Effects of a nutraceutical formulation based on the combination of antioxidants and ω-3 essential fatty acids in the expression of inflammation and immune response mediators in tears from patients with dry eye disorders

Tear metabolomics for the diagnosis of primary open-angle glaucoma

Primary Open-Angle Glaucoma (POAG) is the most prevalent glaucoma type, and the leading cause of irreversible visual impairment and blindness worldwide. Identification of early POAG biomarkers is of enormous value, as there is not an effective treatment for the glaucomatous optic nerve degeneration (OND). In this pilot study, a metabolomic analysis, by using proton (1H) nuclear magnetic resonance (NMR) spectroscopy was conducted in tears, in order to determine the changes of specific metabolites in the initial glaucoma eyes and to discover potential diagnostic biomarkers. A classification model, based on the metabolomic fingerprint in tears was generated as a non-invasive tool to support the preclinical and clinical POAG diagnosis. 1H NMR spectra were acquired from 30 tear samples corresponding to the POAG group (n = 11) and the control group (n = 19). Data were analysed by multivariate statistics (partial least squares-discriminant analysis: PLS-DA) to determine a model capable of differentiating between groups. The whole data set was split into calibration (65%)/validation (35%), to test the performance and the ability for glaucoma discrimination. The calculated PLS-DA model showed an area under the curve (AUC) of 1, as well as a sensitivity of 100% and a specificity of 83.3% to distinguish POAG group versus control group tear data. This model included 11 metabolites, potential biomarkers of the disease. When comparing the study groups, a decrease in the tear concentration of phenylalanine, phenylacetate, leucine, n-acetylated compounds, formic acid, and uridine, was found in the POAG group. Moreover, an increase in the tear concentration of taurine, glycine, urea, glucose, and unsaturated fatty acids was observed in the POAG group. These results highlight the potential of tear metabolomics by 1H NMR spectroscopy as a non-invasive approach to support early POAG diagnosis and in order to prevent visual loss.

Is fat the future for saving sight? Bioactive lipids and their impact on glaucoma

Glaucoma is characterized by a continuous loss of retinal ganglion cells. The cause of glaucoma is associated with an increase in intraocular pressure (IOP), but the underlying pathophysiology is diverse and, in most cases, unknown. There is an indisputable unmet need to identify new pathways involved in glaucoma pathogenesis. Increasing evidence suggests that bioactive lipids may be critical in the development and progression of glaucoma. Preclinical and clinical bioactive lipid targets exist and are being developed. In this review, we aim to shed light on the potential of bioactive lipids for the prevention, diagnosis, prognosis, and treatment of glaucoma by asking the question "is fat the future for saving sight".

Associations between intake of dietary micro- and macro-nutrients with Dry eye syndrome: Blue Mountains Eye Study

BACKGROUND AND AIMS

To report on the relationship between dietary intakes of a broad range of macronutrients and micronutrients, including antioxidants and fatty acids, with the presence of dry eye symptoms.

METHODS

Population-based cross-sectional study of 1952 urban Sydney residents aged 60 years or greater. Participants completed a validated semi-quantitative 145-item food frequency questionnaire and a dry eye questionnaire.

RESULTS

A total of 1528 responses were recorded (78.3%) of which 902 (59.0%) were female. 53.8% of participants reported at least one dry eye symptom, more commonly by women (58.2%) compared to men (47.3%). Participants in the highest (8.11 mcg/day) versus lowest quartile of intake of dietary B12 had reduced likelihood of reporting more than 2 dry eye symptoms and 1 or more moderate-severe dry eye symptoms: OR 0.64 (95% CI: 0.41-1.00) and OR 0.63 (95% CI: 0.41-0.97), respectively. Higher dietary intakes of vitamin C, thiamine (vitamin B1), polyunsaturated fats and calcium, were all associated with a reduced likelihood of participants reporting more than 2 dry eye symptoms (p < 0.05 for all).

CONCLUSIONS

Intakes of a broad range of micro- and macro-nutrients were significantly and independently associated with reduced odds of experiencing dry eye symptoms. These data suggest that clinicians may need to consider current diet in patients presenting with dry eye symptoms.

Effect of Omega-3 on HLA-DR Expression by Conjunctival Cells and Tear Cytokine Concentrations in the Dry Eye Assessment and Management Study

OBJECTIVES

To determine effect of omega-3 supplementation on conjunctival cell HLA-DR expression and tear concentrations of interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-17A, interferon-γ, and tumor necrosis factor-α in dry eye disease patients in the Dry Eye Assessment and Management study.

METHODS

Patients were randomized to receive a daily dose of eicosapentaenoic and docosahexaenoic acids (ω3) or refined olive oil (placebo) for 12 months. At baseline, 6 and 12 months, HLA-DR expression in conjunctival total, epithelial, and white blood cells and cytokine concentration in tears were determined. Differences in change from baseline between treatment groups were assessed using generalized estimating equations (HLA-DR) or Wilcoxon rank-sum test (cytokines).

RESULTS

No differences were observed in HLA-DR expression in total, epithelial, or white blood cells between ω3 and placebo groups at 6 months (n=435) or 12 months (n=436). The median concentration percent change differed between ω3 and placebo groups at 6 months for IL-6 (-36.6 vs. 24.5%, P =0.02, n=75) and for IL-8 (3.7% vs. 72.6%, P =0.02, n=68); at 12 months, they did not differ ( P ≥0.18). No other differences between the treatment groups were detected.

CONCLUSIONS

ω3 supplementation did not consistently affect ocular inflammatory status as measured by the frequency of HLA-DR expressing conjunctival cells or tear cytokines.

Oxidative Stress in the Protection and Injury of the Lacrimal Gland and the Ocular Surface: are There Perspectives for Therapeutics?

Oxidative stress (OS) is a major disruption in the physiology of the lacrimal functional unit (LFU). Antioxidant enzymes have dual protective activities: antioxidant and antimicrobial activities. Peroxidases have been indistinctly used as markers of the secretory activity of the LFU and implicated in the pathophysiology, diagnosis and treatment of dry eye disease (DED), even though they comprise a large family of enzymes that includes lactoperoxidase (LPO) and glutathione peroxidase (GPO), among others. Assays to measure and correlate OS with other local LFU phenomena have methodological limitations. Studies implicate molecules and reactions involved in OS as markers of homeostasis, and other studies identify them as part of the physiopathology of diseases. Despite these conflicting concepts and observations, it is clear that OS is influential in the development of DED. Moreover, many antioxidant strategies have been proposed for its treatment, including calorie restriction to nutritional supplementation. This review offers a critical analysis of the biological mechanisms, diagnostic outcomes, drug use, dietary supplements, and life habits that implicate the influence of OS on DED.

Metabolomic Alterations in the Tear Fluids of Patients With Superior Limbic Keratoconjunctivitis

Purpose

Superior limbic keratoconjunctivitis (SLK) is a bilateral, chronic inflammatory disease that recurs for up to several years; however, the fundamental processes involved in its pathogenic mechanisms remain unknown. We aimed to investigate the metabolomic alterations in the tear fluids of patients with superior limbic keratoconjunctivitis (SLK) compared with those of healthy volunteers (Ctrl group).

Methods

We performed a cross-sectional study involving 42 subjects. Tear fluid was taken from one eye of 24 SLK patients (40.13 ± 14.55 years, 83.33% female) and 18 healthy volunteers (Ctrl, 39.89 ± 9.2 years, 72.22% female) using Schirmer strips. After the liquid extraction of tear metabolites, samples were infused into the QE HFX Orbitrap mass spectrometer in both positive and negative ion mode. Metabolites were quantitatively analyzed and matched with entries in the HMDB database. Metabolic differences between the SLK group and the control group were identified based on multivariate statistical analysis. Open database sources, including SMPDB and MetaboAnalyst, were used to identify metabolic pathways.

Results

Among 179 metabolites retained for annotation, 133 metabolites were finally identified, among which 50 were found to be significantly changed in SLK patients. Of these 50 metabolites, 31 metabolites significantly increased and 19 metabolites decreased in SLK patients. The altered metabolites are mainly involved in α linolenic acid and linoleic acid metabolism, ketone body metabolism, butyrate metabolism, mitochondrial electron transport chain, carnitine synthesis, and so on. The most significantly changed pathway was linoleic acid metabolism. To explore the utility of tear biomarkers, a model combining 9 metabolites (phenol, ethyl glucuronide, eicosapentaenoic acid, 12-keto-leukotriene B4, linoleic acid, hypoxanthine, triethanolamine, 1-nitrohexane, and terephthalic acid) was selected as a candidate biomarker.

Conclusion

The results reveal that SLK has a specific metabolomic profile, of which some key elements can serve as potential biomarkers of SLK for diagnostic and prognostic purposes. The findings of this study are novel and provide a basis for further investigations of the mechanism of SLK.

Searching for the Antioxidant, Anti-Inflammatory, and Neuroprotective Potential of Natural Food and Nutritional Supplements for Ocular Health in the Mediterranean Population

Adherence to a healthy diet offers a valuable intervention to compete against the increasing cases of ocular diseases worldwide, such as dry eye disorders, myopia progression, cataracts, glaucoma, diabetic retinopathy, or age macular degeneration. Certain amounts of micronutrients must be daily provided for proper functioning of the visual system, such as vitamins, carotenoids, trace metals and omega-3 fatty acids. Among natural foods, the following have to be considered for boosting eye/vision health: fish, meat, eggs, nuts, legumes, citrus fruits, nuts, leafy green vegetables, orange-colored fruits/vegetables, olives-olive oil, and dairy products. Nutritional supplements have received much attention as potential tools for managing chronic-degenerative ocular diseases. A systematic search of PubMed, Web of Science, hand-searched publications and historical archives were performed by the professionals involved in this study, to include peer-reviewed articles in which natural food, nutrient content, and its potential relationship with ocular health. Five ophthalmologists and two researchers collected the characteristics, quality and suitability of the above studies. Finally, 177 publications from 1983 to 2021 were enclosed, mainly related to natural food, Mediterranean diet (MedDiet) and nutraceutic supplementation. For the first time, original studies with broccoli and tigernut (chufa de Valencia) regarding the ocular surface dysfunction, macular degeneration, diabetic retinopathy and glaucoma were enclosed. These can add value to the diet, counteract nutritional defects, and help in the early stages, as well as in the course of ophthalmic pathologies. The main purpose of this review, enclosed in the Special Issue "Health Benefits and Nutritional Quality of Fruits, Nuts and Vegetables," is to identify directions for further research on the role of diet and nutrition in the eyes and vision, and the potential antioxidant, anti-inflammatory and neuroprotective effects of natural food (broccoli, saffron, tigernuts and walnuts), the Mediterranean Diet, and nutraceutic supplements that may supply a promising and highly affordable scenario for patients at risk of vision loss. This review work was designed and carried out by a multidisciplinary group involved in ophthalmology and ophthalmic research and especially in nutritional ophthalmology.

Signature of Circulating Biomarkers in Recurrent Non-Infectious Anterior Uveitis. Immunomodulatory Effects of DHA-Triglyceride. A Pilot Study

The purpose of this study was to identify circulating biomarkers of recurrent non-infectious anterior uveitis (NIAU), and to address the anti-inflammatory effects of triglyceride containing docosahexaenoic acid (DHA-TG). A prospective multicenter study was conducted in 72 participants distributed into: patients diagnosed with recurrent NIAU in the quiescence stage (uveitis group (UG); n = 36) and healthy controls (control group (CG); n = 36). Each group was randomly assigned to the oral supplementation of one pill/day (+) containing DHA-TG (n = 18) or no-pill condition (−) (n = 17) for three consecutive months. Data from demographics, risk factors, comorbidities, eye complications and therapy were recorded. Blood was collected and processed to determine pro-inflammatory biomarkers by bead-base multiplex assay. Statistical processing with multivariate statistical analysis was performed. The mean age was 50, 12 (10, 31) years. The distribution by gender was 45% males and 55% females. The mean number of uveitis episodes was 5 (2). Higher plasma expression of interleukin (IL)-6 was detected in the UG versus the CG (p = 5 × 10⁻⁵). Likewise, significantly higher plasma levels were seen for IL-1β, IL-2, INFγ (p = 10⁻⁴), and TNFα (p = 2 × 10⁻⁴) in the UG versus the CG. Significantly lower values of the above molecules were found in the +DHA-TG than in the -DHA-TG subgroups, after 3 months of follow-up, TNFα (p = 10⁻⁷) and IL-6 (p = 3 × 10⁻⁶) being those that most significantly changed. Signatures of circulating inflammatory mediators were obtained in the quiescent stage of recurrent NIAU patients. This 3-month follow-up strongly reinforces that a regular oral administration of DHA-TG reduces the inflammatory load and may potentially supply a prophylaxis-adjunctive mediator for patients at risk of uveitis vision loss.

Computational Analysis of Clinical and Molecular Markers and New Theranostic Possibilities in Primary Open-Angle Glaucoma

Primary open-angle glaucoma (POAG) is a paramount cause of irreversible visual disability worldwide. We focus on identifying clinical and molecular facts that may help elucidating the pathogenic mechanisms of the disease. By using ophthalmological approaches (biomicroscopy, ocular fundus, optical coherence tomography, and perimetry) and experimental tests (enzyme-linked immunosorbent assay (ELISA), high performance liquid chromatography (HPLC), and Western blot/immunoblotting) directed to evaluate the oxidative stress, inflammation, apoptosis, and neurodegeneration processes, we gather information to build a network of data to perform a computational bioinformatics analysis. Our results showed strong interaction of the above players and its downstream effectors in POAG pathogenesis. In conclusion, specific risk factors were identified, and molecules involved in multiple pathways were found in relation to anterior and posterior eye segment glaucoma changes, pointing to new theranostic challenges for better managing POAG progression.

Comparative lipidomic analysis of inflammatory mediators in the aqueous humor and tear fluid of humans and rabbits

INTRODUCTION

Ocular inflammation is a key pathogenic factor in most blindness-causing visual disorders. It can manifest in the aqueous humor (AH) and tear fluid (TF) as alterations in polyunsaturated fatty acids (PUFAs) and their metabolites, oxylipins, lipid mediators, which are biosynthesized via enzymatic pathways involving lipoxygenase, cyclooxygenase or cytochrome P450 monooxygenase and specifically regulate inflammation and resolution pathways.

OBJECTIVES

This study aimed to establish the baseline patterns of PUFAs and oxylipins in AH and TF by their comprehensive lipidomic identification and profiling in humans in the absence of ocular inflammation and comparatively analyze these compounds in the eye liquids of rabbits, the species often employed in investigative ophthalmology.

METHODS

Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used for qualitative and quantitative characterization of lipid compounds in the analyzed samples.

RESULTS

A total of 28 lipid compounds were identified, including phospholipid derivatives and PUFAs, as well as 22 oxylipins. Whereas the PUFAs included arachidonic, docosahexaenoic and eicosapentaenoic acids, the oxylipins were derived mainly from arachidonic, linoleic and α-linolenic acids. Remarkably, although the concentration of oxylipins in AH was lower compared to TF, these liquids showed pronounced similarity in their lipid profiles, which additionally exhibited noticeable interspecies concordance.

CONCLUSION

The revealed correlations confirm the feasibility of rabbit models for investigating pathogenesis and trialing therapies of human eye disorders. The identified metabolite patterns suggest enzymatic mechanisms of oxylipin generation in AH and TF and might be used as a reference in ocular inflammation studies.

Omega-3 and omega-6 polyunsaturated fatty acids for dry eye disease

BACKGROUND

Polyunsaturated fatty acid (PUFA) supplements, involving omega-3 and/or omega-6 components, have been proposed as a therapy for dry eye. Omega-3 PUFAs exist in both short- (alpha-linolenic acid [ALA]) and long-chain (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) forms, which largely derive from certain plant- and marine-based foods respectively. Omega-6 PUFAs are present in some vegetable oils, meats, and other animal products.

OBJECTIVES

To assess the effects of omega-3 and omega-6 polyunsaturated fatty acid (PUFA) supplements on dry eye signs and symptoms.

SEARCH METHODS

CENTRAL, Medline, Embase, two other databases and three trial registries were searched in February 2018, together with reference checking. A top-up search was conducted in October 2019, but the results have not yet been incorporated.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) involving dry eye participants, in which omega-3 and/or omega-6 supplements were compared with a placebo/control supplement, artificial tears, or no treatment. We included head-to-head trials comparing different forms or doses of PUFAs.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods and assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 34 RCTs, involving 4314 adult participants from 13 countries with dry eye of variable severity and etiology. Follow-up ranged from one to 12 months. Nine (26.5%) studies had published protocols and/or were registered. Over half of studies had high risk of bias in one or more domains. Long-chain omega-3 (EPA and DHA) versus placebo or no treatment (10 RCTs) We found low certainty evidence that there may be little to no reduction in dry eye symptoms with long-chain omega-3 versus placebo (four studies, 677 participants; mean difference [MD] -2.47, 95% confidence interval [CI] -5.14 to 0.19 units). We found moderate certainty evidence for a probable benefit of long-chain omega-3 supplements in increasing aqueous tear production relative to placebo (six studies, 1704 participants; MD 0.68, 95% CI 0.26 to 1.09 mm/5 min using the Schirmer test), although we did not judge this difference to be clinically meaningful. We found low certainty evidence for a possible reduction in tear osmolarity (one study, 54 participants; MD -17.71, 95% CI -28.07 to -7.35 mOsmol/L). Heterogeneity was too substantial to pool data on tear break-up time (TBUT) and adverse effects. Combined omega-3 and omega-6 versus placebo (four RCTs) For symptoms (low certainty) and ocular surface staining (moderate certainty), data from the four included trials could not be meta-analyzed, and thus effects on these outcomes were unclear. For the Schirmer test, we found moderate certainty evidence that there was no intergroup difference (four studies, 455 participants; MD: 0.66, 95% CI -0.45 to 1.77 mm/5 min). There was moderate certainty for a probable improvement in TBUT with the PUFA intervention relative to placebo (four studies, 455 participants; MD 0.55, 95% CI 0.04 to 1.07 seconds). Effects on tear osmolarity and adverse events were unclear, with data only available from a single small study for each outcome. Omega-3 plus conventional therapy versus conventional therapy alone (two RCTs) For omega-3 plus conventional therapy versus conventional therapy alone, we found low certainty evidence suggesting an intergroup difference in symptoms favoring the omega-3 group (two studies, 70 participants; MD -7.16, 95% CI -13.97 to -0.34 OSDI units). Data could not be combined for all other outcomes. Long-chain omega-3 (EPA and DHA) versus omega-6 (five RCTs) For long-chain omega-3 versus omega-6 supplementation, we found moderate certainty evidence for a probable improvement in dry eye symptoms (two studies, 130 participants; MD -11.88, 95% CI -18.85 to -4.92 OSDI units). Meta-analysis was not possible for outcomes relating to ocular surface staining, Schirmer test or TBUT. We found low certainty evidence for a potential improvement in tear osmolarity (one study, 105 participants; MD -11.10, 95% CI -12.15 to -10.05 mOsmol/L). There was low level certainty regarding any potential effect on gastrointestinal side effects (two studies, 91 participants; RR 2.34, 95% CI 0.35 to 15.54).

AUTHORS' CONCLUSIONS

Overall, the findings in this review suggest a possible role for long-chain omega-3 supplementation in managing dry eye disease, although the evidence is uncertain and inconsistent. A core outcome set would work toward improving the consistency of reporting and the capacity to synthesize evidence.

The Dry Eye Assessment and Management (DREAM) extension study - A randomized clinical trial of withdrawal of supplementation with omega-3 fatty acid in patients with dry eye disease

PURPOSE

To determine effects of continued or discontinued use of omega-3 (ω3) fatty acid supplements through a randomized withdrawal trial among patients assigned to ω3 supplements in the first year of the DREAM study.

METHODS

Patients who were initially assigned to ω3 (3000 mg) for 12 months in the primary trial were randomized 1:1 to ω3 active supplements or placebos (refined olive oil) for 12 more months. The primary outcome was change in the Ocular Surface Disease Index (OSDI) score. Secondary outcomes included change in conjunctival staining, corneal staining, tear break-up time, Schirmer test, and adverse events.

RESULTS

Among 22 patients assigned to ω3 and 21 to placebo supplements, the mean change in OSDI score between month 12 and 24 was similar between treatment groups (mean difference in change -0.6 points, 95% confidence interval [CI], (-10.7, 9.5), p = 0.91). There were no significant differences between groups in mean change in conjunctival staining (difference in mean change -0.5 points; 95% CI (-1.2, 0.3)), corneal staining (-0.3 points; 95% CI (-1.2, 0.3)), tear break-up time (-0.8 s; 95% CI (-2.6, 0.9)) and Schirmer test (0.6 mm, 95% CI (-2.0, 3.2)). Rates of adverse events were similar in both groups.

CONCLUSION

Among patients who received ω3 supplements for 12 months in the primary trial, those discontinuing use of ω3 for an additional 12 months did not have significantly worse outcomes compared to those who continued use of ω3. ClinicalTrials.gov number NCT02128763.

Effects of Polyunsaturated Fatty Acids on Nonspecific Typical Dry Eye Disease: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

To investigate the effects of polyunsaturated fatty acids (PUFAs) in patients with dry eye disease (DED), a multifactorial inflammatory disorder, we searched Cochrane Library, EMBASE, PubMed, and Web of Science for randomized clinical trials (RCTs) investigating the effect of PUFAs in patients with DED before March 2019. Two reviewers independently abstracted data of tear breakup time (TBUT), Schirmer’s test, osmolarity, and ocular surface disease index (OSDI). We conducted pairwise meta-analysis using means and standard deviations (SDs) in a random-effects model for continuous outcomes. Thirteen eligible RCTs with 1782 patients with nonspecific typical DED were included. Patients who received PUFA treatment without other eye medications exhibited greater improvements in TBUT (MD = 1.80; p = 0.001), Schirmer test scores (MD = 0.50; p < 0.001), osmolarity (MD = −15.95; p < 0.001), and OSDI scores (MD = −10.19; p < 0.001) than those who received placebo treatment. However, the effects of PUFAs on TBUT (p < 0.001) and OSDI scores (p = 0.03) weakened with treatment duration. PUFAs are effective in treating nonspecific typical DED, particularly as a short-term treatment, with relatively few adverse events. Therefore, in real-world clinical practice, PUFA supplements are worth being suggested to patients with nonspecific typical DED who are not concurrently using other topical or systematic eye medications.

Potentiality of microemulsion systems in treatment of ophthalmic disorders: Keratoconus and dry eye syndrome - In vivo study

Microemulsions are widely studied as potential ocular drug delivery vehicles. In the present study we show the versatility of possible use microemulsions as ocular delivery vehicle. The ME is loaded with a hydrophilic drug, riboflavin phosphate (RFP) and a lipophilic, docosahexaenoic acid in triglyceride form (TG-DHA), each separately. These drugs treat keratoconus and dry eye syndrome, respectively. The advantage of using ME loaded with RFP is in overcoming eye epithelium debridement during collagen cross-linking therapy for treatment of keratoconus. ME loaded with lipophilic TG-DHA provides convenient dosage in liquid aqueous form of administration of highly lipophilic TG-DHA, which is known as a protective molecule in dry eye syndrome. The capability of RFP-loaded MEs was demonstrated in terms of improvement of biomechanical strength of the rabbit cornea, as a result of successful penetration of RFP through the intact epithelium. TG-DHA-loaded microemulsion applied topically onto an eye with induced dry eye syndrome showed the significant relief of the dry eye condition.

Cytokine expression in tears of patients with glaucoma or dry eye disease: A prospective, observational cohort study

BACKGROUND

The aim of this study was to assess the expression of cytokines/chemokines in tears from patients with non-advanced primary open-angle glaucoma and patients with non-severe dry eye disease versus healthy controls.

METHODS

This prospective, observational cohort study enrolled patients with confirmed or suspected non-advanced primary open-angle glaucoma who received any prostaglandin analogue monotherapy for longer than 6 months, patients with non-severe dry eye disease, and healthy controls. Expression of interleukin-1β, interleukin-2, interleukin-4, interleukin-5, interleukin-6, interleukin-8, interleukin-10, and interleukin-12; tumor necrosis factor α; vascular endothelial growth factor; granulocyte-macrophage colony-stimulating factor; and interferon γ was assessed.

RESULTS

107 participants were enrolled (primary open-angle glaucoma, n = 41; dry eye disease, n = 30; and healthy controls, n = 36). Compared with healthy controls, interleukin-6 was significantly higher (p = 0.0001) in patients with primary open-angle glaucoma and interleukin-1β (p = 0.0144), interleukin-6 (p < 0.0001), and interleukin-10 (p = 0.0392) were higher in patients with dry eye disease. Compared with patients with dry eye disease, patients with primary open-angle glaucoma had significantly lower levels of interleukin-4 (21.79 vs 20.18 pg/mL; p = 0.0012) and significantly higher levels of vascular endothelial growth factor (367.75 vs 609.28 pg/mL; p = 0.0058), tumor necrosis factor α (14.27 vs 17.93 pg/mL; p = 0.0048), and interleukin-6 (17.95 vs 27.48 pg/mL; p = 0.0145). In patients with primary open-angle glaucoma, interleukin-1β expression (p = 0.0011) was lower than in those who received intraocular pressure-lowering eye drops without preservatives compared with those who received eye drops with preservatives.

CONCLUSION

Different cytokine/chemokine expression profiles in tears of patients with primary open-angle glaucoma and dry eye disease strongly suggest the involvement of a variety of signaling pathways in the pathogenesis of these ophthalmic processes.

RGN-259 (thymosin β4) improves clinically important dry eye efficacies in comparison with prescription drugs in a dry eye model

This study evaluated the clinical activity of RGN-259 (thymosin β4) in comparison with cyclosporine A (CsA), diquafosol (DQS), and lifitegrast (LFA) in a murine model of dry eye. The model was NOD.B10-H2^b mice in a 30–40% humidified environment together with daily scopolamine hydrobromide injections for 10 days. After desiccation stress, all drugs were evaluated after 10 treatment days. RGN-259 increased tear production similar to that in the DQS- and LFA-treated mice while CsA was inactive. RGN-259 improved corneal smoothness and decreased fluorescein staining similar to that of LFA group while CsA and DQS were inactive. Corneal epithelial detachment was reduced by RGN-259, and DQS and LFA showed similar activity but the CsA was inactive. RGN-259 increased conjunctival goblet cells and mucin production comparable to that seen with CsA, while DQS and LFA were inactive. RGN-259 reduced the over-expression of inflammatory factors comparable to that with CsA and LFA, while DQS was inactive. RGN-259 increased mucin production comparable to that observed with CsA, while DQS and LFA were inactive. In conclusion, RGN-259 promoted recovery of mucins and goblet cells, improved corneal integrity, and reduced inflammation in a dry eye mouse model and was equal to or more effective than prescription treatments.

Supplementation with a highly concentrated docosahexaenoic acid plus xanthophyll carotenoid multivitamin in nonproliferative diabetic retinopathy: prospective controlled study of macular function by fundus microperimetry

Objective

There is little evidence of real-life outcomes of dietary supplementation with high-dose docosahexaenoic acid (DHA) and carotenoids in patients with diabetic retinopathy (DR). We assessed the effect of supplementation with DHA triglyceride (1,050 mg/d) + xanthophyll carotenoid multivitamin on macular function in nonproliferative DR.

Methods

Asymptomatic patients with nonproliferative DR were included in a prospective controlled study and assigned (1:1) to the DHA supplementation group or the control group. Macular sensitivity and macular integrity area were the main outcome measures. Functional vision measures (macular function [MAIA™ CenterVue], best-corrected visual acuity), structural retinal measures (central subfield macular thickness), and biochemical parameters (plasma total antioxidant capacity, DHA content of the erythrocyte membrane, and plasma IL-6) were evaluated at baseline and after 45 and 90 days of DHA supplementation.

Results

The study included 24 patients (48 eyes) (12 patients, 24 eyes in each group). Baseline clinical characteristics of patients in both groups were similar. Macular sensitivity increased from a mean (SD) of 25.9 (2.4) dB at baseline to 27.3 (2.3) dB at 90 days (P=0.030) in the DHA group only (between-group differences P<0.19). The macular integrity index decreased from 71.2 (33.2) at baseline to 63.5 (36.4) at 45 days and to 51.6 (35.9) at 90 days (P=0.002) in the DHA group only (between-group differences P<0.05). Best-corrected visual acuity and central subfield macular thickness did not vary significantly in any of the comparisons and in none of the groups. DHA content of erythrocyte membrane and total antioxidant capacity levels increased significantly only in the DHA group. Plasma IL-6 levels decreased significantly only in the DHA group.

Conclusion

In an early stage of DR, supplementation with high-dose DHA plus xanthophyll carotenoid multivitamin during 90 days was associated with a progressive and significant improvement of macular function measured by microperimetry. Biochemical changes supported the effect of DHA.

Relation Between Dietary Essential Fatty Acid Intake and Dry Eye Disease and Meibomian Gland Dysfunction in Postmenopausal Women

PURPOSE

To evaluate the relationship between omega-3 (n-3) and omega-6 (n-6) fatty acids with dry eye disease (DED) and meibomian gland dysfunction (MGD).

DESIGN

Cross-sectional study.

METHODS

Postmenopausal women (n = 439) underwent a clinical evaluation and completed the Vio Food Frequency Questionnaire to estimate their dietary intake of n-3s and n-6s. Subjects were categorized into 2 binary classifications based on whether or not they had (1) DED and (2) MGD. Mean intake of dietary fatty acids was compared with 2-sample t tests. Univariate logistic regression models were used to estimate the odds ratios for each condition associated with each quintile of n-3s, n-6s, and n-6:n-3 ratios.

RESULTS

For DED vs non-DED, there were no significant differences in n-3 intake (1.95 ± 1.47 g vs 1.92 ± 1.24 g, P = .86), n-6 intake (15.58 ± 11.56 g vs 15.44 ± 10.61 g, P = .91), and n-6:n-3 (8.30 ± 2.57 vs 8.30 ± 2.57, P = .99). For MGD vs non-MGD, there were no significant differences in n-3 intake (1.87 ± 1.35 vs 1.96 ± 1.39, P = .61), n-6 intake (15.26 ± 11.85 vs 15.62 ± 10.93, P = .80), and n-6:n-3 (8.35 ± 2.94 vs 8.28 ± 2.42, P = .84). The odds ratios (OR) for DED did not differ significantly from 1.0 for n-3, n-6, or n-6:n-3. High n-3 consumption (OR = 0.22 [0.06–0.78]) and moderate n-6 consumption (OR = 0.37 [0.15–0.91]) were associated with a decreased frequency of MGD.

CONCLUSIONS

Dietary consumption of n-3s and n-6s showed no association with DED, but high n-3 consumption and moderate n-6 consumption were protective against MGD in this large sample of postmenopausal women.

COMBINED INTRAVITREAL RANIBIZUMAB AND ORAL SUPPLEMENTATION WITH DOCOSAHEXAENOIC ACID AND ANTIOXIDANTS FOR DIABETIC MACULAR EDEMA: Two-Year Randomized Single-Blind Controlled Trial Results

PURPOSE

To assess the 2-year effectiveness of intravitreal ranibizumab combined with a dietary supplement rich in docosahexaenoic acid (DHA) plus antioxidants in 62 patients with diabetic macular edema.

METHODS

In a randomized single-blind controlled study, 33 subjects (42 eyes) received intravitreal ranibizumab alone and 29 (34 eyes) combined with DHA (1,050 mg/day). Monthly ranibizumab (0.5 mg) was given for the first 4 months followed by on as-needed treatment.

RESULTS

At 24 months, the difference between groups in the decrease of central subfield macular thickness was significant in favor of the DHA supplementation group (95% confidence interval of the difference 7.20-97.656; P = 0.024), although improvement in best-corrected visual acuity measured in the Early Treatment Diabetic Retinopathy Study letters did not reach statistical significance (95% confidence interval 5.4-11.2, P < 0.66). At 24 months, gains of >5 and >10 letters were significantly higher in the DHA supplementation group as compared with controls when the worse and better seeing eyes were considered but other differences at 12 months and 24 months were not found.

CONCLUSION

Intravitreal ranibizumab combined with DHA supplementation reduced central subfield macular thickness after 2 years of follow-up as compared with ranibizumab alone in patients with diabetic macular edema. This anatomical improvement was accompanied by a trend for an amelioration of vision.

Determination of inmune response and inflammation mediators in tears: Changes in dry eye and glaucoma as compared to healthy controls

OBJECTIVE

To determine the expression profile of immune response and inflammation (IRI) mediator molecules in tears from patients with dry eye (DE), and those suspected of having or have primary open-angle glaucoma (POAG) under treatment and compare them with healthy controls.

METHODS

A prospective observational cohort study including 107 participants sub-divided into: healthy controls (CG; n=30), patients with DE (DEG; n=41) and patients suspected of having or have POAG and on hypotensive treatment (POAG-G; n=36). Tear samples were collected by capillary to be processed using a multi-immunoassay system based on flow cytometry (Luminex R-200 ®), in order to determine the interleukins (IL): 1β, 2, 4, 5, 6, and 10, and the growth factors: Tumour necrosis alpha (TNF-α), vascular endothelial (VEGF), and granulocyte-macrophage colony stimulating- (GM-CSF). Data were processed using the SPSS 20.0 program.

RESULTS

Molecules that significantly increased in tears from DEG vs. POAG-G patients were: IL-1 (P=.01), IL-6 (P=.004), IL-10 (P=.04), whereas VEGF significantly decreased in the DEG. The POAG-G showed significantly higher IL-6 values (P<.0001) as compared to the CG. When comparing both the DEG and POAG-G, significant differences were observed in tear expression of IL-4 (P=.004), IL-6 (P=.002), TNF-α (P=.03), GM-CSF (P=.03), and VEGF (P=.002).

CONCLUSIONS

The increased expression of IRI mediators in tears from patients with DE or POAG strongly demonstrated the importance of immune response in both pathologies. However, the different molecules involved also suggest distinct signalling pathways for these processes that still require further research.

Association Between Serum 25-Hydroxyvitamin D Levels and Dry Eye in Korean Adults: A Study Based on Korean National Health and Nutrition Examination Survey, 2010-2011

BACKGROUND

Dry eye is a common disease. Many patients continue to experience residual symptoms despite optimal treatment. Thus, new treatment options are required. The purpose of this study was to evaluate the association between serum 25-hydroxyvitamin D [25(OH)D] levels and dry eye.

METHODS

This study was performed using data from the fifth Korean National Health and Nutrition Examination Survey, which is a cross-sectional study of the Korean population that was conducted from 2010 to 2011. We included adults aged >19 years who underwent ophthalmologic interviews and examinations. We excluded subjects who had comorbid conditions (rheumatoid arthritis, thyroid disease, chronic kidney disease, or depression) that are associated with dry eye. The subjects were divided into normal and dry eye groups. The dry eye group consisted of those who had clinically diagnosed dry eye syndrome or symptoms. Multiple logistic regression analysis was conducted to determine the association between serum 25(OH)D levels and dry eye.

RESULTS

In the univariate model, the 25(OH)D levels were lower in the dry eye group than in the normal group (P=0.01). A significant association was found between severe vitamin D deficiency (<10 ng/mL) and dry eye (P=0.04). However, after multivariate adjustment, the statistical significance of the association disappeared (P-values= 0.49, vitamin D insufficiency; P=0.33, vitamin D deficiency; P=0.18, severe vitamin D deficiency).

CONCLUSION

Severe vitamin D deficiency was associated with dry eye in an unadjusted model, but the association was not statistically significant after adjustment.

Effects of silk fibroin in murine dry eye

The study aimed to investigate the effects of silk fibroin in a mouse model of dry eye. The experimental dry eye mouse model was developed using more than twelve-weeks-old NOD.B10.H2^b mice exposing them to 30–40% ambient humidity and injecting them with scopolamine hydrobromide for 10 days. Tear production and corneal irregularity score were measured by the instillation of phosphate buffered saline or silk fibroin. Corneal detachment and conjunctival goblet cell density were observed by hematoxylin and eosin or periodic acid Schiff staining in the cornea or conjunctiva. The expression of inflammatory markers was detected by immunohistochemistry in the lacrimal gland. The silk group tear production was increased, and corneal smoothness was improved. The corneal epithelial cells and conjunctival goblet cells were recovered in the silk groups. The expression of inflammatory factors was inhibited in the lacrimal gland of the silk group. These results show that silk fibroin improved the cornea, conjunctiva, and lacrimal gland in the mouse model of dry eye. These findings suggest that silk fibroin has anti-inflammatory effects in the experimental models of dry eye.

Ocular Toxicity of Tyrosine Kinase Inhibitors

PURPOSE/OBJECTIVES

To review common tyrosine kinase inhibitors, as well as their ocular side effects and management.
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DATA SOURCES

A comprehensive literature search was conducted using CINAHL®, PubMed, and Cochrane databases for articles published since 2004 with the following search terms.

DATA SYNTHESIS

Tyrosine kinase inhibitors can cause significant eye toxicity.
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CONCLUSIONS

Given the prevalence of new tyrosine kinase inhibitor therapies and the complexity of possible pathogenesis of ocular pathology, oncology nurses can appreciate the occurrence of ocular toxicities and the role of nursing in the management of these problems.
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IMPLICATIONS FOR NURSING

Knowledge of the risk factors and etiology of ocular toxicity of targeted cancer therapies can guide nursing assessment, enhance patient education, and improve care management. Including a review of eye symptoms and vision issues in nursing assessment can enhance early detection and treatment of ocular toxicity.

Effects of adjuvant omega-3 fatty acid supplementation on dry eye syndrome following cataract surgery: A randomized clinical trial

PURPOSE

To investigate the effect of omega-3 polyunsaturated fatty acid supplement on qualitative and quantitative subjective (ocular surface disease index [OSDI]) and objective (Schirmer's test, tear break up time [TBUT], and tear osmolarity) dry eye indices after cataract surgery.

METHODS

In this randomized clinical study, 61 eyes of 48 patients complaining of new onset dry eye symptoms after phacoemulsification were enrolled. Subjects were randomly allocated into two groups using urn randomization. Controls received conventional treatment. The treatment group received omega-3 dietary supplement in addition to conventional therapy.

RESULTS

There was no significant difference between the control and treatment groups in pre-treatment indices of Schirmer (3.50 ± 3.13 and 2.96 ± 3.39, respectively, P = 0.582), TBUT (6.67 ± 1.36 and 4.87 ± 2.22, respectively, P = 0.687), osmolarity (316.66 ± 8.50 and 315.4 ± 17.06, respectively, P = 0.906), and OSDI (32.99 ± 19.03 and 35.32 ± 18.99, respectively, P = 0.635). Mean pre-treatment OSDI in the control group was 32.99 ± 19.03, which improved significantly after treatment to 25.43 ± 14.49 (P = 0.003). The mean pre-treatment OSDI in the treatment group was 35.32 ± 18.99 (range: 7.5-77.77), which improved significantly after treatment to 16.31 ± 13.72 (range: 2.77-47.22) (P < 0.001). OSDI improvement was significantly higher in the treatment group than the control group (P = 0.026). TBUT improved in both the control and treatment groups after treatment (P < 0.001). However, TBUT was affected significantly more in the treatment group compared with the control group (P = 0.038). Mean tear film osmolarity in the control group was 316.67 ± 8.50 (range: 308-325), which improved insignificantly after treatment to 311.33 ± 6.35 (range: 304-315) (P = 0.157). Mean pre-treatment tear film osmolarity in the treatment group was 315.40 ± 17.06 (range: 279-340), which improved significantly after treatment to 296.90 ± 14.39 (range: 260-310) (P < 0.001). Also, post-treatment Schirmer results between the two groups were not statistically significant (P = 0.155).

CONCLUSION

Omega-3 dietary supplements have an additive effect on tear film indices of patients with dry eye syndrome after phacoemulsification.

Systemic treatment for blepharokeratoconjunctivitis in children

BACKGROUND

Blepharokeratoconjunctivitis (BKC) is a type of inflammation of the surface of the eye and eyelids which can affect children and adults. BKC involves changes of the eyelids, dysfunction of the meibomian glands, and inflammation of the conjunctiva and cornea. Chronic inflammation of the cornea can lead to scarring, vascularisation and opacity. BKC in children can cause significant symptoms which include irritation, watering, photophobia and loss of vision. Loss of vision in children with BKC may be due to corneal opacity, refractive error or amblyopia.BKC treatment is directed towards the obstruction of meibomian gland openings, the bacterial flora of lid margin and conjunctiva, and ocular surface inflammation. Dietary modifications that involve increased intake in essential fatty acids (EFAs) may also be beneficial. Both topical and systemic treatments are used; this Cochrane review focuses on systemic treatments.

OBJECTIVES

To assess and compare data on the efficacy and safety of systemic treatments (including antibiotics, nutritional supplements and immunosuppressants), alone or in combination, for BKC in children aged between zero to 16 years.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 3), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to April 2016), EMBASE (January 1980 to April 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 21 April 2016.

SELECTION CRITERIA

We searched for randomised controlled trials that involved systemic treatments in children aged between zero to 16 years with a clinical diagnosis of BKC. We planned to include studies that evaluated a single systemic medication versus placebo, and studies that compared two or multiple active treatments. We planned to include studies in which participants receive additional treatments, such as topical antibiotics, anti-inflammatories and lubricants, warm lid compresses and lid margin cleaning.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the literature search results (titles and abstracts) to identify studies that possibly met the inclusion criteria of the review. We divided studies into 'definitely include', 'definitely exclude' and 'possibly include' categories. We made a final judgement as to the inclusion or exclusion of studies in the 'possibly include' category after we obtained the full text of each article.

MAIN RESULTS

No report or trial met the inclusion criteria of this Cochrane review; no randomised controlled trials have been carried out on this topic. There is a lack of standardised outcome measures.

AUTHORS' CONCLUSIONS

There is currently no evidence from clinical trials regarding the safety and efficacy of systemic treatments for BKC. Trials are required to test efficacy and safety of current and future treatments. Outcome measures need to be developed which can capture both objective clinical and patient-reported aspects of the condition and treatments.

Oral supplementation with a nutraceutical formulation containing omega-3 fatty acids, vitamins, minerals, and antioxidants in a large series of patients with dry eye symptoms: results of a prospective study

Purpose

To assess the benefits and tolerability of a dietary supplement based on omega-3 fatty acids to relieve dry eye symptoms.

Methods

A total of 1,419 patients (74.3% women, mean age 58.9 years) with dry eye syndrome using artificial tears participated in a 12-week prospective study. Patients were instructed to take 3 capsules/day of the nutraceutical formulation (Brudysec^® 1.5 g). Study variables were dry eye symptoms (scratchy and stinging sensation, eye redness, grittiness, painful and tired eyes, grating sensation, and blurry vision), conjunctival hyperemia, tear breakup time (TBUT), Schrimer I test, and Oxford grading scheme.

Results

At 12 weeks, each dry eye symptom improved significantly (P<0.001), and the use of artificial tears decreased significantly from 3.77 (standard deviation [SD] =2.08) at baseline to 3.45 (SD =1.72) (P<0.01). In addition, the Schirmer test scores and the TBUT increased significantly, and there was an increase in patients grading 0–I in the Oxford scale and a decrease of those grading IV–V. Significant differences in improvements of dry eye symptoms were also found in compliant versus noncompliant patients as well as in those with moderate/severe versus none/mild conjunctival hyperemia.

Conclusion

Oral ω-3 fatty acids supplementation was an effective treatment for dry eye symptoms.

Omega-3 fatty acid supplementation improves dry eye symptoms in patients with glaucoma: results of a prospective multicenter study

PURPOSE

The purpose of this study is to assess the effectiveness and tolerability of a dietary supplement with a combination of omega-3 fatty acids and antioxidants on dry eye symptoms caused by chronic instillation of antihypertensive eye drops in patients with glaucoma.

PATIENTS AND METHODS

A total of 1,255 patients with glaucoma and dry eye symptoms related to antiglaucoma topical medication participated in an open-label, uncontrolled, prospective, and multicenter study and were instructed to take three capsules a day of the nutraceutical formulation (Brudypio(®) 1.5 g) for 12 weeks. Dry eye symptoms (graded as 0-3 [none to severe, respectively]), conjunctival hyperemia, tear breakup time, Schirmer I test, Oxford grading scheme, and intraocular pressure were assessed.

RESULTS

After 12 weeks of administration of the dietary supplement, all dry eye symptoms improved significantly (P<0.001) (mean 1.3 vs 0.6 for scratching, 1.4 vs 0.7 for stinging sensation, 1.6 vs 0.7 for grittiness, 1.0 vs 0.4 for tired eyes, 1.1 vs 0.5 for grating sensation, and 0.8 vs 0.3 for blurry vision). The Schirmer test scores and the tear breakup time also increased significantly. There was an increase in the percentage of patients grading 0-I in the Oxford scale and a decrease in those grading IV-V. Compliance was recorded in 62.5% of patients. In compliant patients, the mean differences at 12 weeks vs baseline of dry eye symptoms were statistically significant as compared to noncompliant patients.

CONCLUSION

Dietary supplementation with Brudypio(®) may be a clinically valuable additional option for the treatment of dry eye syndrome in patients with glaucoma using antiglaucoma eye drops. These results require confirmation with an appropriately designed randomized controlled study.

Lipid-Based Therapy for Ocular Surface Inflammation and Disease

Ocular surface diseases such as dry eye, allergic keratoconjunctivitis, and infection are very prevalent conditions and involve ocular surface stress and inflammation. Recently, various lipid-based therapies have been advocated for the modulation of ocular surface inflammation. Here we review the latest developments and challenges of these strategies. These include administration of essential fatty acids, cyclooxygenase (COX) inhibitors and resolvin analogs. Lipids form part of the tear film and are crucial for tear film stability; loss of tear film stability can aggravate ocular surface inflammation. Strategies to replenish tear film lipids - namely, eyelid warming and eye drops containing natural or synthetic lipids - are evaluated. Recent advances in the use of lipids as ocular drug delivery vehicles, antioxidants, and diagnostic markers are discussed.

Structural characteristics of oil-poor dilutable fish oil omega-3 microemulsions for ophthalmic applications

Docosahexaenoic acid (DHA) promotes synthesis of anti-inflammatory prostaglandins and relief of dry eye symptoms. However, topical ophthalmic application of DHA is difficult because of its lipophilic property. Therefore, it is important to develop aqueous-based formulation with enhanced capabilities. Novel, unique water-dilutable microemulsions (MEs) were constructed to allow loading of naturally occurring rigid long-chain triglyceride of DHA (TG-DHA). The TG-DHA serves as solubilizate and as the oil phase, therefore preparation is poor in oil. The structural transformations of MEs upon water dilution were studied by SAXS, viscosity, electrical conductivity, self-diffusion NMR, DSC, cryo-TEM, and DLS techniques. At low water content a new type of water-in-oil (W/O) structure is formed. The glycerol/water phase hydrates the headgroups of surfactants, and the oil solvates their tails, forming "ill-defined bicontinuous domains". Upon further water dilution more structured bicontinuous domains of high viscosity are formed. After additional dilution, the mesophases invert to oil-in-water (O/W) droplets of ∼8nm. In the structures composed of up to 25wt% water, the TG-DHA spaces and de-entangles the surfactant tails. Once the bicontinuous structures are formed, the surfactants and TG-DHA content decrease and their interfacial layer shrinks, leading to entanglement and buildup of viscous non-Newtonian mesophase. Above 70wt% water TG-DHA is embedded in the core of the O/W droplets, and its effect on the droplets' structure is minimal. This new dilutable ill-defined microemulsion can be a potential delivery vehicle for ophthalmic TG-DHA transport.

Effects of chondrocyte-derived extracellular matrix in a dry eye mouse model

PURPOSE

The occurrence of repetitive dry eye is accompanied by inflammation. This study investigated the anti-inflammatory effects of chondrocyte-derived extracellular matrix (CDECM) on the cornea and conjunctiva in a dry eye mouse model.

METHODS

Dry eyes were experimentally induced in 12- to 16-week-old NOD.B10.H2(b) mice (Control) via subcutaneous injections of scopolamine (muscarinic receptor blocker) and exposure to an air draft for 10 days (desiccation stress [DS] 10D group). Tear volume and corneal smoothness were measured at 3, 5, 7, and 10 days after the instillation of PBS (PBS group) or CDECM (CDECM group). The corneas and conjunctivas were sectioned and stained with hematoxylin and eosin (H&E) and periodic acid Schiff (PAS). The expression of inflammatory markers (i.e., tumor necrosis factor-α [TNF-α], matrix metalloproteinase-2 [MMP-2], MMP-9, intercellular adhesion molecule-1 [ICAM-1], and vascular cell adhesion molecule-1 [VCAM-1]) was detected by quantitative real-time (qRT)-PCR and western blotting. All data were statistically processed using SPSS version 18.0.

RESULTS

The instillation of CDECM after the removal of the DS increased tear production by up to 3.0-fold, and corneal smoothness improved to 80% compared to the PBS group (p<0.05). In the CDECM group, the detachment of the corneal epithelial cells was reduced by 73.3% compared to the PBS group, and the conjunctival goblet cell density was significantly recovered to the control levels (p<0.05). The expression of inflammatory factors was decreased in the cornea and conjunctiva of the CDECM group compared to the PBS group.

CONCLUSIONS

These observations suggest that CDECM induced effective anti-inflammatory improvements in the cornea and conjunctiva in this experimental model of dry eye.

Ocular Surface and Tear Film Changes in Older Women Working with Computers

The aim of this work is to investigate changes in the ocular surface (OS) and tear film (TF) by means of questionnaire-based subjective symptoms, TF break-up time, Schirmer test, and TF analysis in women working with computers and to analyze the effects of the oral supplementation with antioxidants/omega 3 fatty acids (A/ω3) in the OS outcomes. Women aged 40–65 years (n = 148) were recruited at the Administrative Offices of Valencia (Spain) and distributed into two age groups, 40–52 years (AGE1; n = 87) and 53–65 years (AGE2; n = 61), and then subdivided according to being (or not) computer users (CUG; NCUG) during the workday. Homogeneous subgroups were randomly assigned (or not) to the daily intake of three pills of A/ω3 for three months. At baseline and at the end of follow-up, personalized interviews and ocular examination were done. Reflex tear samples were collected from the inferior meniscus and processed for a multiplexed particle-based flow cytometry assay to measure proinflammatory molecules. Statistics were performed using the SPSS 15.0 program. The OS pathology was clinically evident in the AGE1-CUG (33%) versus the AGE2-CUG (64%) of women. Significantly higher interleukins-1β and -6 tear levels were found in the AGE1 versus the AGE2 women employees (P = 0.006 and P = 0.001, resp.), as well as in the CUG versus the NCUG (P = 0.001 and P = 0.000, resp.). Supplementation with A/ω3 positively influenced the OS pathology as manifested by the amelioration of the clinical signs/symptoms related to computer uses. Strategies involving a safe environment and oral micronutrient supplements may be managed within eye-care standards in older women.

Topical nutraceutical Optixcare EH ameliorates experimental ocular oxidative stress in rats

PURPOSE

Based on the hypothesis that oral nutraceuticals do not adequately reach all ocular tissues in the anterior segment, we evaluated the ability of a 3% concentration of the ingredients in a topical nutraceutical antioxidant formulation called Optixcare Eye Health (Optixcare EH) to ameliorate oxidative stress in rat models of age-related ocular diseases.

METHODS

Diabetes was induced by tail-vein injection of streptozotocin, and the development of cataracts was monitored by slit lamp. Young rats were exposed to ultraviolet (UV) light, and the reduction in lens glutathione (GSH) levels and increase in 4-hydroxynonenol (4-HNE) were measured. Oxidative stress in the neural retina was generated by exposure of dark-adapted rats to 1,000 lx of light, and oxidative stress markers were measured. Dry eye was induced in rats by twice daily (b.i.d.) subcutaneous scopolamine injections. Topical Optixcare EH was administered b.i.d. and compared in select experiments to the multifunctional antioxidant JHX-4, the topical aldose reductase inhibitor (ARI) Kinostat™, oral Ocu-GLO™, and the topical ocular comfort agents Optixcare Eye Lube, Optixcare Eye Lube + Hyaluron, and Idrop Vet Plus hyaluronic acid.

RESULTS

In diabetic rats, topical ARI treatment prevented cataract formation while the nutraceuticals delayed their development with Optixcare EH>Ocu-GLO. In UV-exposed rats, the reduction of GSH and increase in 4-HNE in the lens were normalized in order JHX-4>Optixcare EH>Ocu-GLO. In the retina, oxidative stress markers were reduced better by oral JHX-4 compared with topical Optixcare EH. In the scopolamine-induced dry-eye rats, tear flow was maintained by Optixcare EH treatment, while none of the comfort agents examined altered tear flow.

CONCLUSIONS

Topical administration of a 3% concentration of the ingredients in Optixcare EH reduces experimentally induced reactive oxygen species in rats exposed to several sources of ocular oxidative stress. In addition, Optixcare EH maintains tear volume in scopolamine-induced dry eye. This suggests that in the anterior segment, the ingredients in Optixcare EH may have clinical potential against ocular oxidative stress.

A metabolomic approach to dry eye disorders. The role of oral supplements with antioxidants and omega 3 fatty acids

PURPOSE

We used nuclear magnetic resonance spectroscopy of hydrogen-1 nuclei ((1)H NMR S) to analyze the metabolic profile of reflex tears from patients with dry eye disorders.

METHODS

We performed a prospective case-control study involving 90 participants: 55 patients diagnosed with dry eye syndrome (DESG) and 35 healthy subjects (control group, CG). From the DESG, two subgroups were formed: mild DES (n=22) and moderate DES (n=33). Participants were prescribed an oral nutraceutic supplementation containing antioxidants and essential polyunsaturated fatty acids to be taken as three capsules per day for 3 months. Reflex tears (20-30 µl) were collected from the tear meniscus of both eyes of each subject with a microglass pipette. Nuclear magnetic resonance (NMR) spectra were acquired with a standard one-dimensional pulse sequence with water suppression; 256 free induction decays were collected into 64,000 data points with 14 ppm spectral width.

RESULTS

Basal tears showed a differential metabolomic profile between groups. Almost 50 metabolites were identified by H cholesterol, N-acetylglucosamine, glutamate, amino-n-butyrate, choline, glucose, and formate were detected before supplementation and choline/acetylcholine after supplementation. The metabolic profile of the tears was statistically different between groups, as well as before and after supplementation.

CONCLUSIONS

Our data indicate that DES induces changes in the tear metabolic profile that can be modified with appropriate oral supplementation with antioxidants and essential polyunsaturated fatty acids.

Unraveling the molecular repertoire of tears as a source of biomarkers: beyond ocular diseases

Proteomics and metabolomics investigations of body fluids present several challenges for biomarker discovery of several diseases. The search for biomarkers is actually conducted in different body fluids, even if the ideal biomarker can be found in an easily accessible biological fluid, because, if validated, the biomarker could be sought in the healthy population. In this regard, tears could be considered an optimum material obtained by noninvasive procedures. In the past years, the scientific community has become more interested in the study of tears for the research of new biomarkers not only for ocular diseases. In this review, we provide a discussion on the current state of biomarkers research in tears and their relevance for clinical practice, and report the main results of clinical proteomics studies on systemic and eye diseases. We summarize the main methods for tear samples analyses and report recent advances in "omics" platforms for tears investigations. Moreover, we want to take stock of the emerging field of metabolomics and lipidomics as a new and integrated approach to study protein-metabolites interplay for biomarkers research, where tears represent a still unexplored and attractive field.