Comparison of IgA,TNF-α and surface tension of the tear film in two different times of the day

PurposeThe main goal was to study the biochemical composition of the tear film in two different times of the day.MethodsTear samples were collected from 10 individuals, non contact lenses wearers, from the university population without pathologies. To assess daily variations in the tear film, samples were collected twice in the day, one early in the morning and another in the evening using capillary tubes. Tear protein profile was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), tumor necrosis factor α (TNF-α) and immunoglobulin A (IgA) were quantified by Enzyme-Linked ImmunoSorbent Assay (ELISA). Tear film stability was obtained through measurements of Non-Invasive Break Up Time and tear surface tension was measured by obtaining the Langmuir isotherms.ResultsThe stability of the tear film was higher in the morning than in the afternoon; corresponding to a higher value of surface tension in the afternoon. Protein electrophoresis tear profile is variable during the day as IgA concentration decreased from morning to afternoon (p < 0.05). TNF-α concentration also decreased, but there were not significant statistical differences (p = 0.089).ConclusionWe concluded that there are daily variations in the composition and properties of the tear film, indicating that changes occur without being caused by contact lenses wear or by the presence of ocular and systemic pathologies. Presence of TNF-α is not a direct indication of inflammatory pathology, since this cytokine was identified in relatively high amounts in subjects without inflammatory pathology.     

The effects of breaks on digital eye strain,dry eye and binocular vision: Testing the 20-20-20 rule

PurposeTo evaluate the benefits on the eyes of taking breaks based on the 20-20-20 rule.MethodsBespoke computer software using the laptop webcam to assess user breaks, eye gaze and blinking, and emitting personalized reminders of breaks based on the 20-20-20 rule, was downloaded onto the laptops of 29 symptomatic computer users. Digital eye strain (DES), binocular vision and dry eye were assessed before and after two weeks of using the reminders and one week after the discontinuation of the strategy. Binocular measurements included visual acuity, accommodative posture, stereopsis, fixation disparity, ocular alignment, accommodative facility, positive/negative vergences and near point of convergence. Symptoms were evaluated using the computer vision syndrome questionnaire, ocular surface disease index (OSDI), and symptom assessment in dry eye questionnaire (SANDE) versions one and two. Dry eye signs were assessed by measuring tear meniscus height, conjunctival redness, blink rate and incomplete blinking, lipid layer thickness, non-invasive keratograph break-up time, corneal and conjunctival staining and lid wiper epitheliopathy.ResultsA decrease in the duration of computer work and the duration of breaks, along with an increase in the number of breaks taken per day was observed as a result of the 20-20-20 rule reminders (p ≤ 0.015). No changes on any binocular parameter were observed after the management period (p ≥ 0.051), except for an increase in accommodative facility (p = 0.010). Dry eye symptoms and DES decreased with the rule reminders (p ≤ 0.045), although this improvement was not maintained one week after discontinuation (p > 0.05). No changes on any ocular surface and tear film parameter were observed with the rule reminders (p ≥ 0.089).ConclusionsThe 20-20-20 rule is an effective strategy for reducing DES and dry eye symptoms, although 2 weeks was not enough to considerably improve binocular vision or dry eye signs.     

Efficacy of a novel water propelled,heating eye mask massager on tear film and ocular adnexa

PurposeTo determine the effectiveness of the Aurai water propelled, heating Eye Massager (AEM) in managing dry eye disease and its effects on the ocular adnexa.MethodsThis prospective, randomised cross-over study enrolled 15 participants (aged 25.8 ± 5.45 years, 5 male). Participants wore a smart watch 24 h a day to track their sleeping cycle and heart rate for 4 weeks, using the AEM twice a day for 2 of those weeks. A cycle of 6 min of a controlled heat and vibration pattern in the morning and another cycle in the evening were applied with the AEM. Primary outcomes of symptomatology (Ocular Surface Disease Index (OSDI) and Symptom Assessment iN Dry Eye (SANDE)), tear film and ocular surface homeostasis markers (osmolarity, non-invasive breakup time (NIKBUT), tear meniscus height (TMH), lipid layer thickness and ocular staining) and safety measures (ocular redness and intraocular pressure), were assessed at baseline, after 2 weeks of AEM use and after 2 weeks of no treatment (in random-sequence). Sleeping tracking (ST) and heart rate/blood oxygen detection over these periods was also assessed.ResultsThere was a significant change in OSDI score from 34.3 ± 19.5 at baseline to 18.8 ± 17.5 after treatment (p = 0.001) and also for the SANDE (5.7 ± 2.4 vs 3.7 ± 2.1; p = 0.001). Heart rate was not affected by treatment (p = 0.956), nor sleep pattern (p = 0.529), but this varied by day (p = 0.001). Tear film and ocular surface homeostasis, the ocular adnexia and safety measures were not affected by treatment (p > 0.05).ConclusionThe Aurai water propelled Eye Massager may reduce the severity of symptoms of dry eye, but there were no detectable effects on tear stability and ocular surface disease from two weeks use.     

Genome‐wide expression profiling of the osmoadaptation response of Debaryomyces hansenii

The euryhaline marine yeast Debaromyces hansenii is a model system for the study of processes related to osmoadaptation. In this study, microarray‐based gene expression analyses of the entire genome of D. hansenii was used to study its response to osmotic stress. Differential gene expression, compared to control, was examined at three time points (0.5, 3 and 6 h) after exposure of D. hansenii cultures to high salt concentration. Among the 1.72% of genes showing statistically significant differences in expression, only 65 genes displayed at least three‐fold increases in mRNA levels after treatment with 2 M NaCl. On the other hand, 44 genes showed three‐fold repression. Upregulated as well as the downregulated genes were grouped into functional categories to identify biochemical processes possibly affected by osmotic stress and involved in osmoadaptation. The observation that only a limited number of genes are upregulated in D. hansenii in response to osmotic stress supports the notion that D. hansenii is pre‐adapted to survive in extreme saline environments. In addition, since more than one‐half of the upregulated genes encode for ribosomal proteins, it is possible that a translational gene regulatory mechanism plays a key role in D. hansenii's osmoregulatory response. Validation studies for ENA1 and for hyphal wall/cell elongation protein genes, using real‐time PCR, confirmed patterns of gene expression observed in our microarray experiments. To our knowledge, this study is the first of its kind in this organism and provides the foundation for future molecular studies assessing the significance of the genes identified here in D. hansenii's osmoadaptation. Copyright © 2009 John Wiley & Sons, Ltd.     

Endocrine responses in cows milked by hand and machine.

Plasma concentrations of oxytocin, prolactin, and cortisol were compared in five Swedish Red and White cows milked by hand versus machine. Cows were divided into two groups. One group was hand-milked; the other group was machine-milked. Treatments were switched every other day. The experiment was carried out for 6 d. Blood samples were taken prior to, during, and after milking and were assayed for hormones. More oxytocin and prolactin were released in hand-milked cows. There were no significant diurnal differences between the total amount of oxytocin released for the different treatments, but prolactin tended to be higher during hand-milking in the evening than in the morning milking. Cortisol concentrations were greater during hand-milking than during machine-milking. There were no significant treatment differences with regard to the total amount of cortisol released. During morning milking, cortisol concentrations were higher during hand-milking than during machine-milking. Our data show that hand-milking results in a pronounced and prolonged release of oxytocin and prolactin.     

Conjunctival prolapse during open eye scleral lens wear

PurposeTo investigate the incidence and peak elevation of conjunctival prolapse during short-term open eye scleral lens wear and its association with lens fitting characteristics.MethodsTen young, healthy adults (mean age ± SD, 30 ± 4 years) wore a high Dk sealed scleral lens for 90 min with an initial central post-lens fluid reservoir thickness defined as low (144 ± 23 μm), medium (487 ± 63 μm), and high (726 ± 55 μm). Optical coherence tomography was used to quantify limbal clearance, lens settling, and changes in conjunctival thickness.ResultsThe incidence of conjunctival prolapse was 37% across all fluid reservoir thickness conditions, with 80% of participants exhibiting conjunctival prolapse at least once. Prolapse was observed more frequently nasally (73%) than temporally (27%) (p < 0.01). The peak prolapse elevation did not vary with fluid reservoir thickness condition or anatomical location (both p > 0.05). For the low fluid reservoir thickness condition, eyes with conjunctival prolapse had greater initial limbal clearance (97 ± 38 μm compared to 43 ± 34 μm, p = 0.01) and more settling after 90 min of lens wear (−85 ± 30 μm compared to −34 ± 29 μm, p < 0.01). Greater limbal settling was associated with a higher peak elevation of the conjunctival prolapse (r = 0.48, p = 0.02), but not with landing zone tissue compression (r = 0.22, p = 0.33) or the initial or final limbal fluid reservoir thickness asymmetry (r ≤ 0.07, p > 0.05).ConclusionConjunctival prolapse was commonly observed during short-term sealed scleral lens wear in healthy eyes. The peak elevation of the conjunctival prolapse was associated with the extent of limbal settling, but not landing zone tissue compression or fluid reservoir thickness asymmetry.     

Improving ocular surface comfort in contact lens wearers

PurposeContact lens discomfort (CLD) is a major concern that can lead to the decreased or abandoned use of contact lenses. Contact lens users with dry eye disease are more likely to present with CLD. This study was conducted to evaluate the efficacy of a bioprotective preservative free, hypotonic, 0.15% hyaluronic acid (HA)-3% Trehalose artificial tear in managing dry eye symptoms in contact lens wearers.MethodsA prospective, single-arm, observational pilot study to evaluate the effectiveness of treatment with HA-Trehalose artificial tears in contact lens wearers (N = 33) aged 18–45 years with symptoms of ocular discomfort. Participants used a preservative-free, hypotonic HA-Trehalose artificial tear (1 drop/4 times per day) for 84 days. Participants were assessed using Visual Analogue Scale (VAS) for dry eye symptoms (pain, photophobia, dry eye sensation, blurry vision, foreign body sensation, itching, tingling/burning, and sticky eye feeling), Ocular Surface Disease Index (OSDI), Contact Lens Dry Eye questionnaire (CLDEQ-8), Berkley Dry Eye Flow-Chart (DEFC) on Day 0 and Day 84 and tear break-up time (TBUT), ocular surface staining with fluorescein and lissamine green, tear meniscus evaluation, and visual acuity on Day 0, 35, and 84.ResultsAll VAS symptoms (except tingling/burning and sticky eye feeling), OSDI, CLEDQ-8, and DEFC showed statistically significant (p < 0.05) improvement from baseline (Day 0) to Day 84. Similarly, corneal (fluorescein) and conjunctival (lissamine green) quality improved during the study (p < 0.05 at Day 84 versus baseline). Tear break-up time (TBUT), conjunctival (lissamine green) staining, and tear meniscus decreased but the changes were not statistically significant. Visual acuity did not change during the study. There were no ocular or systemic adverse events.ConclusionsThis study showed that the instillation of a preservative-free, hypotonic, HA-Trehalose artificial tear in contact lenses wearers with dry eye syndrome significantly improved symptoms and reduced associated signs such as corneal and conjunctival staining.     

Rationale for 24-hour management of dry eye disease: A review

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.     

Diagnostic accuracy of non-invasive tear film break-up time assessed by the simple manual interferometric device

AimTo determine the diagnostic accuracy of non-invasive tear film break-up time (NIBUT) measured by the handheld lipid layer examination instrument.Methods108 patients were enrolled in this cross-sectional study and divided into two groups: patients with dry eye (n = 57) categorized by the presence of dry eye symptoms obtained by Schein Questionnaire and minimally-one objective dry eye sign (tear film break-up time <10 s or corneal, conjunctival and lid margin fluorescein staining), and healthy subjects (n = 51).ResultsDry eye subjects had significantly shorter NIBUT than healthy subjects (6 s vs 20 s, p < 0.001). Logistic regression analysis showed that shorter NIBUT values were excellent indicators of dry eye disease (p < 0.001), with consistency and no significant difference between measurements, even after standardizing the results for age and sex. NIBUT cut-off point to distinguish dry eye from healthy subjects was 12 s (sensitivity 90.2 %, specificity 88.5 %, PPV 92.5 %, NPV 85.2 %, LR +7.82, LR− 0.11, DOR 70.92, DE 89.6 %). Good, but lower accuracy was observed at cut-off value of 10 s (sensitivity 87.8 %, specificity 88.5 %, PPV 92.3 %, NPV 82.1 %, LR+ 7.61, LR− 0.14, DOR 55.2, DE 88.1 %). The area under the ROC curve (AUC) of 0.944 classified NIBUT as a diagnostic test with very high accuracy.ConclusionThis study showed a high diagnostic accuracy of NIBUT measured by the handheld lipid layer examination instrument. This simple, reliable, objective and available instrument might regularly take place in routine, standard dry eye diagnostic and can be used by almost every eye specialist.     

Association study of single nucleotide polymorphisms in IL-10 and IL-17 genes with the severity of microbial keratitis

PurposeExploratory analysis to assess the association of single nucleotide polymorphisms (SNPs) in the interleukin (IL) 10 and IL-17 genes with severity of contact lens keratitis.MethodsThis was a retrospective case control study of 88 contact lens keratitis cases (25 severe) and 185 healthy contact lens wearers recruited from studies conducted at Moorfields Eye Hospital and in Australia-wide during 2003–2005. Buccal swab samples were collected on Whatman FTA cards and mailed by post for DNA extraction and SNP genotyping. IL-10 (rs1800871; rs1800896; rs1800872) and IL-17 (rs1800871; rs1800896; rs1800872) SNPs were screened by pyrosequencing. Genetic association analyses were performed via Cochran-Armitage trend tests and logistic regression models using PLINK software.ResultsNone of the SNPs tested showed evidence of association with severity of contact lens keratitis at P < 0.05. Nevertheless, minor allele G in SNP rs2397084 of the IL-17F gene was associated with increased risk of severe MK, with OR=2.1 (95% CI=0.9-4.8, P = 0.066).ConclusionOur study cannot exclude with confidence that genetic variation in the IL-17 F proinflammatory cytokine is associated with more severe outcomes of MK. However, there is general body of information that the IL-17 pathway is important in the mechanisms of MK. Studies with larger power and the expanded array of laboratory tools will elucidate the exact role of IL-17 in MK.     

Effect of hyperketonemia on the diurnal patterns of energy-related blood metabolites in early-lactation dairy cows

Most dairy cows experience a period of energy deficit in early lactation, resulting in increased plasma concentrations of nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHB). Our objectives were to determine (1) the diurnal variation in plasma BHB and NEFA, (2) the correlation between plasma NEFA and BHB when accounting for diurnal changes, and (3) the effect of hyperketonemia (HYK) on the diurnal pattern of blood metabolites. Jugular catheters were placed in 28 multiparous Holstein cows between 3 and 9 days in milk, and blood samples were collected every 2 h for 96 h. Cows were retrospectively classified as HYK positive (HYK; n = 13) if they had plasma BHB concentrations ≥1.2 mmol/L for ≥3 study days, or HYK negative (non-HYK; n = 15) if they had plasma BHB concentrations ≥1.2 mmol/L for ≤2 study days. Generalized linear mixed models were used to analyze concentrations of analytes over time and differences in metabolites between HYK groups. The correlation between total plasma NEFA and BHB was analyzed by calculating the area under the curve for plasma NEFA and BHB for all cows. Plasma NEFA reached a peak approximately 2 h before morning feed delivery, falling to a nadir in the late evening. Plasma BHB was at a nadir at the time of morning feed delivery, peaking 4 h later. We observed a strong positive correlation between daily plasma NEFA and BHB. Additionally, HYK cows had greater concentrations of plasma NEFA and BHB than non-HYK cows. The HYK cows also experienced a greater magnitude of change in BHB throughout the day than the non-HYK cows. Our results suggest that the time relative to feeding should be considered when analyzing plasma metabolites, as classification of energy status may change throughout a day.     

Masked comparison of two silicone hydrogel bandage contact lenses after photorefractive keratectomy

PurposeTo compare the efficiency and safety of two bandage contact lenses after photorefractive keratectomy (PRK).MethodsIn this double-blind study, 45 patients (90 eyes) received PRK in both eyes and wore bandage contact lenses (BCLs), PureVision (Bausch & Lomb, Rochester, NY, USA) in one eye and PureVision2 (Bausch & Lomb, Rochester, NY, USA) in the other eye, randomly assigned. The medication regimen after surgery was the same for both eyes. The epithelial defect's size, conjunctival hyperemia and lens centration were graded objectively using slit-lamp biomicroscopy on days 1, 3 and 5 after surgery. Also ocular symptoms of discomfort including tearing, photophobia, foreign body sensation and visual fluctuations were assessed subjectively at each visit.ResultsThe mean epithelial defect size on the first day after operation was similar in eyes fitted with PureVision (30.08 ± 5.30 mm²) and PureVision2 (30.25 ± 5.72 mm²) lenses. (p = 0.79) Contact lens deposits and bulbar hyperaemia on days 1 and 3 after PRK were similar between the two eyes, but were significantly greater on day 5 for PureVision2 lenses. (p = 0.02; p = 0.04 respectively) There was no difference in contact lens decentration, and discomfort symptoms including pain, tearing, foreign body sensation, photophobia and visual fluctuations between the eyes fitted with PureVision and PureVision2. (p > 0.05)ConclusionsPureVision and PureVision2 contact lenses are equivalent as bandage lenses in important aspects such as corneal re-epithelialization and subjective comfort., although PureVision2 led to a higher incidence of contact lens deposits and conjunctival hyperemia early post-PRK.     

Corneal epithelial thickness and corneal curvature changes during the day: The effects of daily disposable contact lens wear

PurposeTo evaluate the changes in corneal epithelial thickness and corneal anterior and posterior curvatures during the day, and the effect of wearing daily disposable soft contact lenses.MethodsThirty-two healthy volunteers were enrolled in a randomized crossover study. At the baseline visit, corneal and epithelial thickness maps (OCT; Optovue, Inc., Fremont, CA, USA) and keratometric measurements (Pentacam, Oculus, GmbH, Germany) were performed in the morning and in the afternoon (8 hours after). Then, each subject was fitted with the following brands of daily disposable contact lenses in random order: Dailies Total 1 (Delefilcon A), Dailies Aqua Comfort (Nelfilcon A), TruEye (Narafilcon A) and Biotrue Oneday (Nesofilcon A) on different days. All fitted lenses had a power of −3.00 diopters (D). Measurements were repeated before putting the contact lens on and after an-eight-hour contact lens wear.ResultsWith no lens wear, the anterior topographic indices showed significant steepening [Kflat: p < 0.0001; Ksteep: p < 0.0001 and maximum keratometry value (Kmax): p = 0.04] and the corneal thickness significantly decreased in the central and temporal portion of the cornea in the afternoon. There were no significant changes in the posterior topographical indices and corneal epithelial thickness. With contact lens wear, no significant change occurred in the corneal and epithelial thickness, and the anterior and posterior curvatures during the day (all p values >0.05). There was no statistically significant difference in the epithelial thickness among the groups wearing different contact lens types (p > 0.05).ConclusionsAnterior corneal topographic indices steepen depending on the natural diurnal variations. Daily wear of soft contact lenses appears to mask this steepening. The corneal epithelial thickness is not affected by daily disposable soft contact lenses.     

Microarray studies on the genes responsive to the addition of spermidine or spermine to a Saccharomyces cerevisiae spermidine synthase mutant

The naturally occurring polyamines putrescine, spermidine or spermine are ubiquitous in all cells. Although polyamines have prominent regulatory roles in cell division and growth, precise molecular and cellular functions are not well‐established in vivo. In this work we have performed microarray experiments with a spermidine synthase, spermine oxidase mutant (Δspe3 Δfms1) strain to investigate the responsiveness of yeast genes to supplementation with spermidine or spermine. Expression analysis identified genes responsive to the addition of either excess spermidine (10^?5 M ) or spermine (10^?5 M ) compared to a control culture containing 10^?8 M spermidine. 247 genes were upregulated > two‐fold and 11 genes were upregulated >10‐fold after spermidine addition. Functional categorization of the genes showed induction of transport‐related genes and genes involved in methionine, arginine, lysine, NAD and biotin biosynthesis. 268 genes were downregulated more than two‐fold, and six genes were downregulated > eight‐fold after spermidine addition. A majority of the downregulated genes are involved in nucleic acid metabolism and various stress responses. In contrast, only a few genes (18) were significantly responsive to spermine. Thus, results from global gene expression profiling demonstrate a more major role for spermidine in modulating gene expression in yeast than spermine. Copyright © 2009 John Wiley & Sons, Ltd.     

Predicted intake of trace elements and minerals via household drinking water by 6-year-old children from Krakow (Poland). Part 4: Copper

The aim of this study was to assess exposure of children to copper (Cu) from household drinking water (DW). DW samples were collected between 1997 and 2004 in ～650 households and pre-schools using a double-sampling method (morning – W1; evening – W2). The study group comprised ～300 children (5–7 years old) living in Krakow (urban, peripheral) and rural areas in southern Poland. Cu concentrations were determined by flame atomic absorption spectrometry. There was no significant relationship between the sampling period and Cu concentration, but statistically significant differences were found between urban and non-urban (rural, peripheral) sites and between morning and evening samples. Geometric means of Cu concentration in evening DW (95% confidence interval, in μg L^?1) were 8 (1–110), 20 (1–274) and 12 (0–364) in urban, peripheral and rural sites, respectively. DW contamination after overnight standing was comparable in all sites (average increase ～20 μg Cu L^?1). The adopted threshold of 100 μg Cu L^?1 was exceeded in evening DW by 3.6 and 15% in urban and non-urban households, respectively. Exceedance of the EC limit (2 mg L^?1) was not significant. The mean predicted contribution of evening DW to Cu intake by children were 18–37 μg day^?1 or 0.8–1.6 μg kg^?1 bw day^?1 but were 2–3-fold higher for morning DW. The Polish RDA (1 mg Cu day^?1) was exceeded for morning (evening) DW in 3.7 (0.2)% of children, with a mean intake of 159 (118)% of RDA. The observed copper levels and predicted intakes can be considered low and should not raise nutritional or toxicological concerns for the age group studied. Nevertheless, due to overnight contamination, the suggestion that the stagnant portion of drinking water should be discarded remains valid.     

Effect of scleral lens use on conjunctival microbiota

AimThis study aimed to investigate the effect of scleral lens (SL) use on conjunctival microbiota.MethodA total of 26 eyes of 26 patients using an SL and 25 eyes of 25 healthy controls were included in the study. The samples were obtained from the lower fornices of the eyes using sterile swabs. For the bacteriological examination, a bacterial culture was obtained by inoculating the samples on chocolate agar, blood agar, MacConkey agar, and fluid thioglycollate medium. After 24–48 h of incubation at 37 ⁰C, the growth of different colonies of bacteria was identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (Bruker MALDI Biotyper).ResultsThe mean age of the study group was 41.6 ± 19.1 years (18–65); the mean age of the control group was 40 ± 6 (21–62) (p = 0.69). There were 10 male patients and 16 female patients in the study group and 9 male patients and 16 female patients in the control group (p = 0.86). The mean duration of SL use was 13.7 ± 13.4 months (1–42 months). No bacterial growth was observed in 17 (65.4 %) of the 26 eyes in the SL group and 5 (20 %) of the 25 eyes in the control group (p = 0.001). The most commonly observed microorganisms were Staphylococcus epidermidis (S.epidermidis) and Staphylococcus aureus (S.aureus) in both groups.ConclusionSL users were found to have a higher rate of culture negativity in comparison to the healthy controls, suggesting that SLs have a significant effect on conjunctival microbiota.