Disease (2014-2015). This group included data from 752 participants, and data from 740 participants (253 men and 487 women) were analyzed in the present study. DED severity was evaluated using the OSDI.

Results

Higher serum vitamin D levels were associated with a non-significantly reduced risk of DED in the crude analysis (odds ratio [OR], 0.991; 95% confidence interval [CI], 0.971 to 1.011) and in the adjusted analysis (OR, 0.988; 95% CI, 0.966 to 1.010). In the crude analysis of no/mild DED vs. moderate/severe DED, men exhibited a decreased risk with increasing serum vitamin D levels (OR, 0.999; 95% CI, 0.950 to 1.051), while women exhibited an increased risk (OR, 1.003; 95% CI, 0.979 to 1.027). In these analyses, we found no significant associations.

Conclusions

The findings of the present study support previous reports that serum vitamin D levels are not associated with DED.

Ocular Pharmacokinetics of 25-Hydroxyvitamin D3 After Weekly Supplementation in Rabbits Using Ultra Performance Liquid Chromatography-Tandem Mass Spectrometer

BACKGROUND AND OBJECTIVES

The protective role of vitamin D supplementation has recently been shown to be present in various ocular inflammatory diseases. The oral supplementation of vitamin D may take time to achieve adequate levels in intraocular fluids. Therefore, the present study was performed to understand the ocular pharmacokinetics of 25-hydroxyvitamin D3 (25D3) in aqueous humor after weekly supplementation of 25D3 in rabbits.

METHODS

A total of 21 rabbits were fed orally with 25D3 (7.22 µg/kg/week) for 8 weeks and 9th dose was given at the end of 8 weeks. The blood and aqueous humor samples were collected from ear vein and though anterior chamber paracentesis, respectively. The serum and aqueous humor samples were spiked with deuterium labeled internal standard and were extracted using liquid extraction method. Furthermore, the samples were derivatized and 25D3 estimation was performed using ultra performance liquid chromatography-tandem mass spectrometer (UHPLC-MS/MS).

RESULTS

The 25D3 supplementation significantly increased the 25D3 levels in serum (78.5 ± 21.6 ng/ml) (mean ± SD) (p < 0.0001) and in aqueous humor (991.3 ± 180.6 pg/ml) (mean ± SD) (p < 0.0001) compared to baseline levels. The maximum concentration was achieved in serum after the 10th hour of supplementation of 1st and 9th dose, while the same was observed at the 24th hour in aqueous humor.

CONCLUSION

The oral supplementation of 25D3 was found to significantly increase 25D3 levels in aqueous humor; however, the time required to achieve 25D3 concentration in aqueous humor was higher as compared to that in serum. Therefore, weekly oral supplementation of 25D3 may have a beneficial role in ocular diseases.

Calcitriol, the Active Metabolite of Vitamin D3, Inhibits Dry Eye Related Corneal Inflammation In Vivo and In Vitro

PURPOSE

To examine the influence of topical administration of calcitriol on dry eye (DE) related corneal inflammation.

METHODS

Benzalkonium chloride (BAC, 0.2%) was applied to induce DE. Then rats were treated topically with calcitriol (10^-6μM). Tear break-up time (TBUT), fluorescein staining score, inflammatory index, and tear volume were measured. Corneal epithelium damage and corneal inflammation were examined by H&E staining or RT-qPCR. In vitro, human corneal epithelial cells (iHCEC) were cultured in hyperosmotic medium (450 mOsM) with various concentrations of calcitriol. Levels of pro-inflammatory mediators were measured by RT-qPCR or ELISA. NF-κB activation was examined by Western blotting and immunofluorescence staining.

RESULTS

Calcitriol significantly ameliorated DE symptoms, attenuating corneal inflammation. In vitro studies showed that calcitriol significantly decreased the expression of pro-inflammatory mediators in iHCECs under hyperosmotic stress, probably through inhibiting NF-κB activation.

CONCLUSION

The results suggest that calcitriol might be a potential therapeutic agent for DE.

Vitamin D Replacement Improves Tear Osmolarity in Patients with Vitamin D Deficiency

BACKGROUND

Vitamin D deficiency is a common health problem worldwide. Many parts of the human eye, including the epithelium of the cornea, lens, ciliary body, and retinal pigment epithelium, as well as the corneal endothelium, ganglion cell layer, and retinal photoreceptors, contain vitamin D receptor (VDR). Dry eye is also a common health problem. An adequate tear film is required for maintaining health and function of the eye. Tear hyperosmolarity is considered to be the cause of ocular surface inflammation, symptoms, and tissue damage. It is well-documented that vitamin D has an anti-inflammatory action. We aimed to investigate the effect of vitamin D replacement on tear osmolarity in patients with vitamin D deficiency.

METHODS

A total of 44 patients (38 females, six males, mean age:43.5 ± 12.8 years) with vitamin D deficiency currently managed by the Endocrinology and Metabolism Department of Diskapi Training and Research Hospital in Turkey were enrolled in the study. Patients were given 50,000 units of 25(OH)D₃ intramuscularly, once weekly, over a period of eight weeks. All of the patients underwent tear function osmolarity (TFO) measurement initially and eight weeks after vitamin D replacement. Demographic, anthropometric, and biochemistry data of patients were recorded.

RESULTS

The mean TFO was significantly decreased (313.7 ± 17.3 mOsm/L; 302.7 ± 14.2 mOsm/L, p<0.001) at the end of the second month; 25(OH)D₃ concentrations increased from 8.3 ± 3.5 ng/mL to 68.8 ± 22.3 ng/mL (p<0.001). The mean levels of hsCRP, FPG, P were 2.5 ± 2.5 mg/L, 5.09 ± 0.48 mmol/L, 1.06 ± 0.16 mmol/L initially, and 3.8 ± 5.9 mg/L, 5.11 ± 0.68 mg/dL, 1.09 ± 0.16 mmol/L after vitamin D replacement, respectively (p>0.05). The mean Ca level was 2.37 ± 0.07 mmol/L initially and 2.35 ± 0.07 mmol/L after vitamin D replacement (p<0.05). The change of TFO was negatively correlated with the variation of 25(OH)D₃ before and after replacement in patients with dry eye disease (r=-0.390, p=0.049).

CONCLUSIONS

As a consequence of the presence of VDR and 1α-hydroxylase in different parts of the eye, vitamin D replacement improves tear hyperosmolarity that is considered to be induced by ocular surface inflammation.

Comparison Between Botulinum Toxin A Injection and Lacrimal Punctal Plugs for the Control of Post-LASIK Dry Eye Manifestations: A Prospective Study

Introduction

Laser in situ keratomelieusis (LASIK) is one of the commonest refractive procedures performed nowadays. The dry eye problem is nearly universal in all patients after LASIK and it can be so annoying that the post-operative patient satisfaction is sometimes precluded. Conventional treatment includes the use of artificial tears. Alternative methods such as punctal plugs and botulinum toxin injection can be used for the management of post-LASIK dry eye. The aim of this study is to compare botulinum toxin injection in the orbicularis muscle to lacrimal punctal plugs for the control of post-LASIK dry eye manifestations.

Methods

This is a prospective study that included 60 patients who had LASIK eye surgery for correction of refractive errors. Patients were randomly assigned to one of three methods of dry eye management; the first method was conventional medical treatment with preservative-free tear substitutes only (group A: 20 patients = 40 eyes); the second method was intraoperative injection of botulinum toxin A (BTA) in the orbicularis muscle below the lower punctum of both eyes (group B: 20 patients = 40 eyes) and the third method was intraoperative insertion of temporary extended duration silicone punctal plugs in the lower punctum of both eyes (group C: 20 patients = 40 eyes).

Results

In the first follow-up visit after 2 weeks, the two test groups (B, C) showed a statistically significant increase in both tear film break up time (TBUT) and Schirmer test score with a decrease in the OSDI score and daily frequency of lubricants used in comparison to the control group A. These differences were maintained in the next follow-up visit but they became statistically insignificant at the 3rd and 6th post-operative months. Complications were encountered more in the punctal plug patients (60%) than in BTA patients (25%) and this difference was statistically significant.

Conclusion

The use of BTA injection to control dry eye symptoms by inducing temporary punctal ectropion is an effective method to improve patient satisfaction after LASIK eye surgery. It has higher level of patient satisfaction and fewer complications in comparison to punctal plugs or topical standard dry eye treatment.