The core mechanism of dry eye disease is inflammation

Association of the Indoor Environment With Dry Eye Metrics

Importance

The ocular surface is continuously exposed to the environment. Although studies have focused on associations between outdoor environmental conditions and dry eye, information on associations between the indoor environment and dry eye is lacking.

Objective

To determine associations between the indoor environment and dry eye.

Design, Setting, and Participants

This prospective cross-sectional study sample of 97 veterans with a wide range of dry eye metrics was recruited from the Miami Veterans Affairs Healthcare eye clinic from October 19, 2017, to August 30, 2018. Dry eye metrics were first evaluated in the clinic, followed by indoor home environmental metrics within 1 week using a handheld particle counter. Data were analyzed from October 19, 2017, to August 30, 2018.

Main Outcomes and Measures

Symptoms of dry eye were assessed with standardized questionnaires. Dry eye signs were assessed via standard examination. Indoor environmental metrics included temperature, humidity, and particulate matter mass and count.

Results

Of the 97 participants included in the analysis, 81 (84%) were men, with a mean (SD) age of 58.2 (11.9) years. Dry eye symptoms were in the moderate range with a mean (SD) Ocular Surface Disease Index (OSDI) score of 31.2 (23.6). Humidity was associated with worse symptoms and signs, including OSDI score (r = 0.30 [95% CI, 0.07-0.49]; P = .01), inflammation (r = 0.32 [95% CI, 0.10-0.51]; P = .01), Schirmer score (r = -0.25 [95% CI, -0.45 to 0.02]; P = .03), eyelid vascularity (r = 0.27 [95% CI, 0.05-0.47]; P = .02), and meibomian gland dropout (r = 0.27 [95% CI, 0.05-0.47]; P = .02). In multivariate analyses, particulate matter of 2.5 μm or less (PM2.5) was associated with dry eye metrics when adjusted for demographic characteristics, comorbidities, medications, and interaction variables. For example, a 1-unit increase in instrumented PM2.5 level was associated with a 1.59 increase in the OSDI score (95% CI, 0.58-2.59; P = .002), a 0.39 reduction in Schirmer score (95% CI, -0.75 to -0.03; P = .04), a 0.07 increase in meibomian gland dropout (95% CI, 0.01-0.13; P = .02), and a 0.06 increase in inflammation (95% CI, 0.02-0.11; P = .009).

Conclusions and Relevance

When adjusting for humidity, this study found that increased particulate matter exposure was associated with worse dry eye metrics. Humidity was positively associated with dry eye metrics, potentially because higher humidity increases microbial growth and particulate matter size and mass.

Associations Between Systemic Omega-3 Fatty Acid Levels With Moderate-to-Severe Dry Eye Disease Signs and Symptoms at Baseline in the Dry Eye Assessment and Management Study

PURPOSE

Omega-3 (n-3) fatty acid supplementation is used to treat systemic inflammatory diseases, but the role of n-3 in the pathophysiology and therapy of dry eye disease (DED) is not definitive. We evaluated the relationship of systemic n-3 levels with signs and symptoms at baseline in the Dry Eye Assessment and Management (DREAM) Study.

METHODS

Blood samples from participants at baseline were analyzed for n-3 and n-6, measured as relative percentage by weight among all fatty acids in erythrocytes. Symptoms were evaluated using the Ocular Surface Disease Index. Signs including conjunctival staining, corneal staining, tear breakup time (TBUT), and Schirmer's test with anesthesia were also evaluated.

RESULTS

There was no correlation between the systemic n-3 levels and DED symptoms. When the associations with signs of DED were assessed, lower DHA levels were associated with higher conjunctival staining, with mean scores of 3.31, 2.96, and 2.82 for low, medium, and high levels of DHA, respectively (linear trend P=0.007). None of the other signs were associated with DHA or the other measures of n-3.

CONCLUSION

Previous studies have found varying results on the role of n-3 supplementation with the signs and symptoms of DED. Among patients with DED enrolled in the DREAM Study, lower systemic n-3 levels were not associated with worse symptoms and most signs of DED.

Simplified Classification of Tear Film Break-Up Patterns and Their Clinicopathological Correlations in Patients With Dry Eye Disease

PURPOSE

To analyze the pathophysiological differences between patients with dry eye disease (DED) having different tear film break-up patterns (TBUPs).

METHODS

This investigative analysis involved 91 eyes of 91 patients with DED who were divided into two groups: those with "dot" break-up pattern (group I) and those with "random" break-up pattern (group II). Clinical severity was evaluated using the Ocular Surface Disease Index (OSDI), Oxford stain score system (OSS) score, and tear film break-up time (TF-BUT). Eighteen patients in group I and 17 patients in group II were selected for sampling of tears and the conjunctiva, and the concentrations of inflammatory cytokines and mucin in the tears and conjunctival tissue were measured.

RESULTS

Thirty-seven patients were classified as group I and 54 patients as group II. Patients in group I had a statistically lower TF-BUT and a higher OSS score than those in group II, whereas the OSDI was not statistically different between the groups. The concentrations of interleukin (IL)-6 and IL-8 were statistically higher in group I than those in group II. Impression cytology showed that the expression of IL-1β and IL-8 was higher in group I, whereas that of other genes was not statistically different.

CONCLUSIONS

We were able to clearly classify patients with DED with different TBUPs into two groups, and each group had different clinical and pathophysiological characteristics. In patients with the dot break-up pattern, the disease was strongly associated with ocular surface inflammation, as opposed to that in patients without this pattern.

An Association Rule Analysis of Combined Acupoints for the Treatment of Patients with Dry Eye Disease

BACKGROUND

Dry eye disease (DED) has a higher incidence in old age and is seen predominantly in females worldwide. Neurosensory abnormalities, ocular surface inflammation and damage, film instability, and hyperosmolarity are major and proven pathologies responsible for a poor quality of life. Tear breakup time and Schirmer's I test are predominantly used for the evaluation of primary outcomes in patients undergoing conventional treatment. A previous meta-analysis of some relevant studies proved that combination of acupoints could be more effective than single acupoint treatment.

OBJECTIVES

The present study aimed to undertake association rule mining and examined the potential kernel acupoint combination in DED treatment constructed from the extracted randomized controlled trials (RCTs) based on a previous meta-analysis.

METHODS

We summarized 32 acupoints as binary data from the 12 eligible RCTs and analyzed them based on the Apriori algorithm.

RESULTS

TE23, BL2, ST2, ST1, EX-HN5, BL1, LI4, ST36, SP6, and KI3 were the 10 most frequently selected acupoints. The major associated rules in combination of acupoints were {TE23, LI4} ≥ {ST1} and {TE23, ST1} ≥ {LI4}, as inferred from 23 association rules.

CONCLUSIONS

For acupuncture treatment of DED, combined TE23, LI4, and ST1 acupoints could be settled as the kernel of acupoint combination.

Changes of tear lipid mediators after eyelid warming or thermopulsation treatment for meibomian gland dysfunction

Meibomian gland dysfunction (MGD) represents a major cause of dry eye and ocular discomfort. Lipid mediators, often termed oxylipins, can be produced enzymatically or non-enzymatically, and may modulate inflammatory processes in MGD. Here, we aimed to assess the longitudinal changes of lipid mediators after various eyelid treatments (eyelid warming and thermopulsation) over 12 weeks. Secondly, we aimed to assess the chirality of mono-hydroxyl lipid mediators from tears of MGD and healthy participants. Tears lipid mediators were extracted from Schirmer's strips and levels were quantified by liquid chromatography mass spectrometry (LC-MS) techniques. We quantified 33 lipid mediators in the tear, 18 of which (including 11-HETE, 20-OH-LTB4, and 15-oxoETE) were reduced significantly after treatment. Changes in concentrations of 10-HDoHE (r = 0.54) and 15-oxoETE (r = 0.54) were correlated to the number of meibomian gland plugs at baseline, so increased severity of MGD was associated with treatment-induced change in lipid mediators. The chiral analysis demonstrated that 5(S)-HETE, 12(S)-HETE, 15(S)-HETE, 14(S)-HDoHE, 17(S)-HDoHE and 11(R)-HETE were produced with significant enantiomeric excess (ee %) in controls compared to patients, due to enantiomer selective enzymatic action, whereas most lipid mediators were racemates in patients, due to dominance of oxidative effects which have no enantiomeric preference. Treatment of MGD restored the concentrations of 15(S)-HETE, 14(S)-HDoHE and 17(S)-HDoHE with significant ee values, suggesting reduction in oxidative action. Overall, MGD therapy reduced pro-inflammatory molecules generated by lipoxygenase and oxidative stress.

Changes in tear film osmolarity after 25G+ PPV

Background

The aim of our study was to assess changes of tear film osmolarity after micro-incision 25G+ pars plana vitrectomy (PPV) in a prospective study.

Methods

The group consisted of 21 patients (17 women, 4 men) with an average age of 70,52 years [48; 85]. All patients underwent 25G + PPV surgery due to a disorder of the vitreomacular interface (macular hole or epimacular membrane). Only patients who did not use artificial tears before the surgery and who had not been diagnosed with dry eye syndrome at ours or another institution were included in the study. Except cataract surgery, all ocular surface diseases, intraocular diseases, trauma or surgery were exclusion criterias.

Tear film osmolarity was measured in both eyes in every patient before surgery, 10 days after surgery and 30 days after surgery. A paired test was used for statistical evaluation.

Results

No statistically significant change in osmolarity was found in the operated eyes (p > 0.05). No statistically significant changes in time (p > 0.05) were found when both eyes were compared. There were no postoperative complications or failure to observe the study protocol.

Conclusion

Micro-incision 25G + PPV does not affect the osmolarity of the tear film.

In Vivo Anti-Inflammation Potential of Aster koraiensis Extract for Dry Eye Syndrome by the Protection of Ocular Surface

Dry eye syndrome (DES) is a corneal disease often characterized by an irritating, itching feeling in the eyes and light sensitivity. Inflammation and endoplasmic reticulum (ER) stress may play a crucial role in the pathogenesis of DES, although the underlying mechanism remains elusive. Aster koraiensis has been used traditionally as an edible herb in Korea. It has been reported to have wound-healing and inhibitory effects against insulin resistance and inflammation. Here, we examined the inhibitory effects of inflammation and ER stress by A. koraiensis extract (AKE) in animal model and human retinal pigmented epithelial (ARPE-19) cells. Oral administration of AKE mitigated DE symptoms, including reduced corneal epithelial thickness, increased the gap between lacrimal gland tissues in experimental animals and decreased tear production. It also inhibited inflammatory responses in the corneal epithelium and lacrimal gland. Consequently, the activation of NF-κB was attenuated by the suppression of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). Moreover, AKE treatment ameliorated TNF-α-inducible ocular inflammation and thapsigargin (Tg)-inducible ER stress in animal model and human retinal pigmented epithelial (ARPE-19) cells. These results prove that AKE prevents detrimental functional and histological remodeling on the ocular surface and in the lacrimal gland through inhibition of inflammation and ER stress, suggesting its potential as functional food material for improvement of DES.

sPLA2-IIa participates in ocular surface inflammation in humans with dry eye disease

PURPOSE

To determine the roles of secretory phospholipase A2-IIa (sPLA₂-IIa) in the inflammatory responses of the compromised ocular surface.

METHODS

Conjunctival impression cytology (IC) samples and tears were collected from patients with mild to severe non-Sjogren's dry eye disease (DED) and normal controls. The IC samples were analyzed for transcription of sPLA₂-IIa and inflammatory cytokine/chemokine genes using quantitative real-time RT-PCR (qRT²-PCR) and pathway-focus PCR-array. The tear samples were analyzed for 13 inflammatory cytokines and chemokines with Millipore 13-Plex kit. Finally, sPLA2-IIa-treated human conjunctival epithelial cell (HCjE) cultures were analyzed with a pathway-focused PCR array.

RESULTS

Transcription of sPLA2-IIa was significantly increased in severe DED patients as compared to those of mild DED patients and normal controls. The transcription of inflammatory cytokines (IL-1β, IL-4, IL-6, IL-17, TNF-α, IFN-γ), chemokines (IL-8, CXCL10, CXCL11, CXCL-14, CCR6, LTB) and matrix metalloproteinase 9 (MMP9) were simultaneously increased in the same IC samples of DED. Concentrations of IL-6 and IL-8 in tears were significantly higher in DED patients than those of the controls and positively correlated to DED severity scores. On the other hand, IL-2, IL-4, IL-10, IL-12 and IFN-γ were significantly lower in DED patients than those in the controls and inversely correlated to DEWS scores. Single treatment of sPLA2-IIa, IL-1β or TNF-α of HCjE cells induced minimal to no PGE2 production. When sPLA2-IIa was added to HCjE cells that were pre-treated with pro-inflammatory cytokines (TNF-α or IL-1β), significant stimulation of PGE2 production was observed, concurrent with the extensive transcriptional changes of many inflammatory cytokines/chemokines and their receptors.

CONCLUSION

sPLA₂-IIa activity was elevated and not only associated with inflammatory changes in DED patient samples, but was also found to cooperate with TNF- α and IL-1β to induce inflammatory response in human conjunctival epithelial cells. Understanding the roles of sPLA₂-IIa in ocular surface inflammation may lead to better strategies for the treatment of chronic inflammation associated with DED and other ocular inflammatory conditions.

Cluster Analysis of Dry Eye Disease Models Based on Immune Cell Parameters - New Insight Into Therapeutic Perspective

Dry eye disease (DED) can be represented as a display of disease in the mucosal part of the eye. It is quite distinct from the retinal side of the eye which connects with the neurons and thus represents the neuroimmunological disease. DED can occur either by the internal damage of the T cells inside the body or by microbial infections. Here we summarize the most common animal model systems used for DED relating to immune factors. We aimed to identify the most important immune cell/cytokine among the animal models of the disease. We also show the essential immune factors which are being tested for DED treatment. In our results, both the mechanism and the treatment of its animal models indicate the involvement of Th1 cells and the pro-inflammatory cytokine (IL-1β and TNF-α) related to the Th1-cells. The study is intended to increase the knowledge of the animal models in the field of the ocular surface along with the opening of a dimension of thoughts while designing a new animal model or treatment paradigm for ocular surface inflammatory disorders.

NLRP12- and NLRC4-mediated corneal epithelial pyroptosis is driven by GSDMD cleavage accompanied by IL-33 processing in dry eye

PURPOSE

Dry eye disease (DED) is a common and multifactor-induced autoimmune ocular surface disease. Environmental factors, such as desiccating stress (DS) and hyperosmolarity, affect the corneal epithelium to induce ocular surface inflammation in DED. We aimed to explore the potential mechanisms by which innate immunity and pyroptosis are initiated in the mucosal epithelium in response to environmental stress.

METHODS

Experimental dry eye was established in C57BL/6 J mice and genetic mice on the background of C57BL/6 J mice by subcutaneous injection of scopolamine and exposure to a desiccating environment. SDHCEC cell line was subjected to hyperosmolarity stress (450 mOsM). The phenol red thread tear test and corneal epithelial defects evaluation were used as assessments of severity of DED. RNA-sequencing, quantitative real-time PCR, western blotting and immunofluorescence staining were performed in this study.

RESULTS

Loss-of-function studies indicated that genetic deletion of GSDMD alleviates DS-induced corneal epithelium defects, and GSDMD is needed for IL-33 processing. We further found that NLRP12 collaborates with NLRC4 inflammasome to initiate GSDMD-dependent pyroptosis, which requires TLR4-induced caspase-8 (CASP8) activation in the mucosal corneal epithelium in response to DS.

CONCLUSIONS

These findings provide compelling evidence that GSDMD-dependent pyroptosis plays a pivotal role in DED. A novel mechanism involving NLRP12 and NLRC4 inflammasomes-induced GSDMD-dependent pyroptosis, accompanied by IL-33 processing is responsible for ocular surface epithelial defects in response to environmental stress. GSDMD is required for IL-33 processing and the subsequent amplification of inflammatory cascades. These findings reveal novel therapeutic targets for treating DED.

Carboxymethyl Cellulose-Coated Tacrolimus Nonspherical Microcrystals for Improved Therapeutic Efficacy of Dry Eye

Dry eye (DE) is a highly prevalent ocular surface disease which affects the quality of life and results in low working efficiency. Frequent instillation is required due to low bioavailability of conventional eye drops. The aim of this study is to develop a novel formulation of tacrolimus (TAC), routinely prescribed for DE, by combination of the microcrystal technology and layer-by-layer assembly. First, nonspherical tacrolimus microcrystals (TAC MCs) are synthesized by antisolvent-induced precipitation. These TAC MCs are modified by alternate deposition of poly(allylamine hydrochloride) (PAH) and carboxymethyl cellulose (CMC) subsequently to obtain CMC-coated TAC MCs (TAC-(PAH/CMC)₃ ). The resultant formulations are evaluated in vivo in a mouse DE model induced by an intelligently controlled environmental system. Compared with commercially available TAC eye drops and the TAC MCs counterpart, TAC-(PAH/CMC)₃ exhibits superior therapeutic performance with reduced drug instillation frequency, which is attributed to the nonspherical geometry of MCs, the lubricant, mucoadhesive effect of CMC, and the anti-inflammatory function of TAC. Therefore, TAC-(PAH/CMC)₃ represents a better option for the management of DE.

Dry Eye in Systemic Sclerosis Patients: Novel Methods to Monitor Disease Activity

Background: In systemic sclerosis (SSc) patients, dry eye syndrome (DES) is the most frequent ocular feature. The aim of this study was to investigate ocular DES-related SSc patients and to establish any correlation with the severity of the disease. Methods: Retrospectively, data from 60 patients with SSc underwent ophthalmic examination, where non-invasive film tear break-up time (NIF-TBUT), tear film lipid layer thickness (LLT), anesthetic-free Schirmer test I, tear osmolarity measurement (TearLab System), and modified Rodnan skin score (mRSS) data were collected. The visual analog scale (VAS) and Symptom Assessment in Dry Eye (SANDE) methods were utilized. The results were correlated with mRSS and the duration of SSc. Results: Severe DES occurred in 84% of cases, and was more severe in women. The eyelids were involved in 86.6%, secondary to meibomian gland disease (MGD). A direct correlation was found between the tear osmolarity (mean 328.51 ± 23.8 SD) and skin score (mRSS) (r = 0.79; p < 0.01). Significantly reduced NIF-TBUT, LLT, and Schirmer test I values were observed in the case of severe skin involvement. Conclusions: SSc patients show lipid tear dysfunction related to the severity and duration of the disease due to inflammation and the subsequent atrophy of the meibomian glands.

Cationic Emulsion-Based Artificial Tears as a Mimic of Functional Healthy Tear Film for Restoration of Ocular Surface Homeostasis in Dry Eye Disease

Dry eye disease (DED) is a complex multifactorial disease that affects an increasing number of patients worldwide. Close to 30% of the population has experienced dry eye (DE) symptoms and presented with some signs of the disease during their lifetime. The significant heterogeneity in the medical background of patients with DEs and in their sensitivity to symptoms renders a clear understanding of DED complicated. It has become evident over the past few years that DED results from an impairment of the ocular surface homeostasis. Hence, a holistic treatment approach that concomitantly addresses the different mechanisms that result in the destabilization of the tear film (TF) and the ocular surface would be appropriate. The goal of the present review is to compile the different types of scientific evidence (from in silico modeling to clinical trials) that help explain the mechanism of action of cationic emulsion (CE)-based eye drop technology for the treatment of both the signs and the symptoms of DED. These CE-based artificial tear (AT) eye drops designed to mimic, from a functional point of view, a healthy TF contribute to the restoration of a healthy ocular surface environment and TF that leads to a better management of DE patients. The CE-based AT eye drops help restore the ocular surface homeostasis in patients who have unstable TF or no tears.

The Immunological Basis of Dry Eye Disease and Current Topical Treatment Options

Homeostasis of the lacrimal functional unit is needed to ensure a well-regulated ocular immune response comprising innate and adaptive phases. When the ocular immune system is excessively stimulated and/or immunoregulatory mechanisms are disrupted, the balance between innate and adaptive phases is dysregulated and chronic ocular surface inflammation can result, leading to chronic dry eye disease (DED). According to the Tear Film and Ocular Surface Society Dry Eye Workshop II definition, DED is a multifactorial disorder of the ocular surface characterized by impairment and loss of tear homeostasis (hyperosmolarity), ocular discomfort or pain, and neurosensory abnormalities. Dysregulated ocular immune responses result in ocular surface damage, which is a further contributing factor to DED pathology. Several therapeutics are available to break the vicious circle of DED and prevent chronic disease and progression, including immunosuppressive agents (steroids) and immunomodulators (cyclosporine and lifitegrast). Given the chronic inflammatory nature of DED, each of these agents is commonly used in clinical practice. In this study, we review the immunopathology of DED and the molecular and cellular actions of current topical DED therapeutics to inform clinical decision making.

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.

Effect of a formulated eye drop with Leptospermum spp honey on tear film properties

Aim

To evaluate the effects of a proprietary formulated eye drop with Leptospermum spp honey versus a conventional lubricant eye drop on tear film properties in subjects with symptoms related to dry eye disease after 28 days of treatment.

Methods

Forty-six subjects with symptoms related to dry eye (Ocular Surface Disease Index (OSDI) score >12) were enrolled and randomly assigned to receive either the test formulated eye drop (Optimel by Melcare Biomedical Pty Ltd) or control eye drops (Alcon, USA) in this double-masked study. Inferior lipid layer thickness (LLT), tear film evaporation rate (TER), fluorescein tear film break-up time (TBUT), corneal staining and subjective symptoms (OSDI and visual analogue scales (VAS)) were measured before and after 28 days of instilling the eye drops.

Results

Forty-two subjects completed the study (21 subjects in each group). After 28 days of treatment, TER showed a significantly greater reduction with the formulated eye drop compared with the control (p=0.01). TBUT showed a slight but not statistically significant increase with the formulated eye drop compared with the control (p=0.06), and a significantly greater reduction (improvement) in OSDI scores was observed with the formulated eye drop compared with the control (p=0.01). No significant differences were found between the two groups for inferior LLT, corneal staining and any of the VAS scores.

Conclusions

The formulated eye drops were effective in reducing tear film evaporation rate and were more effective for improving symptoms of dry eye compared with the control eye drops after 28 days of treatment.

Trial registration number

NCT03622619.

The Key Role of VEGF in the Cross Talk between Pterygium and Dry Eye and Its Clinical Significance

PURPOSE

To examine whether dry eye severity is a risk factor for pterygium activity and whether vascular endothelial growth factor (VEGF) is crucial in the cross talk between pterygium and dry eye.

METHODS

A total of 103 patients with primary pterygium (Pteg) were included in the study group; they were divided into 2 groups according to the complication of dry eye (DE) (Pteg + DE group, Pteg - DE group). Further, 60 patients with just dry eye (DE group) and 60 normal individuals (normal) were included as 2 control groups. DE severity and pterygium activity were measured, and unstimulated tear samples and pterygium tissues were collected for cytokine detection.

RESULTS

(1) Tear detection: VEGF expression increased in the Pteg + DE group compared to the Pteg - DE, DE, and normal control groups; VEGF was especially increased in the active Pteg + DE group. VEGF concentration was positively correlated with pterygium activity. (2) Tissue detection: the mRNA expression of VEGF was upregulated in the active pterygium group.

CONCLUSIONS

Inflammation played an important role in the development of dry eye and pterygium. VEGF was the core molecule in the cross talk, which might explain the high incidence of the coexistence of these 2 diseases.

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.

Conjunctival HLA-DR Expression and Its Association With Symptoms and Signs in the DREAM Study

Purpose

Evaluation of dry eye disease (DED) relies on subjective symptoms and signs. We examined HLA-DR expression (HLA-DR%) in conjunctival cells, a minimally invasive biomarker with objective metrics, as an alternative method.

Methods

Dry Eye Assessment and Management (DREAM) study participants completed the Ocular Surface Disease Index questionnaire. Clinicians evaluated tear volume, tear breakup time, and corneal and conjunctival staining. Conjunctival impression cytology samples (n = 1049) were assessed for HLA-DR% in total cells (TCs), epithelial cells (ECs), and white blood cells (WBCs). Associations (categorized into <5%, 5%–15%, >15%–25%, and >25%) with symptoms and signs were evaluated.

Results

The HLA-DR% varied markedly across samples. Over 40% had <5 HLA-DR% positive cells in TCs and ECs and under 23% in WBCs. Higher HLA-DR% was associated with higher conjunctival staining for ECs (mean score 2.77 for <5% and 3.28 for >25%, linear trend P = 0.009) and TCs (mean score 2.82 for <5% and 3.29 for >25%, linear trend P = 0.04) and in TCs was associated with higher corneal staining (mean score 3.59 for <5% and 4.46 for >25%, linear trend P = 0.03). HLA-DR% in WBCs did not correlated with signs (all P ≥ 0.58), and in TCs, ECs or WBCs were not associated with symptoms (P> 0.06).

Conclusions

The distribution of HLA-DR% in conjunctival cells reflects the heterogeneity of disease in DREAM participants. High percentages of samples with <5% positive cells indicate that HLA-DR% may not be a sensitive marker for DED in all patients.

Translational Relevance

High HLA-DR% in ECs in association with high conjunctival staining may identify a subgroup of DED patients prone to epithelial disease and possibly need a different approach from current standards of treatment.

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.

Dry Eye Disease: A Review of Epidemiology in Taiwan, and its Clinical Treatment and Merits

Dry eye disease (DED) has become common on a global scale in recent years. There is a wide prevalence of DED in different countries based on various ethnicities and environment. DED is a multifactorial ocular disorder. In addition to advanced age and gender, such factors as living at high altitude, smoking, pterygium, prolonged use of consumer electronics or overingesting of caffeine or multivitamins are considered to be the major risk factors of DED. We report the DED epidemiology in Taiwan firstly in this article. According to the pathophysiological factors and changes inthe composition of the tear film in DED, it can be categorized into several subtypes, including lipid anomaly dry eye, aqueous tear deficiency, allergic and toxic dry eye among others. Each subtype has its own cause and disease management; therefore, it is important for ophthalmologists to identify the type through literature review and investigation. The management of DED, relies not only on traditional medications such as artificial tears, gels and ointments, but also newer treatment options such as acupuncture, SYL1001, and nanomedicine therapy. We also conducted a comprehensive literature review including common subtypes and treatment of DED. Clearly, more clinical trials are needed to assess the efficacy and safety of the various treatments and common subtypes of DED.

Trehalose augments autophagy to mitigate stress induced inflammation in human corneal cells

PURPOSE

Cornea acts as a structural barrier and protects the eye from environmental stresses. Inflammation in ocular surface causes discomfort and visual distortion. Defective autophagy has been associated with inflammation and ocular surface diseases. Therefore, we explored the protective role of trehalose on inflammation and desiccation-triggered stress in human corneal cells in vitro and in dry eye patients.

METHOD

TNF-α and desiccation stress induced human corneal cells (piHCF and HCE-T) with or without trehalose treatment were analyzed for the expression levels of inflammatory and autophagy related markers by qPCR, western blotting, multiplex ELISA and fluorescence imaging. Dry eye patients (N = 9) were enrolled and administered with trehalose in one eye and carboxymethylcellulose (CMC) in the contralateral eye (B.I.D, for 30 days). Dry eye signs OSDI, TBUT, Schirmer's Test, and tear cytokines were measured in dry eye patient's pre and post treatment.

RESULTS

Cells treated with trehalose exhibits increased levels of autophagy markers LC3II and LAMP1 compared to untreated cells. Trehalose reduced the mRNA and secreted cytokines levels of IL-6, IL-8 and MCP-1 in corneal cells under TNF-α and desiccation stress mediated inflammation compared to controls. Further, trehalose reduced stress driven p38 phosphorylation in corneal cells. Additionally, topical administration of trehalose alleviated the clinical symptoms and tears cytokine levels in dry eye patients compared to CMC.

CONCLUSION

Trehalose reduces stress induced inflammation through p38MAPK inhibition and autophagy activation. The anti-inflammatory mechanism of trehalose was independent to NFκB pathway. Further, topical administration of trehalose ameliorated dry eye associated symptoms and associated tear cytokines levels.

Efficacy and Safety of Topical Chloroquine in Mild to Moderate Dry Eye Disease

Purpose: To evaluate the role of topical chloroquine (CHQ) as an adjunct to topical lubricants in the management of mild-moderate dry eye disease (DED)Methods: Prospective comparative pilot study allocated 150 patients with symptoms of mild to moderate DED to receive topical CMC 0.5% three times a day (group I, n = 75) or topical CHQ 0.03% twice a day with carboxymethylcellulose (CMC) 0.5% three times a day (group II, n = 75), for three months. Primary outcome measures were ocular surface disease index (OSDI) score and conjunctival impression cytology at 3 months. Secondary outcome measures were TBUT, Schirmer's test, ocular surface staining and any adverse effects at 3 months. Follow up was performed at 1 and 3 months.Results: At three months, the OSDI score was significantly better in the CHQ group as compared with the CMC group (CMC-18.36 ± 4.03 (SD), CHQ group- 15.9 ± 5.18 (SD); p = .002). Nelson's score was 0.92 ± 0.69 (SD) in the CHQ group as compared with 1.60 ± 0.77 (SD) in the CMC group (p < .001). Abnormal impression cytology was observed in 20% cases in the CHQ group as compared with 61.3% cases in CMC group (p < .001). A significant correlation was observed between Nelson's score and OSDI (Spearman's rho correlation coefficient 0.414, p < .001). TBUT, Schirmer test and ocular surface staining were significantly better in the CHQ group (p < .001). No adverse effects were observed in any group.Conclusion: Topical chloroquine is a useful adjunct to topical lubricants in the management of DED as it decreases the underlying chronic inflammation and helps maintain ocular surface stability.

Tear Film-Oriented Diagnosis and Tear Film-Oriented Therapy for Dry Eye Based on Tear Film Dynamics

In December 2010 and January 2012, 3% diquafosol sodium ophthalmic solution and 2% rebamipide ophthalmic suspension, respectively, appeared first in Japan as prescription drugs for the treatment of dry eye (DE). Since then, not only the diagnosis and treatment but also the understanding of the pathophysiology of DE have greatly advanced, and a new concept of layer-by-layer diagnosis and treatment for DE, respectively termed "tear-film-oriented diagnosis" (TFOD) and "tear-film-oriented therapy" (TFOT) was born. This new concept is currently in the process of expanding from Japan to other Asian countries. TFOD is the method used for the differential diagnosis of DE, which includes aqueous-deficiency DE (ADDE), decreased wettability DE (DWDE), and increased evaporation DE (IEDE), through the dynamics of tear film (TF) and breakup patterns (BUPs) after the eye is opened. BUPs and/or each diagnosed DE subtype are/is able to distinguish the insufficient components of the ocular surface that are responsible for each BUP in a layer-by-layer fashion. Aqueous fluid, membrane-associated mucins (especially MUC16), and the lipid layer and/or secretory mucins must be insufficient in ADDE, DWDE, and IEDE, respectively, and this allows for a layer-by-layer treatment to be proposed for each BUP via the supplementation of the insufficient components, using the topical therapy currently available. In Japan, TF breakup is regarded as a visible core mechanism for DE, and an abnormal breakup time (i.e., ≤5 seconds) and symptoms are currently used for the diagnosis of DE. Therefore, TFOD and TFOT could be an ideal and practical pathway for clinicians to manage DE.

Efficacy of Omega-3 Fatty Acid Supplementation for Treatment of Dry Eye Disease: A Meta-Analysis of Randomized Clinical Trials

PURPOSE

To assess whether omega-3 fatty acid (FA) supplementation is more efficacious than placebo in amelioration of signs and symptoms of dry eye disease.

METHODS

We performed a systematic literature search in PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials databases. We included randomized clinical trials comparing omega-3 FA supplementation with placebo in patients with dry eye disease. The outcome measures were dry eye symptoms, breakup time (BUT), Schirmer test, and corneal fluorescein staining. The pooled effect sizes were estimated using a random-effects model. Heterogeneity was evaluated using the Q and I tests. Sensitivity analysis and assessment of publication bias were performed. Meta-regression was performed to evaluate the source of heterogeneity.

RESULTS

Seventeen randomized clinical trials involving 3363 patients were included. Compared with placebo, omega-3 FA supplementation decreased dry eye symptoms [standardized difference in mean values (SDM) = 0.968; 95% confidence interval (CI) 0.554-1.383; P < 0.001] and corneal fluorescein staining (SDM = 0.517; 95% CI, 0.043-0.991; P = 0.032), whereas it increased the BUT (SDM = 0.905; 95% CI, 0.564-1.246; P < 0.001) and Schirmer test values (SDM = 0.905; 95% CI, 0.564-1.246; P < 0.001). No evidence of publication bias was observed, and sensitivity analyses indicated the robustness of results obtained. Meta-regression analysis showed a higher improvement of dry eye symptoms and BUT in studies conducted in India.

CONCLUSIONS

This meta-analysis provides evidence that omega-3 FA supplementation significantly improves dry eye symptoms and signs in patients with dry eye disease. Therefore, our findings indicate that omega-3 FA supplementation may be an effective treatment for dry eye disease.

Tear osmolarity after cataract surgery

Purpose

To evaluate the changes in tear film osmolarity and Schirmer I test after cataract surgery.

Methods

This single-center, prospective study included patients with no subjective complaints about dry eye disease. Patients with the following conditions were excluded: contact lens wearers, patients with diabetes, pseudoexfoliation, pterygia, and eye drops users. The eye that had not undergone surgery was considered the control group. Tear osmolarity and Schirmer I test were evaluated before surgery and during the first postoperative month.

Results

Thirty-seven patients were enrolled in the study. Before surgery, tear osmolarity was 301.2 ± 15.09 Osm/L in the study group and 302.3 ± 14.21 mOsm/L in the control group (P = 0.2), while Schirmer I test averaged 13.4 ± 10.50 mm in the study group and 13.7 ± 10.79 mm in the control group (P = 0.6). The next morning, the tear osmolarity decreased to <275 mOsm/L in the study group while in the control group, the value increased to 303.1 mOsm/L ± 13.68 (P = 0.008). The Schirmer I test in the same morning showed an increase up to 19.9 ± 9.73 mm in the study group and to 15.7 ± 10.19 mm in the control group (P = 0.01). One week later, the tear osmolarity increased to 311.8 ± 14.85 mOsm/L, while the control group averaged 301.7 ± 11.84 mOsm/L (P = 0.013). The Schirmer I test results decreased to 15.8 ± 9.37 mm in the study group and 13.9 ± 10.19 mm in the control group (P = 0.07) one week after the surgery. One month after surgery, tear osmolarity and Schirmer I test results in the study group decreased to the control group level (P > 0.05).

Conclusions

The tear osmolarity results increased to the dry eye disease level in the first postoperative week. Over the course of one month, the difference in tear osmolarity and Schirmer I test values for the study and control groups leveled off.

TRPV1 and TRPM8 Channels and Nocifensive Behavior in a Rat Model for Dry Eye

Purpose

Persistent ocular surface pain occurs in moderate to severe dry eye disease (DE); however, the mechanisms that underlie this symptom remain uncertain. The aim of this study was to determine if the transient receptor potential vanilloid ion channels play a role in hypertonic saline (HS)-evoked corneal reflexes in a model for aqueous tear deficient DE.

Methods

Eye wipe behavior and orbicularis oculi muscle activity (OOemg) were measured after ocular instillation of HS, capsaicin, or menthol 14 days after exorbital gland removal. Total RNA and protein were measured from anterior eye segment and trigeminal ganglia of sham and DE rats.

Results

Eye wipe behavior was enhanced in DE rats after HS and capsaicin instillation, but not after menthol when compared to sham rats. DE rats displayed greater OOemg activity after HS and capsaicin, but not after menthol, compared to sham rats. HS-evoked OOemg activity was reduced by selective TRPV1 antagonists and by coapplication of capsaicin plus QX-314, a charged lidocaine derivative. Menthol did not affect OOemg activity; however, selective antagonism of TRPM8 reduced HS-evoked OOemg activity. TRPV1 protein levels were increased in anterior eye segment and trigeminal ganglion samples from DE rats, whereas TRPM8 levels were not affected.

Conclusions

These results suggest that TRPV1 plays a significant role in mediating enhanced nocifensive behavior in DE, while TRPM8 may play a lesser role. Strategies to target specific transducer molecules on corneal nerves may prove beneficial as adjunct therapies in managing ocular pain in moderate to severe cases of DE.

Modulation of Inflammation-Related Genes in the Cornea of a Mouse Model of Dry Eye upon Treatment with Cyclosporine Eye Drops

Purpose/Aim: Inflammation is recognized as playing an etiological role in dry eye disease. This study aimed to assess the efficacy of various topical cyclosporine A (CsA) formulations on cornea inflammatory markers in a mouse model of dry eye.

MATERIAL AND METHODS

Six- to 7-week-old mice treated with scopolamine were housed in a controlled environment room to induce dry eye. Following dry eye confirmation by corneal fluorescein staining (CFS), the mice were treated three times a day with: 0.05%CsA (Restasis, Allergan), 0.1%CsA (Ikervis, Santen), 1%CsA oil solution, and 0.5% loteprednol etabonate (LE, Lotemax, Baush+Lomb), or left untreated. Aqueous tear production and CFS scores were assessed during the treatment period, and corneas were collected to measure the expression profile of a selection of inflammatory genes.

RESULTS

After 7 days of treatment, the CFS scores were reduced by 21%, 31%, and 44% with 0.05%CsA, 0.1%CsA, and 1%CsA eye drops, respectively. By contrast, 0.5% LE did not decrease corneal fluorescein staining at day 10. A statistically significant dose-dependent CFS reduction was observed only between the 0.05% and 1%CsA formulations. The gene expression profiles indicated that 12, 18, 17 genes were downregulated by 0.05%CsA, 0.1%CsA, 1%CsA, respectively. Among them, the genes significantly downregulated were: IL1A, IL1R1, and TLR4 with 0.05%CsA; H2-Eb1, IL1A, IL1B, IL1RN, IL6, TGFB2, TGFB3, TLR2, TLR3, and TLR4 with 0.1%CsA; IL1B, IL6, TGFB3, and TLR4 with 1%CsA. TGFB1 and TGFBR1 were the only genes upregulated in all groups, but only TGFB1 upregulation reached significance. IL6RA was significantly upregulated by 0.05%CsA.

CONCLUSIONS

This study indicates that the three CsA formulations effectively modulated TLR4, TGFβ1, IL1, and IL6 pathways to reduce corneal epithelium lesions in a mouse model of severe dry eye. The study also suggests that the different anti-inflammatory eye drops modulated inflammatory genes in a slightly different manner.

Tear Biomarkers in Dry Eye Disease

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The Role of SKQ1 (Visomitin) in Inflammation and Wound Healing of the Ocular Surface

Introduction

SkQ1 (Visomitin) is a novel mitochondrial-targeted antioxidant that holds promise in the treatment of inflammation associated with ocular surface diseases such as dry eye disease (DED) and corneal wounds. However, the specific role of SkQ1 in ocular surface epithelial tissue has yet to be explicated. The goal of this study is to identify roles of SkQ1 in conjunctival inflammation and corneal wound healing.

Methods

To determine the role of SkQ1 in inflammation, human conjunctival epithelial (HCjE) cell cultures were sensitized with pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) followed by treatments with SkQ1. The production of inflammatory biomarker prostaglandin E2 (PGE2) and cell viability were quantitatively evaluated. To determine the role of SkQ1 in wound healing, human corneal limbus epithelial (HCLE) cell cultures were streaked to create wounds. The wound closure times, ability to support single HCLE cell proliferation and changes of cell migration in the presence of SB203580, an inhibitor of p38 mitogen-activated protein kinase (MAPK), were further compared.

Results

The HCjE and HCLE cultures showed no apparent cytotoxicity to SkQ1 in concentrations up to 250 nM (HCjE) or 2500 nM (HCLE). The HCLE cultures showed no toxicity to SkQ1 at all the SkQ1 concentrations tested. SkQ1 significantly suppressed PGE2 production of HCjE at concentrations < 300 nM (24 h) and 50 nM (48 h), apparently being SkQ1 dose and treatment time dependent. The wound closure rates were increased by 4% in 4 h and by 9% after 8–12 h in the presence of 50 nM SkQ1. Furthermore, as little as 25 nM of SkQ1 significantly stimulated HCLE single-cell proliferation. Lastly, the SkQ1-stimulated wound healing was completely abolished by SB203580.

Conclusion

Results of the current study demonstrate that SkQ1 exhibits an anti-inflammatory role and can be safely applied to ocular surface epithelium up to a concentration of 300 nM (181 ng/ml) for 24 h. SkQ1 also significantly enhances corneal epithelial wound healing, likely through enhancement of cell proliferation and migration. The data provide solid support for SkQ1 as a promising new therapeutic strategy for treatment of conjunctival inflammation as well as corneal wounds.

Funding

This study was sponsored by Mitotech SA Pharmaceuticals.

Electronic supplementary material

The online version of this article (10.1007/s40123-018-0158-2) contains supplementary material, which is available to authorized users.

Association between dry eye disease and asthma: a nationwide population-based study

BACKGROUND

Dry eye disease (DED), a chronic ocular disease, is associated with numerous medical issues, including asthma. However, studies on these associations are limited. In this study, we investigated the incidence of DED among patients with asthma and its correlation with other allergic comorbidities.

METHODS

We retrospectively analyzed data from the National Health Insurance Research Database of Taiwan. We compared the data of 41,229 patients with asthma with those of 164,916 sex- and age-matched non-asthma controls. We followed up the patient and control groups from 1998 to 2010, and compared the rate of DED in these two groups. We further analyzed the allergic comorbidities and asthma-related medication use among the patients with asthma to verify whether these factors were associated with DED.

RESULTS

The patients in the asthma group were more likely to have DED than were the controls (6.35% vs. 4.92%, p < 0.0001). In the asthma group, female had a higher risk of DED (odds ratio (OR) = 1.70, 95% confidence interval (CI) [1.57-1.85]) than males did. After adjustment for sex, age, income, urbanization, and the other two allergic comorbidities, patients with allergic rhinitis (adjusted OR = 1.58, 95% CI [1.46-1.72]) and urticaria (adjusted OR = 1.25, 95% CI [1.12-1.38]) were more likely to have DED, but not patients with atopic dermatitis (adjusted OR = 1.17, 95% CI [0.98-1.40]). Patients with asthma who had prescriptions of leukotriene receptor antagonists (LTRAs) (adjusted OR = 1.29, 95% CI [1.01-1.64]), oral antihistamines (adjusted OR = 2.02, 95% CI [1.84-2.21]), and inhaled corticosteroids (adjusted OR = 1.19, 95% CI [1.04-1.36]) exhibited association with DED.

DISCUSSION

Our findings reveal that patients with asthma-particularly females-were more likely to have DED, with comorbidities such as allergic rhinitis and urticaria, and prescriptions including LTRAs, antihistamines, and inhaled corticosteroids. The results suggest that in clinical practice, physicians should pay attention to DED, particularly in patients with a high risk of DED.

Reconsidering the central role of mucins in dry eye and ocular surface diseases

Mucins are key actors in tear film quality and tear film stability. Alteration of membrane-bound mucin expression on corneal and conjunctival epithelial cells and/or gel-forming mucin secretion by goblet cells (GCs) promotes in ocular surface diseases and dry eye disease (DED). Changes in the mucin layer may lead to enhanced tear evaporation eventually contributing to tear hyperosmolarity which has been associated with ocular surface inflammation. Inflammatory mediators in turn may have a negative impact on GCs differentiation, proliferation, and mucin secretion. This sheds new light on the position of GCs in the vicious circle of DED. As contributor to ocular surface immune homeostasis, GC loss may contribute to impaired ocular surface immune tolerance observed in DED. In spite of this, there are no tools in routine clinical practice for exploring ocular surface mucin deficiency/dysregulation. Therefore, when selecting the most appropriate treatment options, there is a clear unmet need for a better understanding of the importance of mucins and options for their replacement. Here, we comprehensively revisited the current knowledge on ocular surface mucin biology, including functions, synthesis, and secretion as well as the available diagnostic tools and treatment options to improve mucin-associated homeostasis. In particular, we detailed the potential link between mucin dysfunction and inflammation as part of the uncontrolled chronic inflammation which perpetuates the vicious circle in DED.

Phosphosulindac is efficacious in an improved concanavalin A-based rabbit model of chronic dry eye disease

Dry eye disease (DED) currently has no satisfactory treatment partly because of the lack of informative animal models. We evaluated the anti-inflammatory phosphosulindac (PS) for the treatment of DED using a new rabbit model of DED based on the concanavalin A (Con A) acute DED model: we injected all lacrimal glands with Con A weekly under ultrasound guidance, which prolonged DED to >3 weeks, and thoroughly assessed efficacy with tear break-up time (TBUT), tear osmolarity, Schirmer test, and tear lactoferrin levels. Rabbits with DED (n = 8-10 eyes per group) were treated topically with PS or vehicle 3×/day for 21days. PS restored TBUT, tear osmolarity, and lactoferrin levels (P < 0.0001-0.04) to normal but did not significantly improve the results of the Schirmer test. PS showed no side effects and was much more efficacious than cyclosporine or lifitegrast. In the cornea, PS suppressed the activation of nuclear factor kappa-B, the levels of transforming growth factor beta, interleukin-1 beta, interleukin-6, and interleukin-8, and the levels of matrix metalloproteinase (MMP)-1 and MMP-9, and MMP activity. Levels of prostaglandin E₂ (PGE₂) in tears and cornea were preserved in PS-treated rabbits. Ketorolac and diclofenac, two ophthalmic NSAIDs causing corneal melt, nearly completely suppressed PGE₂ levels but had no effect on MMPs. The effects of PS on PGE₂ and MMPs likely account for its apparent ocular safety. Our results establish an animal model for acute and chronic DED suitable for drug efficacy studies and indicate that PS merits evaluation for DED.

Dry Eye Assessment and Management (DREAM©) Study: Study design and baseline characteristics

PURPOSE

Describe trial design and baseline characteristics of participants in the DRy Eye Assessment and Management (DREAM©) Study.

DESIGN

Prospective, multi-center, randomized, double-masked "real-world" clinical trial assessing efficacy and safety of oral omega-3 (ω3) supplementation for the treatment of dry eye disease (DED).

METHODS

RESULTS: Mean age of participants was 58.0 ± 13.2 years. Mean OSDI score at baseline was 44.4 ± 14.2. Mean conjunctival staining score (scale 0-6) was 3.0 ± 1.4, corneal staining score (scale 0-15) was 3.9 ± 2.7, tear break-up time was 3.1 ± 1.5 s, and Schirmer test was 9.6 ± 6.5 mm/5 min.

CONCLUSIONS

DREAM© participants mirror real world patients who seek intervention for their DED-related symptoms despite their current treatments. Results regarding the efficacy of omega-3 supplementation will be helpful to clinicians and patients with moderate to severe DED who are considering omega-3 as a treatment. This trial design may be a model for future RCT's on nutritional supplements and DED treatments seeking to provide useful information for clinical practice.

TRIAL REGISTRATION

ClinicalTrials.gov number NCT02128763.

Anti-inflammatory activity of CKC-containing cationic emulsion eye drop vehicles

PURPOSE

Preservative-free cationic emulsion-based artificial tears (ATs) or drug vehicles are innovative eye drop formulations with tear film stabilization and drug delivery properties, and valuable in vivo anti-inflammatory and wound healing properties. These ATs have recently reached the market as ATs for the management of dry eye disease (DED) symptoms (i.e., Cationorm) or as a drug vehicle for cyclosporine (Ikervis). The aim of the present study was to explore the mechanism of action underlying the intrinsic anti-inflammatory and wound-healing efficacies harbored by the cationic emulsions of cetalkonium chloride (CE-CKC).

METHODS

The anti-inflammatory activity of two CE-CKC (0.002% and 0.005% CKC) emulsions was evaluated by assessing the expression of proinflammatory genes and the secretion of various markers in the following human cell types stressed by different agents: peripheral blood mononuclear cells (PBMCs; stimulation with anti-CD3/anti-CD28 or lipopolysaccharide (LPS)), CD4⁺ T lymphocytes (TCD4; stimulation with anti-CD3/anti-CD28), and a human corneal epithelial cell line (HCE-2; stimulation with LPS). The cells were incubated for 30 min with a 10% dilution of CE-CKC emulsions and then cultured without the emulsions for 24 h or 72 h in the presence of the various challenging agents. The supernatant was collected, and the secreted markers quantitated with flow cytometry or an enzyme-linked immunosorbent assay (ELISA). Gene expression of inflammatory markers was evaluated only in the PBMCs and HCE-2 cells stimulated with LPS. The in vitro protein kinase C (PKC) binding assay for IC₅₀ determination was performed using standard procedures.

RESULTS

The CE-CKC emulsions decreased inflammatory gene expression in LPS-stimulated PBMCs (IFN-γ, IL-17A, CXCL-9, and TNFα) and LPS-stimulated HCE-2 cells (THBS1 and CCL2). Both CE-CKC emulsions inhibited the secretion of IL-17 (from anti-CD3/anti-CD28-stimulated TCD4), TNFα, IFN-γ, and IL-2 (from anti-CD3-/anti-CD28-stimulated PBMCs), and IL-6 and IL-8 (from LPS-stimulated HCE-2). The in vitro PKC binding assay revealed that CKC, the cationic agent, is a specific PKCα inhibitor. In addition, tyloxapol, another excipient, showed some anti-inflammatory activity on IL-6 and IL-8 in the LPS-stimulated HCE-2 cells.

CONCLUSIONS

This study indicates that the CE-CKC emulsions are able to directly modulate the secretion and expression of proinflammatory cytokines and chemokines. The results also suggest that CKC and tyloxapol are pharmacologically active excipients with potentially beneficial effects in vivo. These data shed new light on the efficacy observed on the DED signs of these CE-CKC emulsions in clinical trials.

Efficacy of intra-meibomian gland injection of the anti-VEGF agent bevacizumab for the treatment of meibomian gland dysfunction with lid-margin vascularity

Purpose

To investigate the efficacy of a novel treatment - intra-meibomian gland (MG) injection of the anti-VEGF agent bevacizumab - for MG dysfunction (MGD) with eyelid-margin vascularity.

Methods

A total of 26 eyes from 13 patients diagnosed with MGD and eyelid-margin vascularity were included in our study. Patients received intra-meibomian gland injections of bevacizumab (150 μL, 2.5 mg/0.1 mL) at multiple sites with a 29 G needle where telangiectasia was severe. The Ocular Surface Disease Index (OSDI), tear film, tear-breakup time (TBUT), eyelid-margin features, MG features, conjunctiva, and corneal staining were assessed at 1 day before injection and 1 week, 1 month, and 3 months after injection. Blood pressure, best-corrected visual acuity, intraocular pressure, and slit lamp examinations were performed to assure the safety of patients at 1 day before and 1 day, 1 week, 1 month, and 3 months after injection.

Results

Lid-margin vascularity, conjunctival injection, expressed secretion quality, expressivity of the MG, TBUT, corneal staining, and OSDI were significantly improved 1 week, 1 month, and 3 months after injection compared to baseline values. Lid-margin vascularity, conjunctival injection, meibomian gland expressivity, TBUT, and OSDI continued to improve; the greatest improvements were observed at 1 month and sustained for 3 months. Spearman's correlation analysis indicated that age and sex significantly influenced TBUT improvement. Females and older patients tended to have shorter baseline TBUT that followed a different trend from that of males and younger patients during postinjection visits, revealed by subgroup analysis. No local or systemic side effects were observed at follow-up visits.

Conclusion

This study is the first to explore a novel therapy for MGD - intra-MG injection of the anti-VEGF agent bevacizumab - and it demonstrates that the treatment is effective and safe in eliminating eyelid-margin vascularity, improving MG function and relieving clinical signs and symptoms of MGD.

n-3 Fatty Acid Supplementation for the Treatment of Dry Eye Disease

BACKGROUND

Dry eye disease is a common chronic condition that is characterized by ocular discomfort and visual disturbances that decrease quality of life. Many clinicians recommend the use of supplements of n-3 fatty acids (often called omega-3 fatty acids) to relieve symptoms.

METHODS

In a multicenter, double-blind clinical trial, we randomly assigned patients with moderate-to-severe dry eye disease to receive a daily oral dose of 3000 mg of fish-derived n-3 eicosapentaenoic and docosahexaenoic acids (active supplement group) or an olive oil placebo (placebo group). The primary outcome was the mean change from baseline in the score on the Ocular Surface Disease Index (OSDI; scores range from 0 to 100, with higher scores indicating greater symptom severity), which was based on the mean of scores obtained at 6 and 12 months. Secondary outcomes included mean changes per eye in the conjunctival staining score (ranging from 0 to 6) and the corneal staining score (ranging from 0 to 15), with higher scores indicating more severe damage to the ocular surface, as well as mean changes in the tear break-up time (seconds between a blink and gaps in the tear film) and the result on Schirmer's test (length of wetting of paper strips placed on the lower eyelid), with lower values indicating more severe signs.

RESULTS

A total of 349 patients were assigned to the active supplement group and 186 to the placebo group; the primary analysis included 329 and 170 patients, respectively. The mean change in the OSDI score was not significantly different between the active supplement group and the placebo group (-13.9 points and -12.5 points, respectively; mean difference in change after imputation of missing data, -1.9 points; 95% confidence interval [CI], -5.0 to 1.1; P=0.21). This result was consistent across prespecified subgroups. There were no significant differences between the active supplement group and the placebo group in mean changes from baseline in the conjunctival staining score (mean difference in change, 0.0 points; 95% CI, -0.2 to 0.1), corneal staining score (0.1 point; 95% CI, -0.2 to 0.4), tear break-up time (0.2 seconds; 95% CI, -0.1 to 0.5), and result on Schirmer's test (0.0 mm; 95% CI, -0.8 to 0.9). At 12 months, the rate of adherence to treatment in the active supplement group was 85.2%, according to the level of n-3 fatty acids in red cells. Rates of adverse events were similar in the two trial groups.

CONCLUSIONS

Among patients with dry eye disease, those who were randomly assigned to receive supplements containing 3000 mg of n-3 fatty acids for 12 months did not have significantly better outcomes than those who were assigned to receive placebo. (Funded by the National Eye Institute, National Institutes of Health; DREAM ClinicalTrials.gov number, NCT02128763 .).

Treatment outcomes in the DRy Eye Amniotic Membrane (DREAM) study

Purpose

To evaluate the efficacy of cryopreserved amniotic membrane (CAM) in reducing signs and symptoms of dry eye disease (DED) in a large patient population.

Methods

A retrospective chart review at 10 clinical sites was done of patients with refractory DED who received CAM and completed at least 3 months of follow-up. Data collected were demographics; medical history including previous and current ocular treatment, diagnosis, clinical presentations, comorbidity, duration and frequency of treatment with CAM; and concomitant medications. The primary outcome was the change in dry eye workshop (DEWS) score after treatment.

Results

A total of 97 eyes of 84 patients exhibited severe dry eye despite maximal medical treatments including topical artificial tears, cyclosporine-A, serum, antibiotics, and steroids. Patients manifested with superficial punctate keratitis (86%), filamentary keratitis (13%), exposure keratitis (19%), neurotrophic keratitis (2%), and corneal epithelial defect (7%). After CAM treatment for 5.4±2.8 days, 74 (88%) patients demonstrated an improved ocular surface along with a notable reduction of the severity as the overall DEWS score was significantly reduced from 3.25±0.5 at baseline to 1.44±0.6 at 1 week, 1.45±0.6 at 1 month, and 1.47±0.6 at 3 months (p<0.001). Ten eyes (10%) required repeated treatment to complete healing. Apart from discomfort during CAM placement, there were no adverse events.

Conclusion

Placement of CAM is promising to enhance the recovery of ocular surface health and reduce signs and symptoms in patients with moderate-to-severe DED.

Patient and physician perspectives on the use of cyclosporine ophthalmic emulsion 0.05% for the management of chronic dry eye

Dry eye disease (DED) is a multifactorial disease of the ocular surface and is one of the most common reasons for patients to visit an eye care provider. Cyclosporine A (CsA) is an immune modulating drug that was approved in the US for topical use in the treatment of DED in 2003, which led to a paradigm change in our understanding and treatment of DED, turning attention to control of inflammation for treatment. This review summarizes the literature to date regarding the impact of CsA on the treatment of DED. A special focus is given to the patient and physician perspectives of CsA, including dry eye symptom improvement, medication side effects, and overall patient satisfaction. Studies evaluating CsA in DED have considerable heterogeneity making generalized conclusions about the effect of CsA difficult. However, most studies have demonstrated improvement in at least some symptoms of dry eye in CsA-treated patients. Side effects, most commonly ocular burning on administration of CsA, are common. The literature is sparse regarding long-term follow-up of patients treated with CsA, optimal duration of treatment, and identifying which patients may receive the most benefit from CsA.

Clinical impact of inflammation in dry eye disease: proceedings of the ODISSEY group meeting

Dry eye disease (DED) is a common, multifactorial ocular condition with major impact on vision and quality of life. It is now well recognized that the pathophysiology of chronic DED can include a cycle of inflammation involving both innate and adaptive immune responses. Recently, in vitro/in vivo models have been used to obtain a better understanding of DED‐related inflammatory processes at molecular/cellular levels although they do not truly reproduce the complex and chronic hallmarks of human DED. In clinical DED research, advanced techniques such as impression cytology, conjunctival biopsy, in vivo confocal microscopy and multiplex tear analyses have allowed an improved assessment of inflammation in DED patients. This was supported by the identification of reliable inflammatory markers including matrix metalloproteinase‐9, human leucocyte antigen‐DR or intercellular adhesion molecule‐1 in tears and impression cytology samples. One of the current therapeutic strategies focuses on breaking the inflammatory cycle perpetuating the ocular surface disease, and preclinical/clinical research has led to the development of promising anti‐inflammatory compounds. For instance, cyclosporine, already approved in the United States, has recently been authorized in Europe to treat DED associated with severe keratitis. In addition, other agents such as corticosteroids, doxycycline and essential fatty acids, through their anti‐inflammatory properties, show encouraging results. We now have a clearer understanding of the inflammatory processes involved in DED, and there is hope that the still emerging preclinical/clinical findings will be translated into new and highly effective therapies for patients in the near future.

Modern Therapeutic Approaches for Noninfectious Ocular Diseases Involving Inflammation

Dry eye disease, age-related macular degeneration, and uveitis are ocular diseases that significantly affect the quality of life of millions of people each year. In these diseases, the action of chemokines, proinflammatory cytokines, and immune cells drives a local inflammatory response that results in ocular tissue damage. Multiple therapeutic strategies are developed to either address the symptoms or abate the underlying cause of these diseases. Herein, the challenges to deliver drugs to the relevant location in the eye for each of these diseases are reviewed along with current and innovative therapeutic approaches that attempt to restore homeostasis within the ocular microenvironment.