Correlation of vitamin D levels with tear film stability and secretion in patients with dry eye syndrome

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.

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.

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.

Potential benefits of Malva sylvestris in dry-eye disease pathology in vitro based on antioxidant, wound-healing and anti-inflammatory properties

Dry eye disease (DED) is a common chronic ocular surface disease. Available therapies are effective but often associated with side effects. This study investigates the potential of a Malva sylvestris L. flower extract and two defined preparations, a mucilage and a polyphenol rich fraction, on cells that are essential for the DED pathology. Furthermore, single compounds were isolated and characterised out of the polyphenol fraction. The M. sylvestris extract and its two fractions reduced reactive oxygen species (ROS) in an ultraviolet-induced model and promoted wound healing capacity of HCE-T cells, but only the polyphenol fraction and the flower extract exhibited significant radical scavenging activity. The flower extract and the polyphenol fraction inhibited cytokine secretion (IL-6, TNF-α, IL-8) from HCE-T cells and THP-1 cells. In contrast, the mucilage fraction led to an increase in mediator secretion. The NF-κB activity and calcium influx in THP-1 and Jurkat cells, respectively was decreased by treatment with the flower extract and the polyphenol fraction, whereas the mucilage fraction had no influence on these parameters. Moreover, the flower extract and the mucilage fraction at low concentration could stimulate meibomian gland cells' lipid accumulation. The isolated single compounds showed no effect on analysed parameters, except a coumarin derivative and malvin which showed ROS inhibition effects.

Assessment of Tear Meniscus Dimensions Using Anterior Segment Optical Coherence Tomography in Vitamin D Deficiency in a Pediatric Population

BACKGROUND

To investigate of the effect of vitamin D (Vit-D) deficiency on the tear film in children and compare it with that of healthy subjects.

METHODS

This prospective and cross-sectional study comprised 75 eyes of children who had Vit-D deficiency (Group 1) and 85 eyes of age- and gender-matched healthy children (Group 2). The tear-film break-up time (TF-BUT) and Schirmer test values, as well as the Ocular Surface Disease Index (OSDI) scores, were recorded for the participants in all groups. Measurement of the tear meniscus area (TMA) and tear meniscus height (TMH) was performed 2 times in the same day via the use of anterior segment-optical coherence tomography (AS-OCT).

RESULTS

The mean age of the participants in Group 1 was 12.42 ± 3.40 years, while in Group 2, it was 12.59 ± 2.32 years (p = 0.758). Group 1 comprised 43 females and 32 males, while Group 2 comprised 44 females and 41 males (p = 0.250). The mean TMH, TMA, and Schirmer test values were found to be significantly lower in children with Vit-D deficiency (Group 1) than in healthy children (Group 2), with p < 0.05 for all the values. It was concluded that there was no significant difference in the values for the mean TF-BUT and OSDI scores (p = 0.029 and p = 0.596, respectively).

CONCLUSION

The children with Vit-D deficiency exhibited lower TMH, TMA, and Schirmer test values. The alterations that were observed in these parameters were more prominent in the participants who had lower Vit-D levels.

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.

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.

Oxidative Stress in the Anterior Ocular Diseases: Diagnostic and Treatment

The eye is a metabolically active structure, constantly exposed to solar radiations making its structure vulnerable to the high burden of reactive oxygen species (ROS), presenting many molecular interactions. The biomolecular cascade modification is caused especially in diseases of the ocular surface, cornea, conjunctiva, uvea, and lens. In fact, the injury in the anterior segment of the eye takes its origin from the perturbation of the pro-oxidant/antioxidant balance and leads to increased oxidative damage, especially when the first line of antioxidant defence weakens with age. Furthermore, oxidative stress is related to mitochondrial dysfunction, DNA damage, lipid peroxidation, protein modification, apoptosis, and inflammation, which are involved in anterior ocular disease progression such as dry eye, keratoconus, uveitis, and cataract. The different pathologies are interconnected through various mechanisms such as inflammation, oxidative stress making the diagnostics more relevant in early stages. The end point of the molecular pathway is the release of different antioxidant biomarkers offering the potential of predictive diagnostics of the pathology. In this review, we have analysed the oxidative stress and inflammatory processes in the front of the eye to provide a better understanding of the pathomechanism, the importance of biomarkers for the diagnosis of eye diseases, and the recent treatment of anterior ocular diseases.

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 vitamin D levels with clinical spectrum of central serous chorioretinopathy patients of Indian origin

BACKGROUND

Vitamin D, a fat-soluble prohormone has been implicated in various ophthalmological diseases such as ocular inflammation, glaucoma, diabetic retinopathy and ocular angiogenesis. Many studies have shown effect of vitamin D on oxidative stress, angiogenesis and retinal circulation. However, there is definitive lack in published literature on effect of vitamin D on central serous chorioretinopathy especially in view of various epidemiological studies reporting risk of vitamin deficiency in up to 40% adult population.

OBJECTIVE

To determine serum vitamin D levels in various clinical profiles of central serous chorioretinopathy and their effect on its pathophysiology in Indian population.

DESIGN

Case control observational study METHODS: Study included 42 patients (group P) of central serous chorioretinopathy (CSCR) diagnosed with optic coherence tomography (OCT), fundus fluorescein angiography (FFA) which were further sub-grouped into acute(P1), chronic (P2) and recurrent (P3). A total of 44 age & sex-matched healthy control subjects (group C) were also included. The vitamin D levels of both groups were examined and analyzed.

RESULTS

No significant difference between the groups P and C in respect of age, gender or baseline best corrected visual acuity (P = 0.153, P = 0.123 and P = 0.08, respectively) was noted. Vitamin D levels were determined as 16.473 ± 7.307 ng/mL in group P and 34.940 ± 8.348 ng/mL in group C and difference was statistically significant(P = 0.001). There were statistically significantly more no of patient in group P (78.57%) with deficient vitamin D levels as compared to normal serum levels (4.76%) (P = 0.04). Patients in group P1(acute CSCR) and P2(Chronic CSCR) also had significant more no of subjects with deficient vitamin D levels as compared to normal serum levels (P = 0.01 and P = 0.03).

CONCLUSIONS

The low serum vitamin D levels were determined in all clinical sub-types of central serous chorioretinopathy patients which point to its possible role in the pathophysiology of the disease. There is a need for further studies to determine the changes that could occur with vitamin replacement therapy in CSCR.

Changes in Tear Meniscus Analysis of Children Who Have Type 1 Diabetes Mellitus, With and Without Vitamin D Deficiency

PURPOSE

The aim of this study was to quantitatively evaluate dry eye test parameters of pediatric patients with and without vitamin D deficiency (VDD) in type 1 diabetes mellitus.

METHODS

In this prospective cross-sectional study, the Ocular Surface Disease Index, Schirmer test, tear film breakup time, corneal staining score, and anterior segment optical coherence tomography were used to determine the dry eye test parameters of pediatric patients with type 1 diabetes mellitus (T1-DMPs) (group 1) and a healthy pediatric control group (group 2). Group 1 was divided into 2 subgroups based on their vitamin D status: group 1a, who had a VDD, and group 1b, who had vitamin D levels that were within the normal range.

RESULTS

This study compared 90 eyes of 90 pediatric T1-DMPs with 80 eyes of 80 healthy controls. The demographic characteristics of the groups were similar ( P > 0.05). The tear film breakup time, Schirmer test, corneal staining score, and values of the tear meniscus height and area were observed to have been lower in the patients in group 1a than the healthy pediatric control group, at P < 0.001. The same parameters were statistically significantly lower in the patients in group 1a when compared with group 1b ( P < 0.05 for both).

CONCLUSIONS

The tear measurements of the pediatric T1-DMPs were lower than those in the healthy pediatric control group. The accompanying VDD made this situation more pronounced.

Association of keratoconus with serum levels of 25-hydroxyvitamin D and antioxidant trace elements: A systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to summarize and compare the available evidence on the level of vitamin D and antioxidant trace elements between the keratoconus (KC) patients and healthy controls. Seven case-control studies with 830 subjects were found eligible with a systematic search using PubMed, SCOPUS, Web of Science, and EMBASE till November 21, 2021. Data were synthesized with a DerSimonian and Laird random-effects method of meta-analysis. The mean serum vitamin D level was significantly lower in the patients with KC [standardized mean difference (SMD): -0.71; P < 0.001] as compared with the control group. The mean serum vitamin D level decreased more in the progressive patients (SMD: -0.80; P = 0.016) than in the stable patients (SMD: -0.66; P < 0.001) when compared with the control group. The mean serum zinc level was found significantly lower in the patients with KC compared with the control group (SMD: -1.98; P = 0.005). Pooled analysis based on the two studies showed significantly lower mean selenium levels in the KC patients (SMD: -0.34; P = 0.003). Regular evaluation of serum vitamin D, zinc, and selenium levels among the patients with KC at disease onset and future follow-ups could be promising in predicting the progressive disease and disease severity.

Gut Microbiome and Its Influence On Ocular Surface and Ocular Surface Diseases

ABSTRACT

The gut microbiome plays a substantial immunologic and pathophysiologic role in maintaining the health of the host, and dysregulation of this dynamic ecosystem has been associated with several inflammatory conditions. Many studies have explored the influence of gut microbiota on the ocular surface and whether gut microbiota impact the pathophysiology of ophthalmic conditions. These findings have highlighted the advantages of enhancing gut microbes through probiotics, prebiotics, diet, vitamin supplementations, and fecal microbial transplant in clinical practice. The purpose of this review article was to provide an up-to-date overview of the knowledge on this topic. Further exploration of this area of research is important to help guide new therapeutic targets to develop treatment and prevention of certain ocular surface diseases.

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).

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.

Treatment of Severe Ptosis by Conjoint Fascial Sheath Suspension

Objective

To explore the role of conjoint fascial sheath (CFS) suspension in the treatment of severe ptosis.

Methods

A total of 110 patients with severe ptosis who were admitted to our hospital from May 2018 to December 2020 were included. Fifty-seven patients treated with frontalis suspension were assigned into group A, and the remaining 53 patients treated with CFS suspension were assigned into group B. The curative effect, ocular surface alterations, complications, and satisfaction in the two groups were compared.

Results

Patients in group B suffered from severe upper eyelid retraction and lid lag than those in group A, as well as more limited range of motion (ROM) (P < 0.05). The curative effect and patient satisfaction in group B were higher than those in group A (P < 0.05). Postsurgical complications in group B were fewer than those in group A (P < 0.05).

Conclusion

CFS suspension is effective in the treatment of severe ptosis.

Effects of 1,25 and 24,25 Vitamin D on Corneal Fibroblast VDR and Vitamin D Metabolizing and Catabolizing Enzymes

Purpose: To investigate the effects of 1,25-Vit D3 and 24,25-Vit D3 on corneal fibroblast expression of the vitamin D-associated enzymes CYP27B1 and CYP24A1 and the roles of the vitamin D receptor (VDR) and protein disulfide isomerase, family A, member 3 (Pdia3) in these cells.Methods: CYP24A1, CYP27B1, VDR, and Pdia3 expression in corneas was detected using immunohistochemistry. Western blotting was used to measure protein expression in human and mouse fibroblasts, including VDR KO mouse cells, treated with 1,25-Vit D3 (20 nM) and 24,25-Vit D3 (100 nM). The Pdia3 inhibitor LOC14 was used to explore the role of Pdia3 as a Vit D3 receptor in these cells.Results: CYP24A1, CYP27B1, VDR, and Pdia3 were all expressed in mouse and human corneal fibroblasts. 1,25-Vit D3 significantly increased VDR expression in human and mouse fibroblasts. 1,25-Vit D3 and 24,25-VitD3 significantly increased CYP24A1 and CYP27B1 expression level in human, VDR WT mouse, and VDR KO mouse corneal fibroblasts. CYP24A1 and CYP27B1 expression was unchanged in VDR KO mouse fibroblasts treated with 1,25-Vit D3 or 24,25-Vit D3 plus LOC14. Human fibroblast VDR, CYP24A1, and CYP27B1 expression were unaffected by LOC14.Conclusions: Vitamin D metabolic enzymes, VDR, and Pdia3 are all expressed in mouse and human corneal fibroblasts. 1,25-Vit D3 modulates fibroblast vitamin D enzymes through both the VDR and Pdia3 pathways in a species-dependent manner. 24,25-Vit D3 can increase expression of fibroblast CYP24A1 and CYP27B1 in the absence of VDR and is likely involved in fibroblast regulation independent of 1,25-Vit D3 or VDR.

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.

A Novel Integrated Active Herbal Formulation Ameliorates Dry Eye Syndrome by Inhibiting Inflammation and Oxidative Stress and Enhancing Glycosylated Phosphoproteins in Rats

Dry eye syndrome (DES) is a chronic condition of the eye with insufficient production of tears leading to inadequate lubrication of eyes. Symptoms of DES are associated with discomfort and redness of the eye, blurred vision, and tear film instability which leads to the damaged ocular surface. Inflammation and oxidative stress play a significant role in the pathogenesis of the disease. In this study, the protective effect of different doses (100 or 200 mg/kg) of a novel multi-component oral formulation of lutein/zeaxanthin, curcumin, and vitamin D3 (LCD) was evaluated using a rat model with benzalkonium chloride (BAC)-induced dry eye syndrome. The formulation was administered orally to rats for 4 weeks. We observed a significant improvement in tear volume, tear breakup time, tear film integrity, and reduction in overall inflammation in rats fed with the LCD at dose 200 mg/kg performing better than 100 mg/kg. Furthermore, the formulation helped in lowering oxidative stress by increasing antioxidant levels and restored protective tear protein levels including MUC1, MUC4, and MUC5AC with 200 mg of LCD having the most significant effect. The results strongly suggest that the combination of lutein/zeaxanthin, curcumin, and vitamin-D3 is effective in alleviating the symptoms of dry eye condition with a multi-modal mechanism of action.

Nutritional and medical food therapies for diabetic retinopathy

Diabetic retinopathy (DR) is a form of microangiopathy. Reducing oxidative stress in the mitochondria and cell membranes decreases ischemic injury and end-organ damage to the retina. New approaches are needed, which reduce the risk and improve the outcomes of DR while complementing current therapeutic approaches. Homocysteine (Hcy) elevation and oxidative stress are potential therapeutic targets in DR. Common genetic polymorphisms such as those of methylenetetrahydrofolate reductase (MTHFR), increase Hcy and DR risk and severity. Patients with DR have high incidences of deficiencies of crucial vitamins, minerals, and related compounds, which also lead to elevation of Hcy and oxidative stress. Addressing the effects of the MTHFR polymorphism and addressing comorbid deficiencies and insufficiencies reduce the impact and severity of the disease. This approach provides safe and simple strategies that support conventional care and improve outcomes. Suboptimal vitamin co-factor availability also impairs the release of neurotrophic and neuroprotective growth factors. Collectively, this accounts for variability in presentation and response of DR to conventional therapy. Fortunately, there are straightforward recommendations for addressing these issues and supporting traditional treatment plans. We have reviewed the literature for nutritional interventions that support conventional therapies to reduce disease risk and severity. Optimal combinations of vitamins B1, B2, B6, L-methylfolate, methylcobalamin (B12), C, D, natural vitamin E complex, lutein, zeaxanthin, alpha-lipoic acid, and n-acetylcysteine are identified for protecting the retina and choroid. Certain medical foods have been successfully used as therapy for retinopathy. Recommendations based on this review and our clinical experience are developed for clinicians to use to support conventional therapy for DR. DR from both type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) have similar retinal findings and responses to nutritional therapies.

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.

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.

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.

Effects of vitamin D deficiency on intraocular pressure values obtained by ocular response analyzer

PURPOSE

To compare corneal biomechanical properties measured with ocular response analyzer (ORA) and intraocular pressure (IOP) measurements in patients with vitamin D deficiency and in healthy cases.

METHODS

One hundred and twenty eyes of 120 subjects (between the ages of 19 and 78) who applied to university's outpatient clinic were evaluated: 41 lacks of vitamin D (Group 1), 39 insufficient vitamin D (Group 2) and 40 controls (Group 3). Corneal hysteresis, corneal resistance factor, Goldmann-correlated IOP and corneal compensated IOP of patients were measured by ORA.

RESULTS

The mean ages were 48.9 ± 12.1, 52.8 ± 13.6 and 52.1 ± 13.9 in groups 1, 2 and 3, respectively (p = 0.370). Mean IOPcc values were 16.5 ± 3.6 (8.1-27.3), 16.7 ± 2.7 (12.0-22.7) and 16.3 ± 3.3 (10.8-27.4) mmHg (p = 0.889); mean IOPg values were 16.8 ± 5.0 (6.5-39.5), 16.3 ± 2.9 (10.3-23.0) and 15.9 ± 3.2 (10.0-26.0) mmHg (p = 0.539); mean CH values were 10.8 ± 1.9 (8.3-19.0), 11.4 ± 1.6 (6.9-14.0) and 11.2 ± 1.5 (7.5-13.2) (p = 0.257); mean CRF values were 10.5 ± 2.7 (7.4-25.0), 11.1 ± 1.5 (6.8-13.5) and 10.5 ± 1.2 (7.7-12.8) (p = 0.282) in groups 1, 2 and 3, respectively. There was no statistical difference between the groups in terms of IOPcc, IOPg CH and CRF. However, mean CH values were found less in the lack of vitamin D group.

CONCLUSION

The CH values were lower, and the IOPg values were higher in cases of vitamin D deficiency. Corneal biomechanical differences in patients with lack of vitamin D were not statistically significant.

Air pollutant particulate matter 2.5 induces dry eye syndrome in mice

In this study, we explored the effects of particulate matter 2.5 (PM_2.5) eye drops on the ocular surface structure and tear function in mice and established a novel animal model for dry eye research. We found that, following treatment with PM_2.5, the tear volume and, the tear film break-up time showed statistical differences at each time point (P < 0.05). The FL score of the PM_2.5-treated group was higher than that of others (P < 0.05). The average number of corneal epithelial layer cells in groups A and B was significantly lower than that in group C (P < 0.05). Scanning electron microscopy and transmission electron microscopy revealed that the number of corneal epithelial microvilli and corneal desmosomes was drastically reduced in group C. PM_2.5 induced apoptosis in the corneal superficial and basal epithelium and led to abnormal differentiation and proliferation of the ocular surface with higher expression levels of Ki67 and a reduced number of goblet cells in the conjunctival fornix in group C. PM_2.5 significantly increased the levels of TNF-α, NF-κB p65 (phospho S536), and NF-κB in the cornea. Thus, the topical administration of PM_2.5 in mice induces ocular surface changes that are similar to those of dry eye in humans, representing a novel model of dry eye.

Corneal endothelial changes in patients with vitamin D deficiency

Purpose:

The purpose of this study is to evaluate the effect of vitamin D deficiency on corneal endothelial layer using specular microscopy.

Methods:

Fifty-eight eyes of 58 patients whose vitamin D level was below 15 ng/ml and who had no ocular pathology were included in the study (Group 1). Forty eyes of 40 age-and sex-matched subjects were enrolled as control group (Group 2). Corneal endothelial cell density (CD), coefficient of variation (CV), hexagonal cell ratio (HEX), and central corneal thickness (CCT) were measured using specular microscopy (Konan Medical Inc., Nishinomiya, Japan). The obtained data were compared between the groups.

Results:

There was no significant difference between the groups in terms of age and gender (P = 0.344, P = 0.399, respectively). The mean CD value was 2772.79 ± 202.21 cells/mm² in Group 1 and 2954.97 ± 116.89 cells/mm² in Group 2 (P = 0.001). The mean CV value was 30.31 ± 3.65 in Group 1 and 28.20 ± 2.71 in Group 2 (P = 0.003). The mean HEX value was 46.56 ± 6.32 in Group 1 and 51.07 ± 5.28 in Group 2 (P = 0.001). The mean CCT value was 555.87 ± 36.90 μ in group 1 and 549.0 ± 37.39 μ in Group 2 (P = 0.96).

Conclusion:

Vitamin D deficiency may affect the corneal endothelial layer. Patients with vitamin D deficiency should be evaluated for endothelial parameters in particular before an intraocular surgery. Further studies are needed to confirm our results.

Dry eye disease and oxidative stress

Dry eye, an age-related condition, is a multifactorial disease of the tears and ocular surface that results in symptoms of discomfort, visual disturbance and tear film instability. Environmental factors are also often implicated in dry eye including exposure to pollutants, ultraviolet (UV) radiation and ozone as well as the chronic use of preserved eyedrops such as in the treatment of glaucoma. These factors increase oxidative stress and ocular surface inflammation. Here, we reviewed the cellular, animal and clinical studies that point to the role of oxidative stress in dry eye disease. The biomarkers used to indicate oxidative damage in ocular surface tissues include 8-hydroxy-2 deoxyguanosine (8-OHdG), 4-hydroxynonenal (HNE) and malondialdehyde (MDD). Antioxidative defences in the ocular surface occur in the form of tear proteins such as lactoferrin and S100A proteins, and enzymes such as superoxide dismutase (SOD), peroxidase, catalase and mitochondrial oxidative enzymes. An imbalance between the level of reactive oxygen species (ROS) and the action of protective enzymes will lead to oxidative damage, and possibly inflammation. A small number of interventional studies suggest that oxidative stress may be directly targeted in topical therapy of dry eye treatment. For example, in vitro studies suggest that L-carnitine and pterostilbene, a blueberry component may reduce oxidative stress, and in animal studies, alpha-lipoic acid (ALP) and selenoprotein P may be helpful. Examples of treatments used in clinical trials include vitamin B12 eyedrops and iodide iontophoresis. With recent emphasis on ageing medicine and preventive holistic health, as well as the role of environmental science, research on oxidative stress in the ocular surface is likely to have increasing impact in the coming years.

Effect of mistletoe combined with carboxymethyl cellulose on dry eye in postmenopausal women

AIM

To investigate the protective effect of mistletoe combined with carboxymethyl cellulose eye drops on dry eye in postmenopausal women.

METHODS

Sixty postmenopause female patients diagnosed of dry eye were assigned randomly to mistletoe combined with carboxymethyl cellulose eye drops treatment group (n=30) and control group treated with normal saline eye drops (n=30). The subjective symptoms of ocular surface, Ocular Surface Disease Index (OSDI), tear film function tests, tear protein and corneal morphology by confocal scanning microscopy were analyzed before treatment and at 1, 2, 4 and 8wk after treatment respectively. To ensure the safety of the trial, all patients were examined with systolic pressure, diastolic pressure, glutamic-pyruvic transaminase, glutamic oxaloacetic transaminase, urine creatinine, and blood urea nitrogen at 8wk after treatment.

RESULTS

There were no obvious differences between two groups before the treatment (P>0.05). In two months after the treatment, the symptoms of ocular surface, OSDI, tear protein, and tear film function were only slightly changed in normal saline eye drops group. However, all indices were improved after the treatment of mistletoe combined with carboxymethyl cellulose eye drops group (P<0.05). In addition, the average amount of corneal epithelium basal cells and inflammatory cells of mistletoe treated group were 3174±379 and 38±25 cells/mm², significantly decreased as compared to the control group with 4309±612 and 158± 61 cells/mm², respectively. In the control group, although nerves still maintained straight under corneal epithelium, the number of nerves were significantly decreased, as compared with normal female. In the mistletoe treated group, the number of nerves was only slightly reduced, compared with normal female.

CONCLUSION

Mistletoe combined with carboxymethyl cellulose eye drops can alleviate the symptoms and signs of dry eye symptoms.

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.