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To assess the relationship between tear inflammatory cytokine ratios (CRs) and signs and symptoms of dry eye disease (DED) to investigate the possible use of tear CRs, which may better address the complexity of cytokine interactions than absolute cytokine levels, as a DED biomarker. Tear concentrations of IL-1b, IL-6, IL-8, IL-10, IL-17A, IFN-g, and TNF-a were measured using standardized procedures, as were DED signs (corneal and conjunctival staining scores, tear break-up time, Schirmer test, Meibomian gland plugging, tear osmolarity, composite sign severity score) and symptoms [Ocular Surface Disease Index (OSDI)]. Ratios between pro-inflammatory (IL-1b, IL-8, IL-17A, IFN-g, and TNF-a) and anti-inflammatory (IL-10) cytokines were calculated. Given its opposing roles in inflammation, IL-6 was tested as both a pro- and anti-inflammatory cytokine. Correlations between CR and DED symptoms and signs were calculated using Spearman correlation coefficients (rho). At baseline, 131 patients, 80.2% female and mean age 54.2 years (SD 14.1, range 20–82), from 10 sites of the Dry Eye Assessment and Management study had sufficient tear volumes ≥4 μL for analysis. IL-6:IL-10, IL-8:IL-10, and TNF-a:IL-10 had some significant correlations, mostly with conjunctival or corneal staining or the composite sign severity score (IL-8:IL-10 and conjunctival staining: rho = 0.19, p = 0.03; IL-6:IL-10 and corneal staining: rho = 0.31, p < 0.001; IL-8:IL-10 and corneal staining: rho = 0.21, p = 0.01; IL-6:IL-10 and composite sign severity score: rho = 0.26, p = 0.003; IL-8:IL-10 and composite sign severity score: rho = 0.26, p = 0.003; TNF-a:IL-10 and corneal staining: rho = 0.29, p < 0.001; TNF-a:IL-10 and Schirmer test: rho = −0.23, p = 0.009). CRs had no significant correlation with DED symptoms. All significant correlations using IL-6 in the denominator (anti-inflammatory) produced counterintuitive results based on clinical understanding of the disease. Pro- to anti-inflammatory CR was weakly correlated with some DED signs and not with symptoms, as measured by OSDI. Future studies in different dry eye populations are needed and should address sampling biases and tear collection techniques. [ABSTRACT FROM AUTHOR]

The Ocular Surface Disease Index (OSDI) is the most frequently used dry eye disease (DED) questionnaire, and the Symptom Assessment iN Dry Eye (SANDE) is the simplest and quickest to apply. We analyze the correlation and level of agreement between these two questionnaires in a large DED heterogeneous population to evaluate their performance and potential interchangeability. Prospective, multicenter longitudinal survey-based study performed on patients diagnosed with DED by 99 ophthalmologists from 20/32 Mexican states. Questionnaires were applied in two consecutive visits to analyze the correlation between OSDI and SANDE to evaluate patients with DED clinically. Level of agreement was evaluated with Bland-Altman analysis, and internal consistency of instruments was evaluated individually and combined with Cronbach's alpha index. 3421 patients studied: 1996 (58.3%) women and 1425 (41.7%) men, aged 49.5 ± 15.4 years; 995 (29.1%) patients had aqueous-deficient, 1086 (31.7%) evaporative, and 1340 (39.2%) mixed DED subtypes. Normalized baseline scores were 53.7 (OSDI) and 54.1 (SANDE). After 36.3 ± 24.4 days between visits, scores were reduced to 25.2 (OSDI) and 21.8 (SANDE) points (p <.001). A positive correlation between questionnaires was found at baseline (R = 0.592; p <.001), follow-up (R = 0.543; p <.001) and change between visits (R = 0.630; p <.001). Using both questionnaires together improved the overall reliability of symptom evaluation at baseline (α = 0.7), follow-up (α = 0.7), and both (α = 0.7), compared to individual application (OSDI α = 0.5, SANDE α = 0.6)—the same improvements applied to all DED subtypes. Bland-Altman analysis revealed a differential bias of -0.41% at baseline and +3.6% at follow-up visits between OSDI and SANDE. We validated the correlation (high precision) between questionnaires in a large-scale population, demonstrating improved reliability (high accuracy) in evaluating DED when used together, challenging their interchangeable use. These results open a venue to improve recommendations toward a more precise and accurate diagnostic and therapeutic evaluation of DED by using OSDI and SANDE concurrently. [ABSTRACT FROM AUTHOR]

To evaluate the effect of air pollution on the tear film stability by analyzing the correlation between Air Quality Index (AQI) and Lipid Layer thickness (LLT) in Xuzhou. As a prospective descriptive observational study, 284 patients with meibomian gland dysfunction (MGD), 157 patients with Sjögren's syndrome (SS), and 264 healthy volunteers were included. The tear film lipid layer thickness of the three groups of subjects was measured weekly and compared with the air quality index to analyze the correlation between the two indicators. Logistic regression analysis and linear regression analysis were used to analyze the effect of AQI on the thickness of the tear film lipid layer. The change of LLT with air pollution at different AQI levels was also analyzed. There are obvious seasonal differences in the changes of air pollution index in Xuzhou. Significant differences could be observed in the thickness of the lipid layer of the tear film among the three groups. LLT in the MGD group and SS group decreased with the aggravation of air pollution, while remained unchanged in the control group. There was strong evidence of correlation between LLT of the MGD group (F = 353.494, p < 0.01, adjusted R2 = 0.695) and the SS group (F = 502.404, p < 0.01, adjusted R2 = 0.764) with AQI, while there was minor correlation between LLT with AQI in control group (F = 8.525, p < 0.01, adjusted R2 = 0.046). Air pollution can cause a decrease in the thickness of the tear film lipid layer, thereby affecting tear film stability, leading to the occurrence of dry eye. [ABSTRACT FROM AUTHOR]

To describe tear concentrations of IL-1β, Il-6, IL-8, IL-10, IL-17A, IFNγ and TNFα in tears, collected by microcapillaries, and their correlation with symptoms and signs in subjects with dry eye disease (DED) in the DREAM Study. Cytokine levels of patients with moderate to severe DED were determined using a magnetic bead assay. Scores for Ocular Surface Disease Index, corneal and conjunctival staining, tear break-up time (TBUT), and Schirmer's test were obtained using standardized procedures. Associations of cytokines with each other and signs/symptoms were assessed with Spearman correlation coefficients (r). Assay results from 131 patient samples from 10 sites with tear volumes ≥ 4 ul were analyzed. Cytokine concentrations did not correlate with each other in a generally acknowledged pro-inflammatory/anti-inflammatory pattern, such as proinflammatory IL-17A and IFNγ were not inversely correlated to anti-inflammatory cytokine IL-10, and cytokines did not correlate with DED symptoms. Lower corneal staining was correlated with higher concentrations of IL-17A (r= −0.24, p = 0.006), IL-10 (r= −0.25, p = 0.005) and IFNγ (r= −0.33, p = 0.0001). Higher concentrations of IFNγ were associated with lower conjunctival staining (r= −0.18, p = 0.03). Higher concentrations of IL-17A were associated with higher TBUT scores (r = 0.19 p = 0.02). Cytokines IL-10, IL-17A and IFNγ were highly correlated with each other but weakly correlated with some DED signs. No key cytokines or definitive expression patterns were identified in this study of moderate to severe DED patients. Further studies addressing various biases, including methodological and sampling biases, and standardization of methodology for inter-laboratory consistency are needed to confirm and establish pathological and clinical relevance of tear cytokines in DED. [ABSTRACT FROM AUTHOR]

To determine the metabolic activity, and cytokine expression over time from immortalized human corneal epithelial cells (HCECs) exposed to hyperosmotic stress. HCECs were cultured and expanded in DMEM/F-12 with 10% FBS. The cells were exposed to either normal media (295 mmol/kg) or hyperosmolar media (500 mmol/kg) for 0.25, 3, 6, and 12 hours. After each exposure duration, metabolic activity was quantified using alamarBlue, and a panel of pro-inflammatory cytokines (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, TNF-α, IFN-γ, and IL-17A) was quantified using multiplexed electrochemiluminescence (Meso Scale Diagnostics, Rockville, MD). Metabolic activity of the HCEC exposed to hyperosmolar conditions was significantly reduced at the 3-, 6-, and 12-hour mark compared to the control (all p < 0.01). There was no significant difference in cytokine expression between the hyperosmolar media and control at the 0.25- and 3-hour mark for all cytokines (all p ≥ 0.28). The difference in cytokine expression between the hyperosmolar media and the control was significant for IL-1β, IL-4, IL-6, IL-8, IL-12p70, IL-13, and TNF-α at the 6-hour mark (all p ≤ 0.02). No significant change in cytokine expression between the hyperosmolar media and control was noted for IL-2, IL-10, IL-17A, and IFN-γ (all p ≥ 0.74) at the 6-hour mark. Hyperosmolar stress reduced cell metabolic activity and increased expression of IL-1β, IL-4, IL6, IL8, IL-12p70, IL-13, and TNF-α over a 6-hour period in an immortalized HCEC line. [ABSTRACT FROM AUTHOR]

To evaluate the short- (within 90 min) and long-term (after 21 days of treatment) effects of an artificial tear containing carbomer, hyaluronic acid, glycerol, and medium-chain triglycerides in patients with mild-to-moderate dry eye symptoms. Subjects received the tested artificial tears in the right eye and control artificial tears in the left eye and were assessed 10, 30, 60, and 90 min after instillation in the short-term study phase. They received the study product in both eyes in the long-term phase. Non-invasive break-up time (NIBUT), tear lipid layer pattern, tear evaporation, and tear film objective optical dynamics (TFOOD) were measured in controlled environmental conditions. In total, 32 patients (10 males, mean age 42 ± 11 years) were enrolled. During the short-term phase, NIBUT increased significantly in the right eyes at all time points compared with baseline (all p < 0.05). Conversely, in the left eyes, NIBUT increased significantly at 10 and 30 min (p < 0.05). The tear evaporation values increased at 10 min and decreased at 30 and 60 min (p < 0.05) in the right eyes, while they increased only at 10 min (p < 0.05) in the left eyes. Compared with baseline, the TFOOD was significantly more stable at all time points in the right eyes (p < 0.05), while it was more stable at 10 and 30 min in the left eyes (p < 0.05). In the long-term phase, treated eyes showed a significant increase in NIBUT values, a significant reduction of tear evaporation, a significant improvement of tear lipid layer pattern, and a more stable TFOOD compared with baseline (all p < 0.05). Symptoms, measured with the Ocular Surface Disease Index questionnaire, were also significantly reduced compared with baseline (p < 0.05). The tested product increased tear film stability and reduced tear evaporation, normalizing lipid layer pattern and reducing symptoms in the short- and long-term observation. [ABSTRACT FROM AUTHOR]

Dry eye disease (DED) is a common disorder that remains challenging from a clinical perspective. Unstable or deficient tear film is a major factor contributing to DED and the inability to resolve the loss of tear film homeostasis that accompanies DED can result in a vicious circle of inflammation and treatment-refractory disease. Recently recognized as a multifactorial disease, the main etiological subtypes of DED are aqueous-deficient and evaporative which exist on a continuum, although evaporative dry eye (EDE) is the more frequent classification. Although attaining greater recognition in recent years, there is currently no consensus and no clear recommendation on how to manage EDE. Clarity on the early diagnosis and treatment of EDE may facilitate the avoidance of progression to chronic inflammation, permanent damage to the ocular surface, and treatment-refractory disease. The purpose of this review was to identify current best practice for management of EDE in order to help clinicians in providing accurate diagnosis and optimized treatment. We summarize recent literature considering the role of the lipid layer on tear film stability, the importance of its composition and of its dynamic behavior, and the link between its malfunction and the insurgence and maintenance of tear film-related diseases. We have provided an assessment of the best management of lipid-deficient EDE based upon an understanding of disease pathophysiology, while indicating the flow of current treatments and possible future evolution of treatment approaches. Lipid containing eye drops may be considered as a step closer to natural tears from artificial aqueous tears because they more closely mimic the aqueous and lipid layers and may be used in combination with other management approaches. As a next step, we recommend working with a wider expert group to develop full guidelines to enable patient-centered management of EDE. Dry eye is a multifactorial disease of variable presentation with the tendency to become a chronic disease for which it is essential to identify and treat the main pathogenic mechanisms involved and tailor the treatment to the individual patient. Early intervention is needed to prevent the vicious cycle of DED and may require a multi-faceted management approach. EDE is not just a problem of MGD but can be the result of anything affecting blinking, mucin spreading, aqueous layer volume and content. Lipid-containing eye drops may provide significant relief of symptoms by improving the lipid layer and its spreading ability and, as such, are an appropriate component of the overall management of lipid-deficient EDE; natural lipid-containing eye drops should be the preferred treatment. [ABSTRACT FROM AUTHOR]

To investigate the role and mechanism of melatonin-loaded polymer polyvinyl caprolactam–polyvinyl acetate–polyethyleneglycol graft copolymer micelles (Mel-Mic) in dry eye disease (DED). In vitro, the apoptosis and reactive oxygen species (ROS) generation in human corneal epithelial cells (HCECs) were analyzed by immunostaining and flow cytometry. The effect of Mel-Mic on autophagy and mitophagy was evaluated by immunostaining and western blots. PINK1 knockdown was analyzed by small interfering RNA. In vivo, sodium fluorescein staining, tear secretion test, and periodic acid-Schiff staining were used to determine whether Mel-Mic can alleviate the severity of DED. Small molecule antagonists were pretreated to investigate whether melatonin type 1 and/or 2 receptors (MT1/MT2) mediate the effects of Mel-Mic. Mel-Mic improved the solubility and biological activities of Mel in aqueous solutions. Treatment with Mel-Mic decreased the apoptosis of HCECs exposed to hyperosmotic medium, accompanied by downregulation of cleaved Caspase-3 and upregulation of Bcl-2. In addition, Mel-Mic application suppressed ROS overproduction, rescued mitochondrial function, and decreased the level of oxidative stress associated biomarkers (COX-2 and 4-HNE) in HCECs. Interestingly, HCECs treated with Mel-Mic exhibited increased levels of mitophagy markers (PINK1, PARKIN, Beclin 1, and LC3B) and restored impaired mitophagic flux under hyperosmolarity. While PINK1 knockdown largely abolished its protective effects. In vivo, compared to vehicle group, topical Mel-Mic-solution-treated mice showed significantly improved clinical parameters, increased tear production, and decreased goblet cells loss in a dose-dependent manner. Also, transmission electron microscopic assay revealed increased autophagosome number in the corneal epithelium of Mel-Mic group. Moreover, luzindole, a nonselective MT1/MT2 antagonist, but not 4-P-PDOT, a selective MT2 antagonist, blocked the protective effect of Mel-Mic. Our findings demonstrated that Mel-Mic ameliorates hyperosmolarity-induced ocular surface damage via PINK1-mediated mitophagy and may represent an effective treatment for DED possibly through acting MT1 receptor. [ABSTRACT FROM AUTHOR]

Growing evidence emphasizes the role of inflammation and oxidative stress in the pathogenesis of Dry Eye Syndrome (DES). Concordantly, the importance of agents targeting the inflammatory cascade and oxidative stress in the treatment is also progressively increasing. Herein, the study has investigated the protective effects and underlying mechanism of allyl isothiocyanate (AITC) on the ocular surface in a benzalkonium chloride (BAC)-induced dry eye rat model. A total of twenty-one Wistar albino rats were used to form the following three groups: Control, BAC, BAC + AITC. DES was established by topical application of BAC (four times daily for two weeks) in two groups, of which one group was treated with AITC (10 mg/kg BW daily oral dosage) for four weeks. Rats were monitored by dry eye diagnostic tests during the study period, and eventually, corneal tissues were used to evaluate for histopathologic analyzes and inflammatory and oxidative status. A significant improvement was observed in various histopathologic and ophthalmologic findings, including tear volume, tear film integrity, ocular surface damage, ocular inflammatory signs, corneal thickness, and edema through AITC supplementation. AITC prominently balanced the inflammatory status and oxidative stress by lowering key proinflammatory mediators (NF-κB, TNF-α, IL-1β, IL-6, and IL-8) and increasing the activities of antioxidant enzymes (SOD, GSH-Px). Also, levels of protective tear proteins, including Muc1, Muc4, and Muc5 were recovered with AITC supplementation. AITC alleviates clinical and histopathologic signs related to DES. Antioxidative and anti-inflammatory properties of AITC play a significant role in the mechanism of action. [ABSTRACT FROM AUTHOR]

Dry eye disease (DED), a multifactorial condition of the tear film and ocular surface, is one of the leading reasons for patients seeking eye care. Despite the multiple toxic ingredients of eye make-up products and their long-term application close to the ocular surface, few studies have analyzed their role in initiating and worsening DED. Females and the elderly experience the highest prevalence of DED and may be particularly vulnerable to the effects of eye make-up. The multifactorial nature of DED and common mechanisms behind several ocular surface diseases make it difficult to link a particular ingredient-driven mechanism to DED. Therefore, here, we list potential responses to eye cosmetics that may be involved in DED development. The first part of this review introduces the anatomy of the eye and DED, the second section explains the classification of eye cosmetic products, and the final part discusses the undesired effects under physical, pathogenic, and chemical insults. [ABSTRACT FROM AUTHOR]

Dry eye (DE) disease is a multifactorial disease in which uncontrolled inflammation can lead to corneal epithelium lesions and symptoms of discomfort. The aim of the present study was to evaluate the efficacy of two cyclosporine emulsions in a mouse model of DE with corneal epithelium lesions. Six- to 9-week-old female C57BL/6 N mice were housed in a controlled-environment room to induce DE. Following DE development, mice were instilled with: QD 0.1%CsA cationic emulsion (CaEm), BID 0.05%CsA anionic emulsion (AEm), or left untreated. Aqueous tear production and corneal epithelium lesions were assessed throughout the experiment. At the end of the treatment period, left eyes were sampled, fixed, and stained for histology, while the cornea, conjunctiva, and lacrimal gland of right eyes were sampled for transcriptomic analysis. Corneal lesion scores were reduced by 10.4%, 18.4%, and 10.9% at day 6, 10, and 14, respectively, with CaEm (QD), and by 2.6%, 3.0%, and 5.5% at day 6, 10, and 14, respectively, with AEm (BID). Histology demonstrated that 7 out of 10 DE mice presented moderate to severe ocular lesions, while only 2 and 5 out of 10 mice presented slight to moderate ocular lesions when treated with the CaEm (QD) and AEm (BID), respectively. The transcriptomic profile analysis suggests that a different set of inflammatory genes are modulated in the cornea, conjunctiva, and lacrimal gland upon DE development. In addition, the two emulsions distinctively modulate the gene expression profile. This study demonstrates that both emulsions were effective at reducing corneal lesions, with the CaEm (QD) being slightly better than the AEm (BID). Interestingly, this study suggests that ocular tissues may not respond similarly to a dry environment and that a different set of genes is modulated by the two formulations in the ocular tissues. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the efficacy of a preservative free sodium hyaluronate/chondroitin sulfate ophthalmic solution (SH/CS-PF) in patients with dry eye disease (DED). Methods: This was a randomized phase IV, multicentric, prospective, double-blind clinical trial. Intent-to-treat (ITT) and per-protocol (PP) analyses were performed. Patients were assigned to receive either SH/CS-PF, Systane® Ultra (PEG/PG) or Systane® Ultra PF (PEG/PG-PF) for 90 days. A total of 326 patients were included in the ITT, and 217 in the PP analysis. Efficacy endpoints were goblet cell density, Nelson's grades (conjunctival impression cytology), tear break-up time (TBUT), Ocular Surface Disease Index (OSDI), and Schirmer's test. Other parameters included were tolerability, measured by the ocular symptomatology; and safety, measured through corneal staining, intraocular pressure, visual acuity and adverse events. Results: In the ITT, there was a significant increase in mean goblet cell density in all treatments compared with their baseline (28.4% vs 21.4% and 30.8%), without difference between arms (p =.159). Eyes exposed to SH/CS-PF, PEG/PG and PEG/PG-PF showed Grade 0-I squamous metaplasia (85.5%, 87.9% and 93.2%, respectively). Similar improvements were observed for TBUT (1.24 ± 2.3s vs 1.27 ± 2.4s and 1.39 ± 2.3s) and OSDI scores at day 90 (−8.81 ± 8.6 vs −7.95 ± 9.2 and −8.78 ± 9.8), although no significant intergroup difference was found. Schirmer's test also presented improvement compared to baseline (1.38 ± 4.9 vs 1.50 ± 4.7 and 2.63 ± 5.9), with a significantly higher variation for PEG/PG-PF. There were no significant differences between treatments for any tolerability and safety parameter, nor between ITT and PP analyses for any outcome. Conclusions: The topical application of SH/CS-PF is as effective, safe and well tolerated as that of PEG/PG or PEG/PG-PF. The results suggest that SH/CS-PF may lead to normalization of clinical parameters and symptom alleviation in patients treated for DED. [ABSTRACT FROM AUTHOR]

Dry eye disease (DED) is a multifactorial disease of the ocular surface characterized by loss of homeostasis of the tear film and accompanied by symptoms such as ocular discomfort and visual disturbance. DED is one of the most common reasons for seeking medical care in the United States and across the world. Despite this, there are a limited number of pharmacologic therapies for the treatment of DED in the United States and Europe. This review examines the different pivotal trials for DED medications and the impact the vehicle in each trial. In recent clinical trials, the vehicle of the active formulation of the medication is often used as the active comparator. A literature review of published dry eye clinical trials was performed to identify the pivotal clinical trials of DED medications and to compare treatment effect and further understand the impact of the vehicle on clinical trial outcomes. The pivotal clinical trials for the currently approved treatments for dry eye have widely varying study designs. The variations include differences in inclusion criteria, outcome measures and efficacy endpoints, and whether or not the use of concomitant artificial tears is allowed. These differences make it difficult for accurate comparisons to be made between DED medications. Each trial demonstrated that the vehicle alone has some beneficial effect on signs and symptoms of dry eye disease. This review discusses the varying trial designs and vehicles used in the pivotal studies for the four approved dry eye medications in the United States and Europe, as well as novel vehicles under development and clinical trial recommendations. [ABSTRACT FROM AUTHOR]

Dry eye disease (DED) is a multifactorial disease of the ocular surface characterized by loss of homeostasis of the tear film. Epidemiological studies suggest it occurs more frequently in women than men. The aim of this retrospective analysis was to determine whether patients with DED show gender-specific differences in symptoms and signs. A retrospective analysis of 107 patients was conducted at the Department of Ophthalmology of the University of Düsseldorf – Germany. After completing the OSDI questionnaire, the patients underwent objective refraction and were asked about the following symptoms: burning, itching, foreign body sensation, epiphora, sticky eyes, pain, red eyes and swollen eyelids. Furthermore, they underwent an evaluation of the following signs: lipid layer thickness, non-invasive break-up-time (NI-BUT), conjunctival hyperemia, lid parallel conjunctival folds, meibography, Schirmer test and tear meniscus height, ocular surface staining, expressibility of meibomian glands. Of the 107 patients (56.2 ± 17.3 years) 75 were women and 32 men. Women reported significantly more often eyelid swelling (p =.03) and showed a tendency to complain more about red eyes (p =.051), while men tended to complain more often about epiphora (p =.053). In an age-matched sample taken from the cohort, significant differences were found for OSDI-scores (p =.025) showing women reporting more symptoms compared to men, while men showed more conjunctival hyperaemia (p =.004) than women. Women showed a significant thicker lipid layer (p =.0009) in the full cohort, but not in the age-matched sample (p =.43). Although the majority of the investigated parameters did not show gender-specific differences, women reported higher OSDI scores. These findings could be explained by an increased frequency of neuropathic symptoms or ocular surface sensitivity in women or higher resilience of men to consult an ophthalmologist. Sex may have an effect on the clinical characteristics of DED, but further studies are needed to confirm these findings. [ABSTRACT FROM AUTHOR]

The lacrimal glands produce the aqueous component of the pre-ocular tear film, which is essential for ocular health and optimal vision. This review explores its history, current understanding, and recent advances, and scope for future research. It traces the evolution of human knowledge about the source of tears across several millennia, with specific emphasis on the individuals who made seminal contributions to this field. It provides a detailed update on the morphology, microscopic structure, innervation, vascular supply, and imaging modalities of both the main and accessory lacrimal glands. The review also summarizes the recent advances in lacrimal gland regeneration and repair for the treatment of dry eye disease, particularly the role of mesenchymal stem cells. Lastly, the review gazes into the future of lacrimal gland research, which aims at translating the existing laboratory knowledge into clinical application, with the possibility of transplanting in vitro cultivated lacrimal constructs or the use of cell-based therapies for in situ repair of diseased human lacrimal glands. The lacrimal glands produce the aqueous component of the pre-ocular tear film, which is essential for ocular health and optimal vision. This review explores its history, current understanding, recent advances, and scope for future research. The authors reviewed the major studies discussing the history of lacrimal glands and their anatomical description, including microscopic anatomy, innervation patterns, imaging, and ongoing translational research. The review traces the evolution of human knowledge about the source of tears across several millennia, with specific emphasis on the individuals who made seminal contributions to this field. It provides a detailed update on the morphology, microscopic structure, innervation, vascular supply, and imaging modalities of both the main and accessory lacrimal glands. The review also summarizes the recent advances in lacrimal gland regeneration and repair for the treatment of dry eye disease, particularly the role of mesenchymal stem cells. Lastly, the review gazes into the future of lacrimal gland research, which aims at translating the existing laboratory knowledge into clinical application, with the possibility of transplanting in vitro cultivated lacrimal constructs or the use of cell-based therapies for in situ repair of diseased human lacrimal glands. Knowledge about the lacrimal glands in health and disease has improved tremendously since its discovery in the mid-eighteenth century. Today we stand at the cusp of exploring potential regenerative approaches for the treatment of lacrimal gland damage in dry eye disease. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of age, gender and body mass index (BMI) on the levels of tear film neuromediators and corneal nerve parameters in healthy individuals. Methods: Twenty-six healthy subjects were screened for any neurological deficits. The concentration of substance P and calcitonin gene-related peptide (CGRP) in tears was measured by enzyme-linked immunosorbent assay. Corneal nerve fibers were imaged using confocal microscopy and assessed by automated image analysis software. Associations between the clinical variables were analyzed using Pearson or Spearman correlation. Univariate general linear regression was performed to examine the independent relationship between age, BMI and gender of the subjects with concentrations of substance P, CGRP and corneal nerve fiber parameters. Results: Fifteen (58%) of the study participants were male. The mean age of the study cohort was 36 ± 12 years (range, 21–59) with an average BMI of 25 ± 4 kg/m2. The median [IQR] concentrations of substance P and CGRP was 715 [372–1463] pg/mL and 38 [15–74] ng/mL respectively. Moderate but significant positive correlations were found between the concentration of substance P and corneal nerve fiber density (r = 0.467, P =.016), nerve fiber length (r = 0.528, P =.006) and nerve fractal dimension (rs = 0.614, P =.002). There was a significant age-dependent reduction in the concentration of substance P (−6% pg/mL per year, P =.001) and CGRP (−8% ng/ml per year, P <.001). Corneal nerve fiber density (−0.171 no./mm2 per year, P =.029) and nerve fractal dimension (−0.001 per year, P =.021) showed reductions with advancing age. Gender and BMI did not influence any of the measurements. Conclusions: The concentrations of substance P and CGRP in tears, as well as corneal nerve fiber density and nerve fractal dimension, are significantly reduced with advancing age. Age should be considered when evaluating patients for diagnosis and follow-up of corneal neuropathy or ocular surface disorders. [ABSTRACT FROM AUTHOR]

Aim: To discuss the immunological mechanism in electroacupuncture (EA) treatment of dry eye syndrome (DES) by targeting the changes in conjunctival cytokine expression profile. Method: Eligible DES patients were randomized into an EA group (EAG) or an acupuncture group (AG). The ocular surface disease index (OSDI), amount of tear production, and tear film break-up time (BUT) were observed to evaluate the efficacy. Conjunctival cells were collected from both effective and invalid cases to observe the expressions of cytokines by protein microarray. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used for functional cluster and signaling pathway analysis of the differentially expressed proteins. Enzyme-linked immunosorbent assay (ELISA) was used to verify the specific differential proteins. Result: After treatment, OSDI dropped and BUT extended in both groups, and the tear production increased only in the EAG (all P <.01). Compared with the AG, the improvement in tear production was more significant in the EAG (P <.01). There were 17 differentially expressed conjunctival cytokines between the effective and invalid cases in the EAG, and those expressed higher than the limit of detection (LOD) included monocyte chemoattractant protein 1 (MCP-1), macrophage colony-stimulating factor (M-CSF), regulated on activation in normal T-cell expressed and secreted (RANTES) and tissue inhibitor of metalloproteinases 1 (TIMP-1). GO analysis showed that the differential cytokines were mainly involved in cellular interaction, signaling pathways and reactions to stimuli. KEGG analysis revealed that the signaling pathways of these cytokines were mainly responsible for interactions between cytokines or between cytokines and their receptors, such as Jak-STAT signaling pathway, chemokine signaling pathway, and tumor necrosis factor signaling pathway. Conclusion: EA can effectively treat DES by improving the symptoms, increasing tear secretion and extending BUT, which is possibly related to its regulation on the conjunctival cytokine expressions. [ABSTRACT FROM AUTHOR]

Dry eye disease (DED) is a complex and multifactorial disease resulting in a continual cycle of tear hyperosmolarity and inflammation. Patients suffering from DED experience severe pain and visual impairments leading to a reduced quality of life. Aqueous-deficient dry eye (ADDE), mainly caused through a loss of functional lacrimal gland tissue, results in the most severe forms of DED. Despite a high prevalence, the current treatments remain palliative and may be insufficient to alleviate the symptoms. Consequently, investigations on experimental approaches for in situ lacrimal gland regeneration are of great clinical interest. This article reviews the current knowledge about processes involved in lacrimal gland regeneration, about lacrimal gland resident stem cells, and offers deductions about possible concepts for in situ lacrimal gland regeneration. Promising starting points might be the utilization of therapeutic proteins, such as bone morphogenetic protein 7, mesenchymal stem cells (MSC) or MSC-based treatments such as conditioned medium, lyophilized cell extracts or adult acinar cells. This review further summarizes current experimental approaches for the treatment of ADDE in animal models and patients. Approaches investigating side population stem cells, epithelial progenitor cells and MSC showed that the transplantation of these cells had therapeutic effects on ADDE. However, the most promising and best-studied experimental approach is the use of MSC for induction/enhancement of in situ lacrimal gland regeneration. Their immunomodulatory effects, low immunogenicity, promotion of tissue regeneration and involvement during spontaneous lacrimal regeneration are favorable traits for clinical applications. In addition, the efficacy and safety of allogeneic MSC transplantation have already been demonstrated in a small patient cohort. [ABSTRACT FROM AUTHOR]

Purpose: To compare the prevalence of dry eye disease between children with and without diabetes, and analyze the factors associated with dry eye disease in children with diabetes. Materials and methods: 38 children with diabetes were selected as cases, and 40 children without diabetes constituted the control group. The prevalence of dry eye disease in both groups was statistically analyzed. Related factors of dry eye disease were analyzed in children with diabetes. Results: The prevalence of dry eye disease in the case group was significantly higher than that in the control group (P <.01), with the attributable proportion among the exposed (0.827) and the population attributable fraction (0.700). Univariate analysis showed that the diabetes duration, best-corrected visual acuity, corneal sensation, and levels of glycosylated hemoglobin were associated with dry eye disease in children with diabetes. Logistic regression analysis revealed that only diabetes duration and corneal sensation were independent factors associated with dry eye disease. The diabetes duration was significantly higher and the level of corneal sensation was significantly lower in subjects with dry eye disease than in those without dry eye disease. Conclusions: Early screening and close follow-up of dry eye disease in children with diabetes should be strictly implemented, especially in children with a long duration of diabetes and those with peripheral neuropathy. [ABSTRACT FROM AUTHOR]

Purpose: The first aim of this study was to compare inferior tear meniscus height (TMH) measured by keratography and swept-source optical coherence tomography (OCT). Effect of locations of fluorescein instillation and subjects' subjective sensation, and the TMH results were also investigated. Methods: Forty-one eyes from 41 healthy adults had TMH randomly measured by keratography (K5M, Oculus, Germany) and swept-source OCT (Casia SS-1000, Tomey Corp, Japan) at baseline, followed by touching either the inferior bulbar or inferior palpebral conjunctiva, randomly assigned, with a moistened fluorescein strip. Two-way analysis of variance (ANOVA) was used to compare TMH obtained from the two devices and three measurement conditions. Subjective sensation of conjunctival touch was obtained through a 4-point scale with zero representing no sensation, and one to three representing ocular sensation in an ascending order. Results: Two-way ANOVA revealed no significant difference in TMH between keratography and swept-source OCT (Factor (devices): F = 0.579, p =.451) while there was a significant difference among fluorescein instillations (Factor (conditions): F = 10.146, p <.001). Baseline TMH was around 0.25 mm, and increased to around 0.28 mm after instillation of fluorescein sodium. Ocular sensation was similar between the two conjunctival touch, and TMH was not significantly associated with ocular sensation. Conclusions: Keratography and swept-source OCT provided similar TMH results. Applying fluorescein sodium through moistened fluorescein strip could over-estimate TMH by around 0.03 mm. Applying moistened fluorescein strip at bulbar or palpebral conjunctival led to similar subjective sensations and did not affect TMH measurement. [ABSTRACT FROM AUTHOR]

Purpose/Aim: Dry eye disease (DED), common and suboptimally treated, is in need of novel animal models to understand its pathophysiology and assess the efficacy and other parameters of new pharmacological agents for its treatment. The more than 10 rabbit models of DED described to date have significant limitations including induction of mild disease, lack of consistency, and off-target effects when chemical agents are used for disease induction. Our aim was to develop a new model of chronic DED in rabbits that overcomes the limitations of existing models. Materials and Methods: We performed a complete surgical resection of all orbital lacrimal glands (LGs; dacryoadenectomy) in normal adult New Zealand White rabbits. One week after removal of the nictitating membrane, we surgically removed the orbital superior LG, followed by removal of the palpebral superior LG, and finally removal of the inferior LG. Surgery was performed under anesthesia, required about 1 h/eye, and was well-tolerated. Results: Dacryoadenectomy induced severe DED, evidenced by >90% reduction in the tear break up time test, 50% reduction in the Schirmer tear test, 10% increase in tear osmolarity, and a marked increase in the rose bengal staining score. DED was sustained and essentially unchanged for the eight weeks of observation. Sham-operated rabbits showed no such changes, with the exception of a non-significant and transient reduction in the tear break up time test, a response to ocular surgery. Conclusions: This model of stable, chronic, predominantly aqueous-deficient DED recapitulates key clinical and histological features of human DED and is suitable for the study of ocular surface homeostasis, of the pathophysiology of DED, and of the efficacy of candidate drugs for DED treatment. [ABSTRACT FROM AUTHOR]

Purpose/aim: To assess the effectiveness of polytetrafluoroethylene (PTFE) tubes in the collection of human tears and meibum. Materials and methods: This was a prospective study that enrolled 10 healthy human subjects. Both the tear film and meibum were sampled using PTFE tubes in the right eye of all subjects. In the left eyes, either 5-µL or 1-µL glass microcapillary tubes were used to collect tears, and 0.5-µL glass microcapillary tubes were used to collect meibum. The lipids from the samples were extracted and analyzed using mass spectrometry (SCIEX TripleTOF 5600, Framingham, MA, USA). The absolute peak intensities of the omega-acyl hydroxy fatty acids (OAHFA), cholesterol esters (CE), and wax esters (WE) obtained for both methods were summed and compared between collection methods. Results: A total of 10 subjects completed the study (five female, mean age: 35.7 ± 7.9 years). Using the mass spectrometer output, the median (first quartile, third quartile) summed intensity units of OAHFA, CE, and WE collected associated with tears using PTFE were 516 (125, 1315), 7946 (2571, 19,915), and 38,892 (139,630, 174,082), all of which were significantly higher (all p ≤ 0.04) than those collected from glass microcapillaries (91 (41, 408), 2463 (1389, 6042), and 11,109 (7465, 37,371), respectively). The median summed intensity units of OAHFA, CE, and WE associated with meibum (1958 (1417, 3502), 11,726 (8434, 87,691), and 84,771 (52,657, 206,050), respectively) using PTFE were not significantly different (all p ≥ 0.13) than those associated with glass microcapillaries (1502 (699, 4407), 10,781 (3287, 38,205), and 77,381 (26,590, 178,213), respectively). Conclusions: PTFE tubes, which are thought to be lipophilic, were associated with more measurable lipids from the tear film than glass microcapillaries. There was no difference between collection methods in lipid profiles when used with meibum. [ABSTRACT FROM AUTHOR]

Purpose: To investigate Nerve Growth Factor (NGF) and nitric oxide synthase (iNOS) levels in tears obtained from Video Display Terminal (VDT) workers and correlate their expression with ocular signs and symptoms. Methods: A total of 120 VDT workers (62M/58F; 31-63 years old) and 40 age/sex matched no-VDT volunteers (19M/21F; 30-60 years old) were enrolled in the study. Participants completed the OSDI questionnaire and were subjected to clinical assessment of ocular surface status, including ocular symptoms and tear film parameters. NGF and iNOS levels were quantified in tear samples and their expressions correlated with OSDI, ocular symptoms and tear film parameters. Results: 59.17% of the studied population was symptomatic based on OSDI scores. Women were more commonly affected. The most frequent symptom was asthenopia and except for dryness, no differences were found between genders regarding other symptoms. A statistically significant decrease in NGF levels was found between normal and moderate (p < 0.05) and between mild and moderate (p < 0.05) OSDI grading. iNOS expression was increased in moderate OSDI grading compared to normals (p < 0.05). A negative correlation was found between NGF and respectively OSDI results, dryness and blurry vision (p < 0.05). No correlations were found among NGF, iNOS and ocular surface parameters (Schirmer, BUT, ocular surface staining). Conclusion: Our data suggest that NGF and iNOS levels contribute to VDT ocular discomfort. Further studies are required to better understand the relationship between NGF and iNOS in VDT ocular surface. [ABSTRACT FROM AUTHOR]

Dry eye (DE) is a multifactorial disorder of the ocular surface unit that results in eye discomfort, visual disturbance and ocular surface damage. It is one of the most common complaints in daily ophthalmic practice. The risk of DE increases with age in both sexes, while its incidence is higher among females. In addition, the condition of menopause in aging women may also contribute to DE onset or worsening as a consequence of an overall hormonal imbalance. Sex hormones play a key role in ocular surface physiology and they impact differently on ocular surface tissues. Reduced estrogen levels were historically thought to be responsible in age-related DE onset but more recent investigations have reconsidered the role of androgens that are present and exert a protective function on the ocular surface. Hormone levels themselves, withdrawal changes in hormone levels, and the changes in hormone-receptor responsiveness are all important factors but it remains to be fully elucidated how estrogen or androgen insufficiency act alone or together in a combined imbalance or interplay to raise the risk of disease. The purpose of this review is to briefly outline current scientific evidence on the influence of androgens and estrogens, on the Lachrymal and Meibomian glands and on ocular surface epithelia including conjunctival goblet cells during reproductive and menopausal periods. The role of sex steroids is also discussed in relation to the pathogenesis of different forms of DE and Sjogren's syndrome (SS). The impact of systemic hormone therapy (HT) in DE post-menopausal women still appears as a controversial issue, despite the many clinical studies. Finally, the outcomes of topical applications of steroid-based products are summarized, underlying the need for potential (tear) biomarker(s) in the rationale of DE-targeted therapy. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the present study was to evaluate the kinetics of single and multiple doses of topical, non-preserved voriconazole (VZ) in human eyes. Methods: For single dose kinetics, 119 patients undergoing cataract surgery were divided into group I and group II and each group received a single drop (30 µl) of either 1% or 0.1% VZ formulation. Aqueous humor was collected at designated time intervals. For multidose kinetics, a single drop of 1% VZ was instilled 5 times either hourly or every 2 hr. The aqueous humor was tested for VZ at the 5th hr and 9th hr, respectively, after initial instillation. The stability and efficacy of the reconstituted VZ formulations were also evaluated after 30 days. Results: Single dose ocular kinetics of 1% VZ resulted in a maximum mean aqueous concentration of 3.333 ± 1.61 µg/ml in 30 min whereas 0.1% showed a maximum mean aqueous concentration of 0.817 ±.36 µg/ml. In the multidose kinetic study, hourly and bi-hourly dosing resulted in mean aqueous concentrations of 7.47 ± 2.14 µg/ml and 4.69 ± 2.7 µg/ml, respectively. The reconstituted VZ formulations were stable at all studied temperatures, and their efficacy was maintained throughout the study period. Conclusion: The present study showed that the achieved mean concentration of VZ in both single dose and multi dose kinetic studies satisfactorily met the MIC90 for almost all causative fungal organisms. The frequency of instillation may be designed for an 'every 2 hr regimen' to maintain a therapeutic concentration for successful therapy. [ABSTRACT FROM AUTHOR]