Tear Osmolarity Research Articles

Tear Osmolarity and Ocular Surface Parameters as Diagnostic Markers of Ocular Graft-Versus-Host Disease

To evaluate the diagnostic value of tear osmolarity and several ocular surface parameters in screening for ocular surface alterations in ocular graft-vs-host disease (GVHD) patients. Case-control study. Sixty-three patients with ocular GVHD and 74 healthy participants were screened for ocular surface changes using the Ocular Surface Disease Index (OSDI), tear osmolarity, Schirmer test, tear break-up time (TBUT), and fluorescein corneal staining. The severity of ocular GVHD was diagnosed according to the National Institutes of Health (NIH) grading system. The diagnostic sensitivity and specificity and cutoff values were determined for each ocular parameter using a receiver operating characteristic (ROC) curve and area under the curve (AUC) analysis. Significance was defined at P < .05. The tear osmolarity, corneal staining score, and OSDI score gradually increased as the severity of ocular GVHD increased, and Schirmer value gradually decreased as the GVHD grade increased in severity. The Schirmer test showed greatest diagnostic sensitivity and specificity for ocular GVHD (92.1% sensitivity, 85.7% specificity, cutoff = 9 mm), followed by the TBUT (87.3% sensitivity, 75.0% specificity, cutoff = 6 s), tear osmolarity (98.4% sensitivity, 60.7% specificity, cutoff = 311 mOsm/L), corneal staining score (66.7% sensitivity, 82.1% specificity, cutoff = 2), and OSDI score (77.8% sensitivity, 66.1% specificity, cutoff = 20.8). Multiple diagnostic modalities should be used to detect ocular surface changes in GVHD patients. The severity of ocular GVHD can be effectively monitored using tear osmolarity; however, additional studies are required.

Comprehensive evaluation of dehydration impact on ocular tissue during Ramadan fasting

Purpose The present study aimed to review the effect of dehydration during Ramadan on the health and ocular parameters leading to changes in eye function. Methods Articles included in the study were taken from PubMed, Ovid, Web of Science and Google Scholar up to 2014. Related articles were also obtained from scientific journals on and vision system. Results Dehydration and nutrition changes in Ramadan cause an increase in tear osmolarity, ocular aberration, anterior chamber depth, IOL measurement, central corneal thickness, retinal and choroidal thicknesses, and also a decrease in IOP, tear secretion, and vitreous thickness. Conclusion Much research related to the effect of dehydration on ocular parameters during Ramadan exists. The findings reveal association with significant changes on ocular parameters. Thus, it seems requisite to have a comprehensive study on fasting and ocular parameters”, which will be helpful in making decisions and giving plan to the patients.

Corneal health and contact lens wear: Ion chromatography as an electrolyte probe

Purpose: Tear osmolarity and the concentrations of ocular electrolytes in the eye are known to influence corneal health. Similarly, corneal cells are known to be sensitive to changes in electrolyte balance. Ion transport through contact lenses can influence electrolyte equilibration between preand post-lens tear film. Until now no suitable technique has been identified to quantify these effects. This study utilised ion chromatography to examine multiple ion transport through lenses and the measurement of ex-vivo tear samples. Methods:AmodifiedDionex ion chromatographenabled simultaneous measurement of Na+/K+/Ca2+ and Mg2+ concentrations in both single (5 l) tear samples and lens/membrane permeation studies. In addition to commercial contact lenses, conventional HEMA membranes (40% water) and acrylamide-based corneal model hydrogel membranes (ca 90% water) were mounted in purpose-designed permeability cells and the transport of mixed electrolytes (e.g. 0.25M NaCl, KCl and CaCl2) measured. Results: In baseline studies, the relative ratio of the main tear cations measured in healthy tear film samples was found to be Na+:K+:Ca2+:Mg2+ =140:11:1.2:1. This accord with the observation that the range of K+ concentrations in tears (ca 15–30mM) is high and Ca2+ and Mg2+ concentrations (ca 0.4–0.8 and 0.5–1.1mM) is low, relative to serum. The relative permeability coefficients of lenses and membranes were consistent (i.e. NaCl <KCl » CaCl2) ranging between 141.2×10−7: 148.2×10−7: 98.2×10−7 cm2/s (±5% for 90% acrylamide based hydrogel) and 2.8×10−7:3.2×10−7:0.7×10−7 cm2/s (±5% for 40% HEMA hydrogel). Conclusions: Ion chromatography enables tear electrolytes to be accurately monitored in 5 l samples. This, coupled with tear envelope sampling, provides a means of correlating clinical signs and symptoms with post-lens electrolyte concentrations and the ion permeability coefficients of individual lenses. Anisa Mahomed completed an MEng in Chemical Engineering and then obtained her PhD from the Biomaterials Research Group at Aston University. Her thesis discussed the aspects of the fabrication of novel hydrogels for dermal and ocular applications. She is currently a postdoctoral researcher and her interests include investigating factors that affect the uptake, release and transport of various species from hydrogels and developing analytical techniques to enable the understanding of clinical adverse events related to the use multipurpose solutions.

Plasma protein influx in contact lens wear

Purpose: Tear osmolarity and the concentrations of ocular electrolytes in the eye are known to influence corneal health. Similarly, corneal cells are known to be sensitive to changes in electrolyte balance. Ion transport through contact lenses can influence electrolyte equilibration between preand post-lens tear film. Until now no suitable technique has been identified to quantify these effects. This study utilised ion chromatography to examine multiple ion transport through lenses and the measurement of ex-vivo tear samples. Methods:AmodifiedDionex ion chromatographenabled simultaneous measurement of Na+/K+/Ca2+ and Mg2+ concentrations in both single (5 l) tear samples and lens/membrane permeation studies. In addition to commercial contact lenses, conventional HEMA membranes (40% water) and acrylamide-based corneal model hydrogel membranes (ca 90% water) were mounted in purpose-designed permeability cells and the transport of mixed electrolytes (e.g. 0.25M NaCl, KCl and CaCl2) measured. Results: In baseline studies, the relative ratio of the main tear cations measured in healthy tear film samples was found to be Na+:K+:Ca2+:Mg2+ =140:11:1.2:1. This accord with the observation that the range of K+ concentrations in tears (ca 15–30mM) is high and Ca2+ and Mg2+ concentrations (ca 0.4–0.8 and 0.5–1.1mM) is low, relative to serum. The relative permeability coefficients of lenses and membranes were consistent (i.e. NaCl <KCl » CaCl2) ranging between 141.2×10−7: 148.2×10−7: 98.2×10−7 cm2/s (±5% for 90% acrylamide based hydrogel) and 2.8×10−7:3.2×10−7:0.7×10−7 cm2/s (±5% for 40% HEMA hydrogel). Conclusions: Ion chromatography enables tear electrolytes to be accurately monitored in 5 l samples. This, coupled with tear envelope sampling, provides a means of correlating clinical signs and symptoms with post-lens electrolyte concentrations and the ion permeability coefficients of individual lenses. Anisa Mahomed completed an MEng in Chemical Engineering and then obtained her PhD from the Biomaterials Research Group at Aston University. Her thesis discussed the aspects of the fabrication of novel hydrogels for dermal and ocular applications. She is currently a postdoctoral researcher and her interests include investigating factors that affect the uptake, release and transport of various species from hydrogels and developing analytical techniques to enable the understanding of clinical adverse events related to the use multipurpose solutions.

Non-invasive estimation of hydration status changes through tear fluid osmolarity during exercise and post-exercise rehydration

To determine if tear fluid osmolarity (Tosm) can track changes in hydration status during exercise and post-exercise rehydration. Nineteen male athletes (18-37 years, 74.6 ± 7.9 kg) completed two randomized, counterbalanced trials; cycling (~95 min) with water intake to replace fluid losses or water restriction to progressively dehydrate to 3 % body mass loss (BML). After exercise, subjects drank water to maintain body mass (water intake trials) or progressively rehydrate to pre-exercise body mass (water restriction trials) over a 90-min recovery period. Plasma osmolality (Posm) and Tosm measurements (mean of right and left eyes) were taken pre-exercise, during rest periods between exercise bouts corresponding to 1, 2, and 3 % BML, and rehydration at 2, 1, and 0 % BML. During exercise mean (± SD) Tosm was significantly higher in water restriction vs. water intake trials at 1 % BML (299 ± 9 vs. 293 ± 9 mmol/L), 2 % BML (301 ± 9 vs. 294 ± 9 mmol/L), and 3 % BML (302 ± 9 vs. 292 ± 8 mmol/L). Mean Tosm progressively decreased during post-exercise rehydration and was not different between trials at 1 % BML (291 ± 8 vs. 290 ± 7 mmol/L) and 0 % BML (288 ± 7 vs. 289 ± 8 mmol/L). Mean Tosm tracked changes in hydration status similar to that of mean Posm; however, the individual responses in Tosm to water restriction and water intake was considerably more variable than that of Posm. Tosm is a valid indicator of changes in hydration status when looking at the group mean; however, large differences among subjects in the Tosm response to hydration changes limit its validity for individual recommendations.

The Effects of Hemodialysis on Tear Osmolarity.

Aim. To determine the effects of hemodialysis (HD) on tear osmolarity and to define the blood biochemical tests correlating with tear osmolarity among patients with end stage renal disease (ESRD). Material-Method. Tear osmolarity of ESRD patients before and after the hemodialysis program was determined as well as the blood biochemical data including glucose, sodium, potassium, calcium, urea, and creatinine levels. Results. Totally 43 eyes of 43 patients (20 females and 23 males) with a mean age of 53.98 ± 18.06 years were included in the study. Tear osmolarity of patients was statistically significantly decreased after hemodialysis (314.06 ± 17.77 versus 301.88 ± 15.22 mOsm/L, p = 0.0001). In correlation analysis, pre-HD tear osmolarity was negatively correlated with pre-HD blood creatinine level (r = −0.366, p = 0.016). Post-HD tear osmolarity was statistically significantly correlated with the post-HD glucose levels (r = 0.305 p = 0.047). Tear osmolarity alteration by HD was negatively correlated with creatinine alteration, body weight alteration, and ultrafiltration (r = −0.426, p = 0.004; r = −0.365, p = 0.016; and r = −0.320, p = 0.036, resp.). There was no correlation between tear osmolarity and Kt/V and URR values. Conclusion. HD effectively decreases tear osmolarity to normal values and corrects the volume and composition of the ocular fluid transiently. Tear osmolarity alteration induced by HD is correlated with body weight changes, creatinine alterations, and ultrafiltration.

The Effect of Topical Cyclosporine 0.05% on Tear Osmolarity for Dry Eye Syndrome

Purpose: To evaluate the effect of topical cyclosporine 0.05% (Restasis; Allergan, Irving, CA, USA) on tear osmolarity in patients with dry eye disease. Methods: The present study was a single-center, randomized, prospective, and longitudinal trial. Patients who had been using artificial tears to treat dry eye disease were prescribed cyclosporine 0.05% and evaluated using tear osmolarity, tear break-up time, ocular surface staining score, Schirmer test, and the Ocular Surface Disease Index for symptomatic improvement. Clinical measurements of commonly used objective tests were performed at baseline and after 1, 3, and 6 months. Results: At the end of the study, patients demonstrated statistically significant improvement in tear break-up time (6.26 ± 1.26 sec at 3 months vs. 4.41 ± 1.63 sec at baseline, p = 0.022) and OSDI (34.98 ± 20.19 at 3 months vs. 45.02 ± 22.38 at baseline, p = 0.032) only at 3 months. Other measures such as Schirmer test, ocular surface grade, and tear osmolarity also showed improvement. However, the differences were not significant. Conclusions: Over a 6-month period, topical cyclosporine 0.05% showed beneficial effects on symptoms and other commonly used signs of dry eye disease for 3 months; however, the tear osmolarity values were not significantly improved. J Korean Ophthalmol Soc 2015;56(2):174-179

Tear Film Osmolarity in Diagnosis of Dry Eye Syndrome

Dry eye disease (DED) is a multifactorial disease which is characterized by the symptoms including burning, dryness, itching, pain, foreign body sensation and watering eyes. As causative mechanisms, the tear hyperosmolarity and tear film instability may initiate the dry eye. Increased tear osmolarity and ocular surface inflammation have a key role in the pathogenesis of DED. Tear osmolarity has been an exciting issue as in the diagnosis and management of DED. Herein, we discussed the role of tear osmolarity in the diagnosis procedures of DED. Keywords: Dry Eye Syndrome, Tear Film Osmolarity DOI: 10.12973/ejms.2014.124p

Tear osmolarity in ocular graft-versus-host disease.

The aim of this study was to evaluate tear osmolarity in patients with chronic graft-versus-host disease (cGVHD) with ocular involvement. In this observational cross-sectional study of 56 patients with ocular cGVHD referred to the tertiary-care Ocular Immunology and Uveitis Service at the San Raffaele Scientific Institute, Milan, from May 2010 to November 2013, we evaluated the following clinical parameters: Ocular Surface Disease Index (OSDI) symptoms questionnaire, tear osmolarity, Schirmer test, tear film break-up time (TBUT), corneal and conjunctival staining. All patients developed systemic GVHD after undergoing allogeneic hematologic stem cell transplantation. Mean osmolarity was 314.0 ± 22.1 mOsm/L, mean OSDI score was 26.4 ± 21.2, mean TBUT was 6.50 ± 4.75 seconds, and mean Schirmer test value was 3.8 ± 3.3 mm. Tear osmolarity significantly inversely correlated with TBUT (r = 0.681; P < 0.001). Statistically significant inverse correlation was present with the Schirmer test (r = 0.203; P < 0.001), and positive correlation with the OSDI score (r = 0.188; P < 0.001), but both with low correlation strength. Osmolarity was statistically different in the subgroups according to the Oxford corneal staining scale (P = 0.0006) and to the van Bijsterveld conjunctival staining score (P = 0.006). Tear osmolarity increased in patients with ocular cGVHD, significantly correlated with TBUT and, to a lesser extent, with the Schirmer test value and OSDI. These results emphasize the role of aqueous-deficient and evaporative dry eye disease in patients with cGVHD after undergoing allogeneic hematologic stem cell transplantation. Tear osmolarity may be considered a useful test in diagnostic assessment of dry eye disease associated with cGVHD.

Correlation between tear osmolarity and tear meniscus.

To examine the relationship between tear meniscus height (TMH) and subjective meniscus grading (subjective tear meniscus [TM]) with tear osmolarity. Tear osmolarity measurements (using TearLab) and digital images of the TM were obtained in 177 consecutive patients undergoing an eye examination at our optometry clinic (Universidad de Santiago de Compostela, Spain) who fulfilled the study's inclusion criteria. Participants were also administered the McMonnies and Ocular Surface Disease Index questionnaires for the detection of dry eye disease. The lower TM was videotaped by a digital camera attached to a slit lamp in its central portion without fluorescein instillation. After the study, a masked observer extracted an image from each video and measured the TMH using open source software (NIH ImageJ). Subsequently, the masked observer subjectively graded the appearance of each meniscus. For statistical analysis, subjects were stratified by age and by dry eye symptoms as indicated by their scores in the two questionnaires. In the whole study population, a significant relationship was observed between osmolarity and TMH (r = -0.41, p < 0.001) and osmolarity and subjective TM (r = 0.35, p < 0.001). A cluster analysis revealed similar correlations when subjects were stratified by age or dry eye symptoms, these correlations being more pronounced in older and more symptomatic subjects. Objective TMH measurements and subjective meniscus quality were also correlated (r = -0.75, p < 0.001). Osmolarity and both objective TMH measurements and subjective interpretation of the meniscus showed high correlation, especially in older symptomatic subjects.

Tear osmolarity and tear film parameters in patients with unilateral pterygium.

The aim of this study was to evaluate the differences in tear osmolarity and tear film parameters between pterygium-affected and healthy fellow eyes. The study enrolled 65 patients with unilateral pterygium. Tear osmolarity, tear film break-up time (TBUT), Schirmer I test measurements, fluorescein corneal staining, and conjunctival redness were evaluated. The results were compared between pterygium-affected eyes and healthy fellow eyes of the same patient (controls). The pterygium thickness was measured using optical coherence tomography. We also evaluated the relationship between pterygium thickness and tear osmolarity and between TBUT and Schirmer I test results in eyes with pterygium. The mean tear osmolarity was 307 mOsm/L in pterygium-affected eyes and 294 mOsm/L in control eyes. The mean values of TBUT, Schirmer I test, corneal staining, and conjunctival redness scores were 10.3 ± 3.4 seconds, 14.8 ± 9.2 mm, 1.2 ± 1.1, and 0.9 ± 0.9 in the pterygium group, whereas the mean values were 12.3 ± 4.4 seconds, 16.2 ± 7.2 mm, 0.4 ± 0.8, and 0.4 ± 0.7 in the control group, respectively. Eyes with pterygium had significantly higher tear osmolarity levels, corneal staining, and conjunctival redness scores; and lower tear film TBUT and Schirmer I test values than eyes without pterygium (Wilcoxon signed rank test, P < 0.05). There was no significant correlation between pterygium thickness versus tear osmolarity, TBUT, and Schirmer I test values in eyes with pterygium (r = 0.159, 0.738, 0.321, respectively; P > 0.05). This study showed that pterygium is associated with tear hyperosmolarity and abnormal tear film function.

Tear Osmolarity and Tear Function Changes in Patients with Acromegaly

Purpose: Since acromegaly is a disease with various systemic complications, it may also have ophthalmologic consequences. The aim of the current study was to compare the tear osmolarity and tear function changes in patients with acromegaly with those in healthy controls. Design: Prospective, cross-sectional study. Materials and methods: Fifty-nine consecutive patients with acromegaly and 62 age and gender matched healthy volunteers were enrolled in the study. Tear osmolarity measurement with TearLab Osmolarity System (Tearlab, San Diego, CA), tear film break-up time (TBUT) assessment, and the Schirmer test without anesthesia were performed in the same order in each group. Growth hormone (GH) and insulin like growth factor-1 (IGF1) levels were also determined in the study group. Results: The mean TBUT was lower in acromegalic patients (9.1 ± 3.6 seconds) than in healthy controls (10.7 ± 2.9 s) (p = 0.009). The difference between the two groups in tear osmolarity and Schirmer test results (p = 0.08 and p = 0.9, respectively) was not statistically different. Conclusions: Acromegaly may a cause a decrease in TBUT in the affected patient. Preservation of normal tear osmolarity and normal Schirmer test results suggests that this might be due to effects on the meibomian glands.

Diagnosis of X-Linked Hypohidrotic Ectodermal Dysplasia by Meibography and Infrared Thermography of the Eye

Purpose: X-linked hypohidrotic ectodermal dysplasia (XLHED) is the most common form of ectodermal dysplasia. Clinical characteristics include meibomian gland disorder and the resulting hyperevaporative dry eye. In this study, we evaluated meibography and ocular infrared thermography as novel methods to diagnose XLHED. Methods: Eight infants, 12 boys and 14 male adults with XLHED and 12 healthy control subjects were subjected to a panel of tests including the ocular surface disease index (OSDI), meibography and infrared thermography, non-invasive measurement of tear film break-up time (NIBUT) and osmolarity, Schirmer’s test, lissamine green staining and fluorescein staining. Sensitivity and specificity were determined for single tests and selected test combinations. Results: Meibography had 100% sensitivity and specificity for identifying XLHED. Infrared thermography, a completely non-invasive procedure, revealed a typical pattern for male subjects with XLHED. It was, however, less sensitive (86% for adults and 67% for children) than meibography or a combination of established routine tests. In adults, OSDI and NIBUT were the best single routine tests (sensitivity of 86% and 71%, respectively), whereas increased tear osmolarity appeared as a rather unspecific ophthalmic symptom. In children, NIBUT was the most convincing routine test (sensitivity of 91%). Conclusions: Meibography is the most reliable ophthalmic examination to establish a clinical diagnosis in individuals with suspected hypohidrotic ectodermal dysplasia, even before genetic test results are available. Tear film tests and ocular surface staining are less sensitive in children, but very helpful for estimating the severity of ocular surface disease in individuals with known XLHED.

The heritability of dry eye disease in a female twin cohort.

We estimated the relative importance of genes and environment in dry eye disease (DED) using a classic twin study. A large sample of 3930 female monozygotic and dizygotic twins from the UK Adult Twin Registry (TwinsUK) was questioned about the presence of a DED diagnosis and about DED symptoms in the preceding 3 months. In addition, a subset of 606 twins was examined for several dry eye signs. Genetic and environmental effects were estimated using maximum likelihood structural equation modeling. All DED outcome variables showed higher correlation in monozygotic twin pairs than in dizygotic twin pairs, suggesting genes have a contributory role in DED. The DED symptoms showed a heritability of 29% (95% confidence interval [CI], 18%-40%). A clinician's diagnosis of DED with concurrent use of artificial tears showed a heritability of 41% (95% CI, 26%-56%). Estimates of the heritability of DED signs were 25% (95% CI, 7%-42%) for interblink interval, 58% (95% CI, 43%-70%) for Schirmer value, 40% (95% CI, 25%-53%) for tear osmolarity, and 78% (95% CI, 59%-90%) for the presence of blepharitis. The unique environment explained the remainder of the variance. We found no significant heritability for tear breakup time. Genetic factors contribute moderately to the diagnosis, symptoms, and the signs of DED. Compared to other ocular phenotypes, the lower heritability might reflect some of the difficulties in objective phenotyping of DED in a population-based sample. However, future genetic studies are now justified and may help in unraveling the pathophysiology of DED.

Tear Osmolarity - Current Perspectives in Cornea Practice

Tear Osmolarity - Current Perspectives in Cornea Practice

Rethinking clinical significance of tear osmolarity measurement for dry eye diagnosis and therapeutic efficacy evaluation

Increased tear osmolarity is one of the core mechanisms of dry eye and has been considered as an important diagnostic criterion, if not"gold standard", of dry eye. However, recent studies showed the limitations of tear osmolarity measurement not only in the diagnosis, but also in the therapeutic efficacy evaluation of dry eye. The clinical significance of tear osmolarity measurement has become a hot topic of argument. Herein, we review the publications on this topic and try to find the underlying causes of such argument.

Changes of inflammatory cytokines and tear osmolarity in systemic sclerosis after treatment with liposomes sprayed

AbstractPurpose To investigate the effect of treatment with a liposomal spray solution in patients with systemic sclerosis (SSc) and severe dry eye by measuring the levels of inflammatory cytokines and tear osmolarity.Methods Twenty‐two subjects (12M, 10F) aged 45.1+/‐7.1 years participated in this prospective, randomised, double‐masked investigation. DES was identified in patients with SSc according to the classification of Dry Eye Disease of International Dry Eye Workshop (2007) and tear osmolarity values (TearLab system) according to recommendations of the manufacturer with a cutoff value of 308 mOsm/L (3). Liposomal spray (nebulized, two sprays each, on the eyelids, 3 times per day for 3 weeks) with vitamin A and E was applied to one eye, and an equal volume of saline spray (control) applied to the contralateral eye. Non‐invasive tear film stability (NIBUT), osmolarity and inflammatory cytokines (IL‐1β, IL6, TNF‐α,IFN‐γ) were evaluated at baseline, and at 5, 10, 15 days after spray solution application.Results A highly significant reduction (p&lt;0.01‐0.001) was detected in the inflammatory cytokine levels and osmolarity in tears of eye treated with the spray liposomes solution in comparison with fellow eye treated with sprayed saline solution. There were significant differences among the 2 eyes concerning tear osmolarity (p &lt; 0.001) and TBUT (p &lt; 0.05) scores.Conclusion This study showed the ability of liposomal spray application to modify the pro‐inflammatory cytokine profile and to increase stability characteristics of the pre‐ocular tear film in severe dry eye of SSc patients.This effect could be due to the anti‐inflammatory mechanism of the vitamins and also to the barrier effect of liposomes.

Change in tear film characteristics in visual display terminal users.

To evaluate changes in symptoms and tear film characteristics in young computer users. Fifty-one computer users and 26 controls were evaluated at the beginning and the end of the working day. Subjects with ocular or systemic disease, history of ocular surgery, use of contact lenses or glasses with antireflective surfaces, and use of topical or systemic medications were excluded from the study. Computer use duration, Ocular Surface Disease Index (OSDI) questionnaire, tear osmolarity, Schirmer test, tear break-up time (TBUT), and ocular surface vital dye staining were performed prevocationally and postvocationally. The mean age was 31.2 ± 6.3 years in computer users and 33.7 ± 5.8 in controls. The mean reported computer use was 6.9 ± 2.7 hours/day in computer users and 0.4 ± 0.5 hours/day in controls. The mean prevocational and postvocational values in computer users for OSDI, osmolarity, TBUT, and Schirmer test were 23.2 ± 16.6 and 27.0 ± 17.6, 306.6 ± 14.9 and 311.0 ± 12.5 mOsm/L, 13.9 ± 4.0 and 13.2 ± 3.8 seconds, 22.7 ± 11.8 and 20.6 ± 12.5 mm, respectively. The vocational change was significant for all parameters in the computer user group but not in the control group. The osmolarity-based dry eye diagnosis was 27.4% in the computer users while it was 15.4% in the control group. Oxford score was only grade 1 in 5.9% of visual display terminal users and did not change at the end of the day. Both symptoms and signs of dry eye increased significantly with computer use. Approximately 1 of every 3-4 computer users was found to have dry eye with higher tear osmolarity values.

Evaluation of Tearing in Oculoplastics Assisted by Tear Osmolarity Measurement

Purpose: To determine the tear osmolarity in patients with tearing secondary to dry eye and other pathologies, and to determine the prevalence of dry eye disease among patients with tearing in an oculoplastics setting.Methods: 108 eyes of 54 patients with a chief complaint of tearing were prospectively recruited. Subjects were excluded if they used eye drops or contact lenses within 2 hours of assessment, had a history of refractive surgery, an active ocular allergy, or evidence of a systemic disease which affects tear production. A full medical and ocular history was taken with a complete eye exam pertinent to dry eye. Tear osmolarity was measured using the TearLab device. A clinical diagnosis of dry eye was made based on findings, without reference to tear osmolarity.Results: Among 86 eyes symptomatic for tearing, 32 eyes had dry eye disease (37%). Patients with dry eye had a significantly higher median tear osmolarity compared to that in patients with other diagnoses (308 mOsm/L vs. 294 mOsm/L, p < 0.0001). At a cut-off of 308 mOsm/L, tear osmolarity resulted in a sensitivity of 50% and a specificity of 88% for the diagnosis of dry eye.Conclusions: A significant proportion of patients with tearing in an oculoplastics practice had dry eye disease. The high specificity of tear osmolarity may render it a useful tool to rule in dry eye disease and may assist the oculoplastic surgeon in more accurately determining the cause of tearing.

Effect of religious fasting on tear osmolarity and ocular surface.

To evaluate the effects of religious fasting on tear secretion, tear osmolarity, corneal topography, and ocular aberrations. This prospective controlled study comprised 29 eyes of 29 healthy men. Before ophthalmologic examination, all subjects underwent corneal topography by a placido disc corneal topography and aberrometry device (OPD Scan II). Tear osmolarity was measured using OcuSense TearLab osmometer. Ocular surface disease index (OSDI) scores, tear break-up time (BUT), Schirmer I test, and lissamine green staining were evaluated. The measurements taken before and during Ramadan at the same hours between 4.00 and 5.00 PM were compared using paired sample t test, and a P value less than 0.05 was accepted as statistically significant. The mean age of the study group was 27.8 ± 5.9 years (range, 20-47 years). The mean tear osmolarity values were measured as 285.6 ± 8.2 mOsm/L and 293.3 ± 16.0 mOsm/L, whereas the mean Schirmer I values were 14.8 ± 6.0 mm and 10.6 ± 5.3 mm in nonfasting and fasting periods, respectively. Tear osmolarity, OSDI, and Oxford grading scores significantly increased (P=0.02, P=0.002, P=0.003, respectively), whereas Schirmer I values and intraocular pressure decreased (both, P<0.001) during the fasting period compared with the nonfasting period. There were no significant differences in tear BUT, keratometry values, and corneal aberration measurements between nonfasting and fasting periods (P>0.05, for all). Fasting significantly decreases tear production and increases tear osmolarity; however, it does not deteriorate corneal topographic parameters and ocular aberrations in healthy subjects.