Search

Paper spray high-resolution accurate mass spectrometry is a fast and versatile analysis method. This ambient ionization technique enables the quantitation of xenobiotics in complex biological matrices without chromatography or conventional sample extraction. The simplicity, rapidity, and affordability of the paper spray mass spectrometry (PS-MS) method make the technique especially attractive for clinical investigations where fast and affordable sample analysis is crucial. A new PS-MS method for the quantitation of voriconazole in equine tears was developed and validated. For a concentration range of 10 to 1000 ng/mL, good linearity (R 2  > 0.99), inter- and intra-run precision (coefficient of variation (CV) max. 11.9%), accuracy (bias of the nominal concentration ± 13.9%), and selectivity (signal areas of the double blanks represent 0.13 ± 0.05% of the lower limit of quantitation (LLOQ) signal in equine tears) were observed. The quantitation of voriconazole was based on three product ions and calculated relative to the isotope-labeled internal standard, voriconazole-d 3 , which had a final concentration of 250 ng/mL in the standards and samples. The matrix effect of the method showed an ionization suppression by reduction of the voriconazole response to 63.6%, 70.2%, and 81.9% for 30 ng/mL, 450 ng/mL, and 900 ng/mL in equine tears compared with voriconazole in solvent (methanol:water, 50:50, v:v). The method was used to analyze 126 study samples collected for a pharmacokinetic study investigating a novel approach for treatment of fungal keratitis in horses. Therefore, the integrity of the sample dilution (n = 6, CV 6.90%, and bias of nominal concentration + 8.40%) and the carryover effect (increase from 0.33 ± 0.21% to 1.33 ± 0.89% of the signal of the LLOQ) was further investigated. To our knowledge, this method is the first application of PS-MS for quantitation of drug concentrations in tears from any species.

Aim: Secretion of proteins into basal tears of Parkinson's disease (PD) patients may be altered by changes in nerve function. Materials & methods: Oligomeric α-Syn Oligo  and total α-Syn Total , CCL-2, DJ-1, LF and MMP-9 were measured in basal tears from 93 PD patients and 82 age- and sex-equivalent healthy controls. Results: α-Syn Total was decreased (p = 0.0043), whereas α-Syn Oligo (p < 0.0001) and the ratio of α-Syn Oligo /α-Syn Total (p < 0.0001) were increased in basal tears from PD patients compared with healthy controls. Area under receiver-operating curves of α-Syn Oligo and α-Syn Oligo /α-Syn Total contents were 0.70 (95% confidence limits: 0.621-0.774) and 0.72 (95% confidence limits: 0.642-0.792). Conclusion: PD patient basal tears may contain biomarkers that can be assayed noninvasively and inexpensively.

Purpose: To investigate the relationship between the duration of type 2 diabetes mellitus (DM) and the ocular surface, and to address the question of why some people with lengthy DM duration are asymptomatic, whereas some people with shorter DM duration have pain or discomfort in their eyes., Methods: Eighty-seven eyes of 87 subjects with different durations of DM and 49 eyes of 49 subjects without DM underwent Schirmer I test, tear film break-up time, sodium fluorescein staining and tear meniscus height (TMH) measurement, and completed the Standardized Patient Evaluation of Eye Dryness (SPEED) questionnaire. Corneal structure and function were assessed with in vivo confocal corneal microscopy and with a corneal sensitivity esthesiometer. Both corneal nerve fiber length and inferior whorl length (IWL) were assessed as indices for neural structure. Age and gender were matched between groups. HbA1c levels >7.8% and proliferative diabetic retinopathy were exclusion criteria., Results: In the DM group, compared with the non-DM group, the SPEED score was significantly higher (p = 0.013), and corneal sensitivity and IWL were lower (p < 0.001). Schirmer I test, corneal sensitivity and IWL differed significantly between the group with DM duration >10 years and the non-DM (control) group (p = 0.021, p < 0.001, p < 0.001, respectively). Schirmer I test and IWL were significantly lower in the group with DM >10 years than in the group with DM ≤10 years (p = 0.023, p < 0.001, respectively). Corneal sensitivity was positively correlated with IWL regardless of diabetes status., Conclusions: The lower SPEED score and asymptomatic feeling in people with a longer DM duration may be explained by the decreased IWL and reduced sensitivity., (Copyright © 2019. Published by Elsevier Ltd.)

Purpose: To evaluate tear film function in patients with diabetes mellitus (DM) using tear film osmolarity (TFO) measurements compared to other tear film function tests., Methods: DM patients without any history of ocular surface disorder but with potential effects on the tear film were enrolled in this cross-sectional study. Data including dry eye symptoms, duration of DM, stage of diabetic retinopathy and blood hemoglobin A1c levels were recorded. Tear film break-up time (TBUT) and basic tear secretion (Schirmer test) were assessed. TFO was determined using the Tearlab Osmolarity System. The outcome measures were the difference between the mean values of TBUT, basic tear secretion and TFO in both the study and control groups., Results: We recruited 51 DM patients and 20 control subjects with a mean age of 51.2 (range, 21 to 70) and 48.5 (range, 24 to 70) years, respectively. A total of 27 patients (53%) and 11 controls (55%) reported dry eye symptoms ( p = 0.668). The mean TBUT was 10.2 ± 4.8 seconds in the study group versus 10.5 ± 2.8 seconds in controls, which was not significantly different ( p = 0.747). The mean Schirmer test score was 8.1 ± 4.3 mm in the patients versus 10.1 ± 3.0 mm in the controls ( p = 0.069). The mean TFO was 294.1 ± 12.9 mosmol/L in the patients versus 291.4 ± 14.5 mosmol/L in the controls ( p = 0.456). It was significantly higher in patients with poor glycemic control determined by hemoglobin A1c > 8% ( p = 0.003). TFO had a positive correlation with the duration of DM ( p = 0.030) but not with the stage of diabetic retinopathy ( p = 0.944). However, TFO showed a significant relationship with dry eye symptoms ( p = 0.001)., Conclusions: TFO is impaired in patients with uncontrolled DM and is better correlated with glycemic control and dry eye symptoms than the TBUT and Schirmer tests., Competing Interests: No potential conflict of interest relevant to this article was reported., (© 2019 The Korean Ophthalmological Society.)

Eye problems are an adverse reaction sometimes found in chemotherapy. Although not life-threatening, they can reduce patients' quality of life. The highest incidence of eye problems is reported for the combination anticancer drug S-1 (tegafur-gimeracil-oteracil), and methods to prevent or treat the eye problems caused by this drug are presently lacking. To determine early detection methods and treatment for adverse ocular reactions, we measured changes in tear volume and levels of tegafur (FT) and 5-fluorouracil (5-FU), an active metabolite of FT, in the tears of patients with long-term use of S-1. A total of 11 patients receiving S-1 monotherapy as adjuvant chemotherapy after gastric cancer surgery were included. Tear volume and FT and 5-FU levels in tears were measured by liquid chromatography with tandem mass spectrometry during a maximum of 8 treatment cycles (48 weeks). For analysis, patients were divided into two groups: "watering eyes" (n=6, complaints of watering eyes at least once during the treatment period) and "no watering eyes" (n=5, no complaints of watering eyes). Both groups exhibited increased FT and 5-FU levels in tears upon initiation of S-1 treatment, and levels rapidly decreased upon discontinuation. Our findings suggest a relationship between FT level in tears and tear volume in patients with long-term S-1 use. The symptom of watering eyes may thus be linked to FT level in tears., Competing Interests: The authors declare that they have no conflict of interest.

Purpose: To determine the repeatability of tear ferning (TF) grading analysed by subjective and objective techniques, and its correlation with lipid layer thickness (LLT), non-invasive keratograph break-up time (NIKBUT), and ocular surface disease index (OSDI) comfort scores with and without ocular lubricants., Methods: A prospective, randomised, controlled clinical study was conducted. Eighteen healthy non-contact lens wearers aged between 18 to 45 years attended a total of three visits. They were randomly allocated to receive no drops on two occasions to examine method repeatability (visits A and B) or a 60 μL drop of Refresh® (visit C). At each visit, LLT and NIKBUT were assessed followed by basal tear collection. The TF pattern was established by pipetting one μL volume of tears onto a glass slide that was allowed to air-dry and imaged under a microscope. The resulting tear ferning pattern was determined using subjective grading and a novel computerized objective analysis technique that measured the local contrast of ferning contours., Results: Paired t-tests found that all measurements collected between eyes, on different days for visit A and B were not significantly different (p >0.05). Eyes and days were averaged and compared to visit C. Paired t-tests between the averaged baseline visits and visit C for LLT, NIKBUT including subjective and objective TF scores showed no significant difference (p>0.05). No significant correlation was shown between the TF scoring and OSDI, LLT or NITBUT (p>0.05). There was however a high significant correlation and agreement between the subjective and objective analysis techniques for TF grading., Conclusions: TF grade, LLT and NITBUT are repeatable. As with other ocular surface assessments, subjective and objective TF gradings did not significantly correlate with the measures of tear film stability or comfort. Lubricants had no effect on TF grade, LLT or NITBUT. The novel objective analysis technique is a promising candidate for a repeatable and unbiased assessment of tear ferning., (Copyright © 2019. Published by Elsevier Ltd.)

Purpose: To investigate the effects of a sea buckthorn oil and sodium hyaluronate-containing eyelid spray emulsion (SB spray) on dry eye., Methods: A randomized controlled study was carried out. Adults (25-70 years) with Ocular Surface Disease Index (OSDI) ≥20 and moderate or severe dryness, burning or grittiness of the eyes were included. In study part one (n = 2), SB spray was used on both closed eyelids four times in one day. In part two (n = 10), SB spray was used on one randomized eyelid, and a commercial reference spray on the other for nine days. In part three (n = 40), eyes were randomized to one eye receiving SB spray and an untreated control for 1.5 months. Dry eye tests were carried out at baseline, during, and at the end of each study section. Symptoms were recorded in questionnaires and daily logs., Results: In part one, the SB spray was well tolerated. In part two, OSDI decreased significantly (P = 0.022) in the SB spray eye compared to the reference spray, indicating a beneficial effect on symptoms. In part three, OSDI in the SB spray eye decreased significantly compared to the untreated control (P = 0.0007). The scores for dryness at the study end were lower in the SB spray eye compared to control (P = 0.0070). Symptom sums and frequencies of dryness (sum P = 0.0046, frequency P = 0.0016) and watering (sum P = 0.0003, frequency P = 0.013) in the daily logs were lower in the eye treated with SB spray., Conclusions: SB spray on closed eyelids relieved the symptoms of dry eye., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Contact lenses are ocular prosthetic devices used by over 150 million people worldwide. Primary applications of contact lenses include vision correction, therapeutics, and cosmetics. Contact lens materials have significantly evolved over time to minimize adverse effects associated with contact lens wearing, to maintain a regular corneal metabolism, and to preserve tear film stability. This article encompasses contact lens technology, including materials, chemical and physical properties, manufacturing processes, microbial contamination, and ocular complications. The function and the composition of the tear fluid are discussed to assess its potential as a diagnostic media. The regulatory standards of contact lens devices with regard to biocompatibility and contact lens market are presented. Future prospects in contact lens technology are evaluated, with particular interest given to theranostic applications for in situ continuous monitoring the ocular physiology., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Continuous glucose monitoring from sweat and tears can improve the quality of life of diabetic patients and provide data for more accurate diagnosis and treatment. Current continuous glucose sensors use enzymes with a one-to-two week lifespan, which forces periodic replacement. Metal oxide sensors are an alternative to enzymatic sensors with a longer lifetime. However, metal oxide sensors do not operate in sweat and tears because they function at high pH (pH > 10), and sweat and tears are neutral (pH = 7). Here, we introduce a non-enzymatic metal oxide glucose sensor that functions in neutral fluids by electronically inducing a reversible and localized pH change. We demonstrate glucose monitoring at physiologically relevant levels in neutral fluids mimicking sweat, and wireless communication with a personal computer via an integrated circuit board.

We report on a wearable tear bioelectronic platform, integrating a microfluidic electrochemical detector into an eyeglasses nose-bridge pad, for non-invasive monitoring of key tear biomarkers. The alcohol-oxidase (AOx) biosensing fluidic system allowed real-time tear collection and direct alcohol measurements in stimulated tears, leading to the first wearable platform for tear alcohol monitoring. Placed outside the eye region this fully wearable tear-sensing platform addresses drawbacks of sensor systems involving direct contact with the eye as the contact lenses platform. Integrating the wireless electronic circuitry into the eyeglasses frame thus yielded a fully portable, convenient-to-use fashionable sensing device. The tear alcohol sensing concept was demonstrated for monitoring of alcohol intake in human subjects over multiple drinking courses, displaying good correlation to parallel BAC measurements. We also demonstrate for the first time the ability to monitor tear glucose outside the eye and the utility of wearable devices for monitoring vitamin nutrients in connection to enzymatic flow detector and rapid voltammetric scanning, respectively. These developments pave the way to build an effective eyeglasses system capable of chemical tear analysis., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Elevated levels of acyl chain saturation of meibomian lipids are associated with enhanced tear film (TF) stability in infants to shortened TF breakup time with meibomian gland dysfunction. Thus, the effect of saturation on the surface properties of human TF lipids (TFLs) using a Langmuir surface balance and Brewster angle microscopy was studied. Lipid phase transitions were measured using infrared spectroscopy. The raise in the % of saturation resulted in thicker, and more elastic films at π = 12 mN/m, with the effects being proportional to the saturation level. At the same time, at lower (≤10 mN/m) π, the raise in saturation resulted in an altered spreading and modified structure of TFL layers. The strong impact of saturation on TFL surface properties correlated with a saturation induced increase of the TFL acyl chain order, phase transition temperature, and lipid-lipid interactions. The native TFL order and π max were significantly greater, compared with native meibum collected from the same individual. Aggregation of lipids on the tear surface due to saturation was not as significant as it was for meibum. Although the surface pressure/area isotherms for TFL were similar for meibum, differences in rheology and phase transition parameters warrant the study of both.

Background and Objectives : Topically administered antiglaucoma medications, especially those containing benzalkonium chloride (BAC), may cause local adverse effects and compromise ocular surface. The aim of the study was to assess the effect of topical prostaglandin F2α analogs (PGAs): preservative-free latanoprost, BAC-preserved latanoprost, preservative-free tafluprost, and BAC-preserved bimatoprost, on selected oxidative stress parameters in the tear film. Materials and Methods : The patients were divided into five groups: group C ( n = 25) control group-subjects who did not use topical antiglaucoma medications, group L ( n = 22)-patients using topical preservative-free latanoprost, group L+BAC ( n = 25)-patients using topical BAC-preserved latanoprost, group T ( n = 19)-patients using topical preservative-free tafluprost, and group B+BAC ( n = 17)-patients using topical BAC-preserved bimatoprost. The oxidative stress markers in the tear film samples were evaluated: total protein (TP) concentration, advanced oxidation protein products (AOPP) content, total sulfhydryl (-SH) groups content, the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), as well as Total Oxidant Status (TOS), Total Antioxidant Response (TAR), and Oxidative Stress Index (OSI). Results : The TP concentrations in the groups L, L+BAC, and B+BAC were statistically significantly higher in comparison with group C. The SOD and CAT activities in the groups L+BAC and B+BAC were statistically significantly higher when compared to group C. As compared to group C, AOPP and TOS were statistically significantly higher in all the study groups. OSI was found to be statistically significantly higher in the groups L+BAC, T, and B+BAC in comparison with group C. Conclusion : Use of topical PGAs by the patients with ocular hypertension or primary open-angle glaucoma is associated with increased oxidative stress in the tear film which is additionally exacerbated by the presence of BAC in the formulation.

Objective: Because of high variability, tear film osmolarity measures have been questioned in dry eye assessment. Understanding the origin of such variability would aid data interpretation. This study aims to evaluate osmolarity variability in a clinical setting., Material and Methods: Twenty dry eyes and 20 control patients were evaluated. Three consecutive osmolarity measurements per eye at 5min intervals were obtained. Variability was represented by the difference between both extreme readings per eye. Machine learning techniques were used to quantify discrimination capacity of tear osmolarity for dry eye., Results: Mean osmolarities in the control and dry eye groups were 295.1±7.3mOsm/L and 300.6±11.2mOsm/L, respectively (P=.004). Osmolarity variabilities were 7.5±3.6mOsm/L and 16.7±11.9mOsm/L, for the control and dry eye groups, respectively (P<.001). Based on osmolarity, a logistic classifier showed an 85% classification accuracy., Conclusions: In the clinical setting, both mean osmolarity and osmolarity variability in the dry eye group were significantly higher than in the control group. Machine learning techniques showed good classification accuracy. It is concluded that higher variability of tear osmolarity is a dry eye feature., (Copyright © 2019 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.)

Purpose: To investigate response profiles in the lacrimal functional unit of dry eye disease (DED) and healthy volunteers after exposure to a controlled adverse desiccating environment (CADE) by identifying groups of individuals with similar clinical and molecular changes., Methods: Clinical parameters and tear molecule levels of 20 mild-moderate DED patients and 20 healthy volunteers were evaluated pre- (baseline) and post-CADE exposure. Clustering based on relative change from baseline values was used to identify response profiles. One-vs-all logistic regression was used to identify baseline predictors for response clusters., Results: Four response profiles were identified. Cluster 1: tear break-up time (TBUT) decrease and matrix metalloproteinase 9 (MMP-9) increase. Cluster 2: marked increase in corneal staining, up-regulation of both MMP-9 and interleukin (IL)-6 levels, and down-regulation of epithelial growth factor (EGF). Cluster 3: increase in fractalkine, vascular endothelial growth factor (VEGF), MMP-9, IL-6, IL-8, IL-1 receptor antagonist (IL-1Ra) and RANTES (regulated on activation, normal T expressed and secreted) tear levels; and increased corneal staining and decreased TBUT and phenol red thread scores. Cluster 4: decreased single-item score dry eye questionnaire (SIDEQ) scores and increased corneal staining. Predictive models using baseline variables found that cluster membership depended on: corneal and conjunctival staining, SIDEQ score, interferon gamma-induced protein (IP)-10, VEGF, and IL-1Ra concentrations., Conclusions: The response of both mild-moderate DED and healthy asymptomatic individuals to environmental stress (CADE) can be predicted based on baseline (pre-exposure) clinical and tear molecular parameters. Thus, identifying individuals with a predictable response could improve patient enrollment in DED clinical trials., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objectives: We aim to use the ovariectomized cynomolgus monkey to observe the effect of long-term changes of sex hormone levels on ocular surface., Methods: Six healthy adolescent cynomolgus monkeys were randomly assigned to control and experimental groups (n=3/group). Bilateral ovariectomy was performed in experimental group, and sham operation was performed on control animals with their ovaries reserved. The concentrations of serum estradiol and testosterone in cynomolgus monkeys' lower-limb venous were detected by radioimmunoassay before surgery, and at 6, 12, 18, and 24 months after the surgery. Phenol red cotton thread test, tear osmolarity, corneal fluorescein staining, and conjunctival impression cytology were performed to evaluate the ocular surface conditions before surgery, and at 6, 12, 18, and 24 months after the surgery. The histological examinations of the bulbar conjunctiva and labial glands tissues were performed at 12 and 24 months after the surgery., Results: There were no significant differences in the serum level of estradiol and testosterone between the experimental and control groups before surgery, at 6, and 12 months after surgery (P>0.05). Serum level of estradiol and testosterone were significantly less in experimental versus control group at 18 and 24 months after surgery (P<0.05). There was no significant differences in phenol red cotton between the experimental and control groups before surgery, at 6, 12, 18, and 24 months after surgery (P>0.05). Tear osmolarity had no significant differences between experimental and control group before surgery (P>0.05), and it was significantly higher in experimental versus control group at all four time-points after surgery (P<0.05). The number of conjunctival goblet cells had no significant differences between experimental and control group before surgery, at 6 months after surgery (P>0.05), and it was significantly lower in experimental versus control group at 12, 18, and 24 months after surgery (P<0.05). There were no significant differences in the corneal fluorescein staining score between the experimental and control groups before surgery, at 6, 12, and 18 months after surgery (P>0.05), and it was higher in experimental than control group at 24 months after surgery (P<0.05). In addition, inflammatory cell infiltration in bulbar conjunctiva and labial glands tissues was observed in experimental group and was unobserved in control group at 24 months after surgery., Conclusions: Ovariectomy led to decreased sex hormone levels in cynomolgus monkey. In turn, tear osmolarity was increased, the number of conjunctival goblet cells were decreased, the corneal fluorescence staining was increased, and the pathological examination of the bulbar conjunctiva and labial glands tissues were abnormal, phenol red cotton thread test did not change significantly.

Objectives: To assess phosphate and osmolarity levels of chronically administered eye drops commercially available in Turkey., Materials and Methods: A total of 53 topical eye drops including 18 antiglaucoma drugs, 4 nonsteroidal anti-inflammatory drugs (NSAIDs), 10 corticosteroids, 7 antihistaminics, and 14 artificial tears identified using the Vademecum Modern Medications Guideline (2018) were included in the study. Phosphate levels were assessed using Roche Cobas C501 analyzer (Roche Diagnostics GmbH, Mannheim, Germany) and the respective kits. Osmolarity was assessed using Vescor Vapro 5600 vapor pressure osmometer (Sanova Medical Systems, Vienna, Austria). Mean phosphate and osmolarity levels were obtained after averaging three measurements. Eye drops were categorized as isoosmolar, hypoosmolar and hyperosmolar based on physiologic tear osmolarity range (296.5±9.8 mOsm/L)., Results: The highest phosphate concentration was found in the antiglaucoma group (20.3±35.4 mmol/L), followed by antihistaminics (17.3±17.9 mmol/L), corticosteroids (15.2±19.1 mmol/L), artificial tears (0.8±1.0), and NSAIDs (0.04±0.08). Percentage of medications in the hyperosmolar category was highest in the NSAI group (75%), followed by antihistaminics (43%), corticosteroids (20%), and antiglaucoma drugs (19%). Nearly all of the artificial tear formulations were in the hypoosmolar (71%) or isoosmolar (21%) categories., Conclusion: Approximately 40% of glaucoma medications and approximately 60% of corticosteroid and antihistaminic medications had a phosphate concentration higher than the physiologic tear phosphate level (1.45 mmol/L).

Purpose: Aging is a risk factor for dry eye disease. The aim of this study was to investigate if aging is associated with a range of signs of dry eye disease, including tear hyperosmolarity, reduced nerve density, and increased dendritic cell number, in mice., Method: Healthy C57BL/6 female mice, aged 2 months (young, n = 10) and 22 months (aged, n = 11) were used. Clinical assessments included corneal sensitivity (Cochet-Bonnet esthesiometry), tear secretion (Phenol red thread test), tear film osmolarity (TearLab osmometer), and corneal thickness (optical coherence tomography). The sum length of the corneal superficial terminals and sub-basal nerves, density of vertical nerve projections, and density and tree area of resident epithelial dendritic cells, were assessed using immunofluorescence and confocal microscopy., Results: Aged mice had significantly higher tear secretion, lower corneal sensitivity, and a thicker corneal stroma but thinner epithelium. There was no significant intergroup difference for tear osmolarity. Aged mice showed a significantly lower sum length of nerves in the superficial terminals and sub-basal plexus, relative to young mice. Dendritic cell density and morphology were similar in both groups., Conclusions: In mice, aging is associated with higher tear secretion and corneal epithelial thinning, together with lower corneal nerve density and sensitivity. However, aging was not significantly associated with changes to tear osmolarity or dendritic cell density or size, despite a significant reduction in total nerve length. These findings demonstrate that aged mice exhibit some changes to ocular surface parameters that parallel the anomalies evident in dry eye disease.

Purpose: Meibomian gland dysfunction is the main cause of dry eye disease (DED) and is traditionally managed using warm compress treatment (WCT). Vectored thermal pulsation treatment (VTPT) is a novel method for treating DED., Methods: We conducted a systematic review and meta-analysis of randomized controlled trials that compared the efficacy of VTPT and WCT in treating DED. The primary outcome was the gland function. The secondary outcomes were the tear breakup time, Schirmer test, tear osmolarity, lipid layer thickness, Standard Patient Evaluation for Eye Dryness, and the improvement of subjective symptoms as assessed by using the Ocular Surface Disease Index. PubMed, Embase, Cochrane Library, and ClinicalTrials.gov registries were searched for studies published before July 2018., Results: This study consisted of 4 trials with 385 patients. Significantly greater improvement was observed in meibomian gland function [mean difference (MD): 2.19 (95% confidence interval (CI), 0.95, 3.43)], tear breakup time [MD: 1.08 (95% CI, 0.06, 2.10)], and Standard Patient Evaluation for Eye Dryness [MD: -2.76 (95% CI, -4.22, -1.30)] at 2 to 4 weeks in the VTPT group than in the WCT group. A significantly greater decrease in Ocular Surface Disease Index was observed at 2 to 4 weeks [MD: -8.61 (95% CI, -13.62, -3.61)] and 3 months [MD: -6.92 (95% CI, -11.95, -1.89)] in the VTPT group than in the WCT group., Conclusions: A single 12-minute VTPT was more efficacious than traditional WCT in treating DED either in objective or subjective measurements. We recommended choosing an appropriate treatment after shared decision-making.

Botulinum toxin type A (BT-A) is used in the treatment of neuro-ophthalmologic disorders such as essential blepharospasm and facial hemispasm for more than 20 years. Although the long-term effect of repeated application of the BT-A was confirmed, the BT-A effect on tears production and retention is not clear. In our work we investigated whether applied BT-A in patients with blepharospasm and hemifacial spasm affect tears production. Tears quality was measured with Schirmers and tear osmolarity test during neuro-ophthalmologic diseases treatment, which was evaluated before and 14 days after application of BT-A (Botox inj, Allergan, Irvine, USA) into the orbicularis oculi muscle. BT-A doses of 16-18 U with unilateral and 32 to 36 U bilateral applications were used. The mean tear production in Schirmers test before BT-A application was 8.38 ± 0.63 mm, and 2 weeks after BT-A application was 7.12 ± 0,6 mm (n = 50). Tear osmolarity was 305.4 ± 9.2 mOsm before BT-A application, and 2 weeks after BT-A application it was 305.2 ± 8,6 mOsm (n = 13). We found significant difference between two groups in tear quantity (p &lt; 0.012), but not quality (p &gt; 0.05). Application of the BT-A reduced the amount of tears measured by Schirmers test. These results confirm rational basis of the empirical clinical experience where an artificial tears substitution is recommended for patients with neuro-ophthalmologic disorders treated by BT-A.

Purpose: To study whether some ocular surface alterations could be associated with contact lens (CL) wearers suffering from CL discomfort (CLD) detected using the Contact Lens Dry Eye Questionnaire (CLDEQ)-8., Methods: Forty-one soft CL wearers further classified into symptomatic CL wearers (SCLW) and asymptomatic CL wearers (ACLW) by the CLDEQ-8, and 20 non CL wearers (NCLW) were included. Tear osmolarity, slit-lamp biomicroscopy findings, tear film break-up time, corneal and conjunctival staining, and Schirmer test were performed 24 h after CL removal. Data were compared among groups using the analysis of variance and the Student t-test or the Kruskal-Wallis H and the Mann-Whitney U tests, applying the Bonferroni correction. Correlations between the CLDEQ-8 and the clinical signs were performed using the Spearman correlation coefficient., Results: Twenty-four SCLW, 17 ACLW and 20 NCLW were recruited. There were significant differences among groups for tear osmolarity (p < 0.001), limbal hyperaemia (p = 0.014), and tarsal hyperaemia (p = 0.031). Pairwise comparisons revealed that SCLW and ACLW had higher tear osmolarity (p < 0.003, both comparisons) and limbal hyperaemia (p = 0.027 and p = 0.048, respectively) than NCLW. Moreover, SCLW had higher tarsal hyperaemia (p = 0.030) than NCLW. No significant correlations were found (p > 0.05)., Conclusion: The CLDEQ-8 was ineffective to detect clinical alterations between SCLW and ACLW; therefore, the use of questionnaires alone remains being the best approach to detect CLD. The role of the tarsal conjunctiva in the development of CLD should be analyzed in future studies., (Copyright © 2018 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Background: The diagnosis of Parkinson's disease (PD) is still challenging and biomarkers could contribute to an improved diagnostic accuracy. Tear fluid (TF) is an easily accessible body fluid reflecting pathophysiological changes in systemic and ocular diseases and is already used as a biomarker source for several ophthalmological disorders. Here, we analyzed the TF of patients with PD and controls (CTR) to describe disease-related changes in TF and identify putative biomarkers for the diagnosis of PD., Methods: Unstimulated TF samples of a pilot cohort with 36 PD patients and 18 CTR were collected via Schirmer tear test strips and then analyzed via a Bottom-up liquid chromatography electrospray ionization tandem mass spectrometry (BULCMS) workflow, followed by functional analysis encompassing protein-protein interaction as well as cellular component and pathway analysis., Results: BULCMS analysis lead to the identification of 571 tear proteins (false discovery rate, FDR < 1%), whereby 31 proteins were exclusively detected in the PD group and 7 only in the CTR group. Whereas 21 proteins were significantly increased in the PD versus CTR groups, 19 proteins were significantly decreased. Core networks of proteins involved in immune response, lipid metabolism and oxidative stress were distinctly altered in PD patients., Conclusions: To our best knowledge, this is the first description of TF proteome in PD patients. Tear protein level alterations suggest the contribution of different disease-related mechanisms in ocular pathology in PD and propose candidate proteins to be validated as potential biomarkers in larger cohorts., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background and Objectives: The disposition of azithromycin in the human eye following topical administration has not been fully explored. Population pharmacokinetic (PopPK) modeling can allow useful conclusions to be drawn based on limited tear sampling data. The aim of this study was therefore to develop and evaluate a PopPK model of azithromycin eyedrops in tears, investigate typical model parameters, and identify potential covariates following single-dose ocular instillation., Methods: A total of 84 tear samples were obtained from 42 healthy volunteers at seven time points over 24 h following topical administration of azithromycin eyedrops (2.5 mL/25 mg). Azithromycin concentrations in the tears were determined using a validated LC-MS/MS assay. PopPK analysis was performed using nonlinear mixed-effects modeling. Intraocular pressure, tear secretion measurement, age, and gender were evaluated as possible covariates. Bootstrap and visual predictive checks were used simultaneously to evaluate the PopPK model. The dosage regimen was further estimated based on Monte Carlo simulation and the area under the curve/minimal inhibitory concentration., Results: A linear two-compartment first-order elimination model was found to best describe the pharmacokinetic profile of azithromycin in tears. None of the covariates had a significant influence on the typical model parameters. The final PopPK model was demonstrated to be suitable and effective according to bootstrap and visual predictive checks. Twice-daily instillation of azithromycin eyedrops would appear to provide the required antibacterial activity., Conclusion: A proposed linear two-compartment PopPK model of azithromycin eyedrops was found to be effective at describing the disposition of azithromycin in tears after ocular instillation.

A nanostructured catalyst is introduced that demonstrates peroxidase mimicking activity. It consists of nickel- and nitrogen-doped graphene nanotubes loaded with platinum nanoparticles. Pt-decorated Ni-doped nitrogen-rich graphitic nanotube (Pt/Ni@NGT) was synthesized using a two-step procedure in which the precursors were first refluxed to form a supramolecular assembly followed by a pyrolysis and leaching step to form nanotubes. Afterwards, Pt was decorated on the outer surface of nanotube by an ultrasound assisted method. Pt/Ni@NGT was characterized by XPS, TEM, SEM, and HAADF-STEM. The as-prepared Pt/Ni@NGT nanostructure was used for the detection of glucose via catalyzing the oxidation of a substrate, 3,3',5,5'-tetramethylbenzidine (TMB), to form a blue product (ox-TMB), thereby enabling colorimetric assay for enzymatically generated H 2 O 2 . The nanostructure exhibited excellent biocompatibility and led to highly efficient immobilization and retention of GOx. The method has a linear response in the 43 pM to 220 μM glucose concentration range, a detection limit as low as 1 pM and a limit of quantification of 3.4pM, along with good reproducibility(< 3%). A paper based visual microfluidic assay was also worked out that has an analytical range that extends from 0.1-50 mM. It is simple and rapid enough to be useful as a glucose home test.. The method was successfully applied to the determination of glucose in tear and saliva samples. Graphical abstract Graphene nanotubes doped with nitrogen and nickel (Ni@NGT) have been synthesized as the support to construct the unique Pt/Ni@NGT for providing artificial peroxidase activity for the GOx-based detection of glucose, which was further used for the construction of a glucose paper assay.

Investigating cytokines in tear fluid and saliva may offer valuable information for understanding the pathogenesis of primary Sjögren's syndrome (pSS). Cytokine profiles in both tear fluid and saliva of pSS patients, non-Sjögren's syndrome (non-SS) subjects with sicca symptoms, and healthy controls without sicca complaints were analysed. Furthermore, relationships associating the severity of clinical ocular and oral manifestations with the upregulated cytokines were assessed. In tear fluid, pSS patients showed elevated levels of IL-1ra, IL-2, IL-4, IL-8, IL-12p70, IL-17A, IFN-γ, IP-10, MIP-1b, and Rantes compared to non-SS subjects and healthy controls. The increased cytokine levels (except IP-10) correlated significantly with reduced tear production, less stable tear film, and greater ocular surface damage. In saliva, pSS patients had a higher IP-10 level, which correlated with higher candida score; and an elevated MIP-1a level, which correlated significantly with lower unstimulated and stimulated whole saliva secretion rates. The upregulated cytokines identified in tear fluid and saliva of pSS patients show a clear interplay between innate and adaptive immune responses that may contribute to disease pathogenesis. The increase of IP-10 and MIP in both tears and saliva further emphasises the essential role of macrophages and innate immunity in pSS.

Tear film breakup time (TFBUT) is an essential parameter used to diagnose dry eye disease (DED). However, a robust method for examining TFBUT in murine models has yet to be established. We invented an innovative device, namely, the "Smart Eye Camera", which addresses several problems associated with existing methods and is capable of evaluating TFBUT in a murine DED model. We compared images taken by existing devices and the Smart Eye Camera in a graft-versus-host disease-related DED murine model. We observed that the quality of the images obtained by the Smart Eye Camera were sufficient for practical use. Moreover, this new technique could be used to obtain measurements for several consecutive ocular phenotypes in a variety of environments. Here, we demonstrate the effectiveness of our new invention in the examination of ocular phenotypes, including TFBUT in a murine model. We highlight the potential for future translational studies adopting the Smart Eye Camera in clinical settings., Competing Interests: Patent applied by OUI Inc. (Smart Eye Camera, PCT/JP2019/002824. Inventors ES, HY, and AN. Tokyo, Japan). There are no other relevant declarations relating this patent. This does not alter our adherence to PLOS ONE policies on sharing data and materials. The other authors declare no competing interest associated with this manuscript.

Dry eye syndrome (DES) is a growing public health concern with a high global prevalence; however, the fundamental processes involved in its pathogenic mechanisms remain poorly understood. In the present study, we applied nanoscale liquid chromatography and quadrupole time-of-flight tandem mass spectrometry (nanoLC/Q-TOF-MS/MS) and ultraperformance LC/Q-TOF-MS/MS technologies on tear samples obtained from 18 dry eye patients and 19 healthy controls for integrated proteomic and metabolomic analyses. Overall, 1031 tear proteins were detected, while 190 proteins were determined to be significantly expressed in dry eye patients. Further functional analysis suggested that various biological processes were highly expressed and involved in the pathogenesis of DES, especially immune and inflammatory processes. In total, 156 named metabolites were identified, among which 34 were found to be significantly changed in dry eye patients. The results highlighted the key elements, especially inflammatory-related proteins and metabolites that played important roles in the development of DES. Further, the regulatory roles of primary pathways, including complement and coagulation cascades, glycolysis/gluconeogenesis, and amino acid metabolism, were also identified as processes involved in DES. Collectively, our work not only provided insight into the potential biomarkers of DES for diagnostic and prognostic purposes but extended our knowledge of the physiopathology of this syndrome.

Background: Vitamin D is a fat-soluble steroid hormone which can be converted into various forms and is of extreme physiological importance to our body. However, its functions and local metabolic pathways in some organs, such as the eye, have not yet been well studied. We aimed to verify the correlation between vitamin D levels in blood and tear fluid and the possibility of using tear fluid as a biological material for monitoring eye disorders in the future., Methods: The electrochemiluminescence method was used to examine blood and tear samples collected with Schirmer test strips from 21 individuals without ocular disease., Results: At the 95% confidence interval, mean tear fluid vitamin D = 37.8 ± 3.6 ng/mL, which is higher than the serum level, with a mean of 30.3 ± 7.7 ng/mL; Lin's concordance correlation coefficient = -0.018 (-0.174; 0.139), Pearson's coefficient = -0.070, and the Bland-Altman coefficient = -11.12 (-30.40; 8.16). Results were obtained using the program Stata version 11.0., Conclusion: It is possible to determine vitamin D levels in tear fluid using the electrochemiluminescence method, and as the results do not correlate with blood, there is possibility of using tear fluid as a biological matrix for detection of vitamin D, which may increase the possibilities of new studies in eye disorders., (© 2018 The Authors Journal of Clinical Laboratory Analysis Published by Wiley Periodicals, Inc.)

Aim: Meibomian gland dysfunction (MGD) is one of the most common disorders in ophthalmology. The aim of this study was to evaluate the use of this in vivo confocal microscopy (IVCM)-MGD description to classify patients affected by clinical MGD and measure the correlation with standard clinical criteria and subjective symptoms., Methods: One hundred eyes of 100 patients suffering from MGD and 15 eyes of normal subjects were included. A comprehensive evaluation with the ocular surface disease index (OSDI), Schirmer test, tear break-up time (TBUT), tear osmolarity, Oxford score, Meibomian gland expression, palpebral IVCM, and meibography was performed. Then each patient was classified using a new IVCM classification: type 0 for normality, type 1 for meibum obstruction, type 2 for inflammation, and type 3 for fibrosis., Results: The mean age of patients was 52 ± 20 years old, the OSDI was 38 ± 23, the BUT 5 ± 2.6 s, the Schirmer test 13 ± 7 mm, tear osmolarity 300 ± 11 osmol/L, the Oxford score 0.5 ± 0.6, the meibum expression score 1.7 ± 1.02, and the meibography score 1.3 ± 0.9. The IVCM MG classification of the 15 normal subjects was 0. For MGD patients, 29% were in type 1, 40% were type 2, and 31% were type 3. The patients in IVCM MG type 2 had a higher OSDI (p = 0.001) compared with the other types. There was a strong correlation between the IVCM score and the meibography score (r = 0.71 p < 0.0001)., Conclusion: This new IVCM classification provided a practical pathophysiological system for MGD. By giving objective criteria, this IVCM classification may help advance the understanding of patients' symptoms and enhance treatment effectiveness in MGD.

Glaucoma is a multifactorial neurodegenerative disease that causes impaired vision and, in advanced cases, blindness. The increasing prevalence of glaucoma due to an ageing population has necessitated the identification of suitable biomarkers for the early detection of the disease. Aqueous humour (AH) has been proposed as a source of biomarkers, but it can only be collected using a minor, yet invasive surgical intervention. Tears, however, are constantly available and can be collected any time via noninvasive methods. In order to examine the utility of tear as a surrogate for aqueous humour in biomarker development, we compared the levels of 27 cytokines and chemokines in paired samples of tear and aqueous humour using a Luminex multiplex immunobead-based technique. Significantly higher levels of cytokines in tear compared to aqueous humour were detected suggesting that tear and aqueous humour are not identical in terms of inflammation response. Furthermore, the levels of IFN-γ, GM-CSF and IL-5 in tear were significantly lower in patients who developed complications after one year, but no statistically significant changes in cytokine levels were observed in aqueous humour. These three molecules may have potential as predictive biomarkers for the appearance of late flap-related complications of trabeculectomy., (© 2019 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.)

Purpose: Lipid mediators of inflammation are a group of signaling molecules produced by various cells under physiological conditions and modulate the inflammatory process during various pathologic conditions. Although eicosanoids and F2-isoprostanes are recognized lipid mediators of inflammation, there is no consensus yet on the extraction and mass spectrometry (MS) method for their analysis in individual human tear samples. Thus, the aim of this study was to develop an optimal method for extraction of lipid mediators of inflammation in the tear film and evaluate MS techniques for their analysis., Methods: Basal tears were collected from each eye of 19 subjects using glass microcapillaries. Lipid extraction was performed using either varying concentrations of acidified methanol, a modified Folch method, or solid-phase extraction. Initially, an untargeted analysis of the extracts was performed using SCIEX TripleTOF 5600 mass spectrometer to identify any lipid mediators of inflammation (eicosanoids) and later a targeted analysis was performed using the SCIEX 6500 Qtrap to identify and quantify prostaglandins and isoprostanes. Mass spectra and chromatograms were analyzed using Peakview, XCMS, and Multiquant software., Results: Prostaglandins and isoprostanes were observed and quantified using the Qtrap mass spectrometer under multiple reaction monitoring (MRM) mode after solid-phase extraction. Extraction with acidified methanol along with the Folch method produced cleaner spectra during MS with the Triple time of flight (TOF) mass spectrometer. Lipid mediators of inflammation were not observed in any of the tear samples using the Triple TOF mass spectrometer., Conclusions: Solid-phase extraction may be the method of choice for extraction of prostaglandins and isoprostanes in low volumes of tears. The SCIEX Qtrap 6500 in MRM mode may be suitable to identify and quantify similar lipid mediators of inflammation.

Purpose: To compare the symptoms and signs of dry eye disease (DED) in children with systemic lupus erythematosus (SLE) with those in healthy children using common diagnostic tools., Methods: Prospective, observational, single-center cohort study. Thirty-four subjects with SLE and 15 healthy subjects were recruited from the Hospital for Sick Children in Toronto, Canada. Subjects underwent subjective and objective dry eye assessments using the Canadian Dry Eye Assessment (CDEA) questionnaire, tear film osmolarity, slit lamp examination, tear film break-up time, corneal fluorescein staining, Schirmer test 1, and conjunctival lissamine green staining., Results: No difference in symptoms was found between children with SLE and healthy children (CDEA score 6.4 ± 5.4 vs. 3.8 ± 3.2; P = 0.09). Corneal staining was more prevalent in children with SLE than in healthy children (58.8% vs. 20.0%; P = 0.01), and children with SLE had higher mean corneal fluorescein staining scores (1.7 ± 1.7 vs. 0.2 ± 0.4; P = 0.002). No statistically significant differences in tear osmolarity, inter-eye differences in tear osmolarity, tear film break-up time, Schirmer test 1, or lissamine green staining scores were observed between the 2 groups. In healthy children, CDEA scores weakly correlated with corneal fluorescein staining score (r = 0.53, P = 0.04). In children with SLE, no correlation between CDEA score and any of the diagnostic test outcomes was found., Conclusions: There is discordance between symptoms and signs of DED in children with SLE. Corneal fluorescein staining is essential for the diagnosis of DED in these children.

Lipids secreted from the meibomian glands form the outermost layer of the tear film and reduce its evaporation. Abnormal changes in the quantities or compositions of lipids present in meibomian gland secretions (meibum) are known to lead to dry eye disease, although the underlying mechanism is not yet well understood. The tree shrew is the non-primate mammal most closely related to humans. To assess the utility of the tree shrew as a model for the study of dry eye disease, we analyzed the lipid profile of tree shrew meibum using an untargeted ESI-MS and MS/MS all shotgun approach. The resulting lipidome shared many similarities with human meibum, while displaying some interesting differences. For example, several classes of lipids, including wax esters, cholesteryl esters, diesters, and (O-acyl)-ω-hydroxy fatty acids, had relatively longer chain lengths in tree shrew meibum. These increases in length may promote more effective reduction of tear evaporation in the tree shrew, which likely underlies the much longer blinking interval of this mammal. Our results suggest that the tree shrew could be an effective model for the study of dry eye., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: To examine the effect of pregnancy on the lacrimal system through tear osmolarity measurement and the Schirmer test., Material and Method: The study consisted of two groups of 30 women between 20 and 40 years old; the women in the study group were in their first trimester of pregnancy, and the women in the control group were not pregnant and did not have any diseases other than refractive error. Tear osmolarity measurement with the TearLab osmolarity system and tear function test Schirmer 1 were carried out on one, randomly chosen eye of each participant. The pregnant women's measurements were repeated on the same eye in their last trimester., Results: The study group's first trimester tear osmolarity measurement was 304.9 ± 8.0 mOsm/L, while their last trimester tear osmolarity measurement was 300.2 ± 7.1mOsm/L and the control group's was 306.3 ± 6.2 mOsm/L. There was a statistical difference between the study group's first and last trimester results and between the study group's last trimester and the control group's results (p < 0.05). The Schirmer test results were 18.1 ± 6.3 mm for the study group's first trimester, 16.6 ± 6.9 mm for the last trimester and 21.3 ± 9.0 mm for the control group. There was a statistically significant difference between the study group's last trimester results and the control group's Schirmer test results (p < 0.05)., Conclusion: Both the tear osmolarity values and Schirmer values were found to decrease significantly towards the end of pregnancy. These results suggest that decrease in both test results may play a protective role in the ocular surface during pregnancy., (Copyright © 2018 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: Sphingolipids (SPL) play roles in cell signaling, inflammation, and apoptosis. Changes in SPL composition have been reported in individuals with MGD, but associations between clinical signs of MGD and compositional changes in meibum SPLs have not been examined., Methods: Forty-three individuals underwent a tear film assessment. Groups were split into those with good or poor quality meibum. Meibum was collected then analyzed with liquid chromatography-mass spectroscopy to quantify SPL classes. Relative composition of SPL and major classes, Ceramide (Cer), Hexosyl-Ceramide (Hex-Cer), Sphingomyelin (SM), Sphingosine (Sph) and Sphingosine 1-phosphate (S1P) was calculated via mole percent., Results: 22 and 21 individuals were characterized with good and poor quality meibum, respectively. Individuals with poor quality were older (60 ± 8 vs 51 ± 16 years) and more likely to be male (90% vs 64%). Relative composition analysis revealed that individuals with poor meibum quality had SPL composed of less Cer (33.36% vs 49.49%, p < 0.01), Hex-Cer (4.88% vs 9.15%, p < 0.01), and S1P (0.16% vs 0.31%, p = 0.05), and more SM (58.67% vs 38.18%, p < 0.01) and Sph (2.92% vs 2.87%, p = 0.97) compared to individuals with good quality meibum. Assessment of the ratio of Cer (pro-apoptotic) to S1P (pro-survival) showed that individuals with poor meibum quality had a relative increase in Cer (495.23 vs 282.69, p = 0.07)., Conclusion: Meibum quality, a clinically graded marker of MGD, is associated with compositional changes in meibum sphingolipids. Further investigation of the structural and bioactive roles of sphingolipids in MGD may provide future targets for therapy., (Copyright © 2018. Published by Elsevier Inc.)

Interferometry is an optical technique that have been used to quantify the lipid layer of the precorneal tear film, and to investigate the relationship between lipid layer thickness and tear film evaporation. However, the relationship between lipid layer thickness and the rate of evaporation is far from consistent. One possible reason is the inherent limit of contemporary interferometric systems, which employ objectives with relatively long depth of focus (DOF) (>15 μm or more), which tend to collect excessive extra-planar noise. This limitation may negatively affect the accuracy of the characterization and thickness measurement of the lipid layer. The current system incorporated an objective with limited DOF (∼1.5 μm) into a custom-built optical microscope to image the tear film lipid layer in humans. An algorithm was also developed to process these images. One major outcome of this system is that thick lipid layers exhibit higher variation in thickness values than thin or normal-thickness lipid layers. The variations may reflect the structural differences of the lipid layer, which may offer a novel dimension to explain the missing correlation between lipid layer thickness and evaporation. In summary, the development of the high resolution microscopy system and associated data processing algorithm may provide new insights into the lipid layer structure, topography and their relation to the tear film evaporation rate., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: To explore the diagnostic utility of normal tear osmolarity in patients with symptoms suggestive of dry eye disease (DED)., Methods: Prospective observational cohort study of 100 patients that underwent tear osmolarity testing (TearLab ™ ) if they endorsed one or more symptoms of potential DED. Patients were included for the study if they had a normal tear osmolarity test (value <308 mOsm/L in each eye, and an inter-eye difference <8 mOsm/L). The main outcome measure was the presence of any alternate diagnosis to explain the patient's symptoms. Results were recorded and descriptive and univariate statistics were employed., Results: Mean tear osmolarity was 293.40 mOsms/L (±6.82), with a mean absolute difference of 2.85 mOsms/L (±1.98) between the eyes. A possible alternate diagnosis was established in 89% of patients with normal tear osmolarity testing. The most frequent diagnoses included anterior blepharitis (26%) and allergic conjunctivitis (21%)., Conclusions: Common symptoms of DED overlap significantly with a wide variety of other ocular surface diseases, and a normal tear osmolarity test should increase clinical suspicion for alternate causes of those symptoms. Anterior blepharitis and allergic conjunctivitis were the most common diagnoses made in symptomatic patients with normal tear osmolarity who may have otherwise been misdiagnosed and treated for DED., (Copyright © 2018 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: Our previous study demonstrated the drug reservoir function of human amniotic membrane (HAM) using stable moxifloxacin as a model drug. The purpose of the present study is to evaluate whether HAM can be used as a drug carrier for extended release of extemporaneous preparation of cefazolin., Methods: HAM Buttons (1 Control, 5 Test) were incubated in a freshly prepared (1 ml) sterile topical solution of cefazolin 5% (w/v) for 3 h and 24 h at two different temperatures. The groups were designated as follows: Group IA: Soaking duration 3 h at 4°C; Group IB: Soaking duration 3 h at room temperature; Group IIA: Soaking duration 24 h at 4°C; and Group IIB: Soaking duration 24 h at room temperature. The release kinetics of cefazolin from different groups of drug-laden HAM was studied for a period of 5 days. Samples were assayed for estimation of cefazolin content at different time intervals by High Performance Liquid Chromatography (HPLC) with Photodiode array (PDA) detector., Results: Three-hour cefazolin treatment with HAM at 4°C caused high drug entrapment (24%) compared to room temperature (11%; P < 0.005); however, the release kinetics was not significantly different between Group IA and IB as well as Group IIA and IIB up to the study period. Increase in drug treatment duration did not show increase in entrapment, but caused two-fold (IA Vs IIA) and 1.6-fold (IB Vs IIB) less drug entrapment at 4°C and room temperature, respectively., Conclusion: The results reveal that HAM may be a suitable drug carrier for extended delivery of fortified formulations without compromising stability., Competing Interests: None

Purpose: To enhance the understanding of dry eye (DE) in diabetes by evaluating the ocular surface characteristics and the levels of tear inflammatory cytokines., Design: Cross-sectional study., Methods: Subjects were divided into 4 groups: 32 patients in the diabetes with DE group; 24 patients in the diabetes without DE group; 28 patients in the nondiabetes with DE group; and 29 volunteers in the normal group. Ocular surface disease index (OSDI) was self-answered and ocular surface characteristics including tear film break-up time (BUT), Schirmer I test, corneal fluorescein staining (CFS), and corneal sensitivity were evaluated. Concentrations of epidermal growth factor (EGF), IL-17A, IL-1β, and tumor necrosis factor alpha (TNF-α) were measured by mutiplex bead analysis. Spearman correlations between cytokines and ocular surface parameters were calculated., Results: The level of EGF in tears significantly increased in the diabetes with DE group and positively correlated with the CFS and negatively correlated with the Schirmer I test in this group (P < .05). No differences were found in the levels of IL-17A, IL-1β, and TNF-α in the diabetes with DE and diabetes without DE groups compared to the normal group (P > .05). The nondiabetes with DE group showed increased levels of IL-17A, IL-1β, and TNF-α in tears compared to the normal group and the levels of IL-1β and TNF-α in tears positively correlated with CFS (P < .05)., Conclusions: Our study showed that levels of EGF in tears have potential to be the diagnostic biomarker of DE in diabetes. No differences of IL-17A, IL-1β, and TNF-α in tears were found between the diabetes with DE and normal group, suggesting different pathogenesis of diabetes DE vs nondiabetes DE., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Diabetes mellitus (DM) is a major health care burden associated with significant morbidity and serious impact on the quality of life. Estimating blood glucose levels is the currently employed method for screening for DM. Due to the invasive nature of access to blood glucose; new methods are being suggested that depend upon different targets than blood or another biochemical pathway altogether. But these are not cost effective and have inherent limitations related to public screening. We hypothesize a simple, non invasive and cheap paper strip method to estimate tear film glucose levels for screening purposes at community level. We also discuss the ideal properties of such a paper strip and the process of validation the technique should undergo before being employed for mass usage., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Purpose: The purpose was to evaluate if there are differences between tears of contact lens (CL) wearers of different materials detectable by measuring the hydrodynamic diameter of tear components through photon correlation spectroscopy (PCS)., Methods: Tears of 59 CL wearers and tears of 39 non-wearers were collected by glass capillary. Wearers were divided into groups depending on the CL material: (i) hydrogels of II FDA group (H-II, 15 subjects), (ii) hydrogels of IV FDA group (H-IV, 13 subjects), (iii) silicone hydrogels (SH, 31 subjects). PCS analyses were performed at 25 °C on samples diluted with deionized water with tear concentration (10 ± 2)% V / W to obtain, for each subject, the average hydrodynamic diameter (d H,avg ) of tear components by analyzing intensity fluctuations in time of scattered light., Results: Means of d H,avg calculated on each group were found, on increasing order, to be 256 nm (std dev 18 nm) for non-wearers, 297 nm (std dev 45 nm) for H-II, 360 nm (std dev 76 nm) for SH, and 391 nm (std dev 85 nm) for H-IV with statistical differences between each group of wearers compared to non-wearers and between groups of wearers except between SH and H-IV., Conclusions: PCS reveals the differences between tears of CL wearers of different materials, not only between tears of wearers and non-wearers., (Copyright © 2018. Published by Elsevier Ltd.)

Wearable biosensors are garnering substantial interest due to their potential to provide continuous, real-time physiological information via dynamic, noninvasive measurements of biochemical markers in biofluids, such as sweat, tears, saliva and interstitial fluid. Recent developments have focused on electrochemical and optical biosensors, together with advances in the noninvasive monitoring of biomarkers including metabolites, bacteria and hormones. A combination of multiplexed biosensing, microfluidic sampling and transport systems have been integrated, miniaturized and combined with flexible materials for improved wearability and ease of operation. Although wearable biosensors hold promise, a better understanding of the correlations between analyte concentrations in the blood and noninvasive biofluids is needed to improve reliability. An expanded set of on-body bioaffinity assays and more sensing strategies are needed to make more biomarkers accessible to monitoring. Large-cohort validation studies of wearable biosensor performance will be needed to underpin clinical acceptance. Accurate and reliable real-time sensing of physiological information using wearable biosensor technologies would have a broad impact on our daily lives.

Purpose: The purpose of this work was to optimize methodology to analyze the human tear film lipids by using untargeted, direct infusion electrospray ionization-mass spectrometry (ESI-MS) to establish the analytical approach for a large-scale clinical translational study of tear film lipids in ocular surface disease, particularly associated with the O-acyl-omega hydroxy fatty acids (OAHFAs)., Methods: Meibum and tear samples were collected from both eyes of five normal subjects without ocular disease using two different microcapillary collection tubes, glass and polytetrafluoroethylene (PTFE). An untargeted lipidomics approach was used to analyze the lipids in human tear and meibum samples using direct infusion ESI-MS in positive and negative ion modes. Direct and indirect quantification methods were evaluated., Results: The amount of OAHFAs measured in tears using these techniques was approximately 0.7-0.8% of the total lipids. More phospholipids, including phosphatidylcholine and sphingomyelin, were detected in the tear samples associated with glass microcapillaries compared to PTFE., Conclusions: Reliable assessment of lipids in small volumes of tear film is possible using high resolution, untargeted ESI-MS in positive and negative ion modes. Using this technique, the concentration of OAHFAs can be quantified, as can the presence of other polar lipids., (Copyright © 2019 Elsevier Inc. All rights reserved.)

NMR spectroscopy was used to measure hydrocarbon chain branching variability in meibum with age, gender and Meibomian gland dysfuction (MGD). A cohort of 65 meibum donors without dry eye and 31 donors with MGD was studied. Heteronuclear 2D NMR was used to confirm CH 3 resonance assignments allowing us to positively identify 23 of the 27 proton resonances of cholesteryl ester and 1 H resonances due to straight chain, iso-branched and anteiso-branched hydrocarbons. Meibum from donors without dry eye contained 57 ± 1% straight-chains, 23 ± 1% iso-branched chains and 20 ± 1% anteiso-branched hydrocarbon chains. Compared with meibum from donors without dry eye, meibum from donors with MGD contained less, 50 ± 2% straight-chains, more, 32 ± 2% iso-branched chains and the same amount, 18.0 ± 0.07%, of anteiso-branched hydrocarbon chains. Meibum hydrocarbon chain branching did not change with age between 22 and 68 years of age, nor was it influenced by gender. Based on previous studies, one would expect anteiso-branched chains would contribute to lowering the phase transition temperature of meibum, decrease the elasticity of the tear film lipid layer and increase the molecular area and spreading of meibum on the surface of the eye. Although we speculate that the observed differences in iso-chain branching do not influence tear film stability or rheology, the speculation has yet to be tested., (Copyright © 2018. Published by Elsevier Inc.)

Purpose: Numerous devices have been developed to warm the eyelid as a therapy for Meibomian gland dysfunction. The optimum temperature for such therapy was determined., Methods: Meibum lipid disorder versus temperature was calculated from previously published phase transition parameters measured using infrared spectroscopy. Phase transitions parameters were calculated from meibum obtained from donors with Meibomian gland dysfunction (M MGD ), donors who were susceptible to dry eye after hematopoietic stem cell transplantations (M HSCT ) and meibum from donors without dry eye (Mn)., Results: Heating Mn to 40 °C increases the lipid disorder by 20.4%-90%. Heating the meibum another 4° increases the disorder to 95%. M MGD is 73.2% disordered with no heating. Heating M MGD to 41.5 °C increases the disorder by 26.8%-90% disordered. Heating M MGD another 5.1 °C increases the disorder to 95%. As M HSCT is much more ordered, 56.9% disordered compared with M n and M MGD , a higher temperature above safety limits, 52 and 59 °C is need to disorder M HSCT to 90 and 95% disorder., Conclusions: Heating the eye lid above the phase transition temperature of meibum increases the disorder of meibum lipid which could ameliorate dry eye symptoms. The optimum temperature for disordering Mn and M MGD to 90% maximum disorder is 40 and 41.5 °C, respectively. Safety issues and discomfort should be considered in obtaining an optimal level of disorder, especially for severe cases of dry eye., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The symptom severity of patients with dry eye disease (DED) varies over a 24-hour period. It is typically worse upon waking than later in the morning and deteriorates towards the evening. Substantial differences in the characteristics and physical properties of the tear film, such as levels of inflammation, pH, osmolarity, volume and stability, also exist between night (sleeping) and day (waking), and over the course of the day itself. Data on diurnal variation in symptom severity and tear film characteristics have been reviewed to recommend a management strategy that supports the various needs of patients with DED over a full 24-hour period. Treatment strategies for DED must be matched to the variations in the severity of DED and to the environments that eyes are subjected to over a 24-hour period. While artificial tears are used to moisturise the ocular surface and reduce damage to the corneal epithelium during the day, gels are used at night-time; they are more viscous and have a longer ocular surface retention time than artificial tears. Several combinations of these products are currently available in tandem to support the 24-hour variation in tear film characteristics. The present review of published literature provides evidence that the approach of the daytime use of artificial tears to protect the eye from aggravating environmental factors in combination with the night-time use of gels to relieve more severe symptomatology. This, in turn, should provide optimal 'around-the-clock' DED management., (Copyright © 2018 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: To develop an in vitro model to determine pre-lens non-invasive break-up time (NIBUT) and to subsequently use this method to compare the NIBUT over contemporary daily disposable (DD) contact lenses (CL)., Methods: Three silicone hydrogel (SH) and two conventional hydrogel (CH) DD CLs were incubated in an artificial tear solution (ATS). A model blink cell (MBC) was utilised to mimic intermittent air exposure. CLs were repeatedly submerged for 3 seconds (s) and exposed to air for 10 s over periods of 2, 6, 12, and 16 hours (h). NIBUTs (n = 4) were determined out of the blister pack (T 0 ) and at the end of each incubation period., Results: Overall, nesofilcon A showed the longest NIBUTs (p < 0.001). At T 0 , CHs revealed significantly longer NIBUTs (p ≤ 0.001) than SHs. After 2 h, nesofilcon A showed the longest NIBUT, however, this was only statistically significant compared with delefilcon A (p ≤ 0.001). After 6 h, nesofilcon A NIBUT was significantly longer than all other CLs (p ≤ 0.001). Etafilcon A showed a significantly longer NIBUT (p ≤ 0.001) after 12 h and delefilcon A had the longest NIBUT (p ≤ 0.001) after 16 h. Statistically significant (p ≤ 0.05) changes of NIBUT within the lens materials varied between time points. After 16 h, all CLs showed significant reductions in NIBUTs (p ≤ 0.001) in comparison to T 0 ., Conclusion: NIBUT values reduced gradually over time and varying levels of deposition impacted measured pre-lens NIBUTs. While NIBUT of CH materials are longer immediately out of the blister pack, after tear film exposure, the NIBUTs obtained using this methodology became very similar., (Copyright © 2018 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Exocrine gland-secreting peptide 22 (ESP22) is a 10-kDa protein secreted in tears of juvenile mice. ESP22 inhibits sexual behaviors in adults, leading to a reduction in reproduction rate. We herein identified the 24 amino acid sequence within ESP22 that was essential for exhibiting sexual rejection activity. This synthesizable peptide can be useful for controlling mouse overpopulation.

We propose a noninvasive, self-diagnostic device that enables safe tear collection and glucose measurement. The device described herein was manufactured by tight assembly of a lid for tear collection in conjunction with a strip-type glucose sensor. The lid was designed to be in contact with the inferior palpebral conjunctiva for tear collection and was thus designed to possess a proper contact area and rounded boundaries to avoid eye tissue damage. For the strip-type glucose sensor, we employed a commercially available electrochemical sensor (Accu-Chek test strips), which was modified to reduce the volume of the reaction chamber (0.4 μl) for a small amount of collected tear fluid. When tested with in vivo animal models, the device was able to collect tear fluid in a relatively short time (<2 s) without causing eye tissue damage, and the device allowed the collected tear fluid to be delivered to the sensor for measurement of tear glucose concentrations. The blood glucose concentrations estimated with the tear glucose concentrations obtained with the device exhibited a high correlation with those actually measured with a clinically available glucometer (R 2  = 0.9617).

Metabolomics based on mass spectrometry represents an innovative approach to characterize multifactorial diseases, such as multiple sclerosis (MuS). To date, the most important biomarker source for MuS diagnosis is the cerebrospinal fluid. However, an important goal for research is to identify new molecules in more easily accessible biological fluids. A very interesting biofluid in MuS is represented by tears, considered as an intermediate fluid between the cerebrospinal fluid and serum. In this work, we developed a merged strategy for the analysis of lipids containing choline by Liquid Chromatography coupled to Tandem Mass Spectrometry (LC-MS/MS), as well as for the targeted analysis of free carnitine, acylcarnitines and aminoacids by direct infusion mass spectrometry. Samples for both metabolomics and lipidomics approaches were obtained in a single extraction procedure from tears of patients affected by MuS and healthy controls. Tear lipidomics showed 30 phospholipids significantly modulated and, notably, many sphingomyelins resulted lower in MuS. Moreover, the metabolomics approach carried out both on tears and serum highlighted the diagnostic potential of specific aminoacids and acylcarnitines. In conclusion, the metabolic profiling of tears appears to reflect the pathological conditions of the central nervous system, suggesting that the molecular repository of tears can be considered as a source of potential biomarkers for MuS.