Syfte: Denna studie fokuserar på att åskådliggöra för- och nackdelar med osmolaritetsmätning som diagnostiseringsmetod samt den roll tårfilmens osmolaritet har för ögontorrhet. Metod: En litteraturbaserad studie genomfördes där kunskap inom området sammanställdes till en mer lättöverskådlig text. Ett antal vetenskapliga artiklar valdes även ut för granskning och analys. Resultat: Arbetet visar att merparten av de studier som är gjorda inom området osmolaritetsmätning framhåller metoden som en av de bästa diagnostiseringsmetoder som finns när det kommer till fastställande och gradering av ögontorrhet. De färskaste studierna i detta arbete pekar dock på vissa brister med metoden så som fluktuerande mätresultat och rekommenderar att flera mätningar bör utföras vid varje mättillfälle och att ett snittvärde av mätningarna bör användas för att ge ett pålitligt resultat. Slutsats: Fler och större studier skulle behövas för att säkrare fastställa effektiviteten och tillförlitligheten hos osmolaritetsmätaren TearLab

Purpose: The purpose of this study was to investigate if there was a difference in the tear film’s osmolarity before and after drinking coffee. ' Method: All subjects in this study were asked to fill in a questionnaire to diagnose factors in their subjective symptoms, the questionnaire TERTC-DEQ. The subjects with a total graduated points of over 17 were not allowed to participate in the further measurements. In the study there was a total amount of 38 subjects, were 5 participated twice for both measurements, coffee and water. The measurements were done by TearLab to bring the the osmolarity values, of coffee and water, the before and after measurements, to be compared with each column. Each subject was measured before the drinks was served, 200 milliliters of water or 200 milliliters of coffee. 45 minutes after the first measurement, after the intake of one of the liquids, then the second measurement was occured with TearLab.  All of these values and measurements was later compared to each columns of coffee or water. Results: There was no significant difference between neither the coffee or water results (p>0,05). Though there was a little quotable difference between the before and after measurement values of coffee, but not significant. Conclusion: There was no significant difference related to coffe drinking and tear osmolarity. There is no contribution to the tear film’s osmolarity and it will not work as a factor into the dry eyes diagnosis.

Syfte: Syftet med studien var att utvärdera om det fanns någon variation av tårfilmens osmolariet, morgon och kväll hos personer utan symptom av torra ögon. Metod: Tårfilmens osmolaritet mättes på totalt 30 patienter, två gånger på en dag; morgon och kväll. Mätningarna utfördes med TearLabTM osmolarity system. Både höger och vänster öga mättes på varje patient. Samtliga deltagande ombads fylla i en symptomenkät vid namn TERTC-DEQ. Endast personer utan symptom på torra ögon tilläts delta i studien. Alltså personer med totalt  17 poäng på TERTC-DEQ. Resultat: Ingen statistisk signifikant skillnad kunde iakttas hos personernas osmolaritet mellan morgon och kväll (P > 0.05). Slutsats: I studien kunde ingen skillnad på osmolaritet i tårfilmen iakttas mellan morgon och kväll hos personer utan symptom på torra ögon. Därmed tros tårfunktionen hos dessa personer fungera korrekt. Tårfilmens osmolaritet upprätthåller rätt balans och förändras därför inte från morgon till kväll. / Aim: The aim of this study was to determine if there is an diurnal variation in tear osmolarity among healty non dry-eye subjects. Method: The osmolarity of the tearfilm was measured in a total of 30 subjects twice a day; morning and evening, using the TearLabTM osmolarity system. Measurements were performed on both right and left eye in all the subjects. All subjects were asked to fill in a symptom questionnaire named TERTC-DEQ and only those with a total score of  17 points were allowed to participate in the study. Subjects below this score had therefore no symptoms of dry eye. Results: There was no statistical significant difference between the subjects tear osmolarity comparing the morning and evening values (P>0,05). Conclusion: This study did not show any difference in the subjects tear osmolarity, comparing morning and evening measurements. None of the individuals had any symptoms of dry eye. Therefore it is believed that in subjects with no symptoms of dry eye, the tear osmolarity remains stable between morning and evening.

Dry eye is a complex, multi-factorial disease that results in a compromised tear film and ocular surface. Clinicians and researchers alike have historically relied on an individual’s symptoms to diagnose and manage the condition, due to a lack of reliable objective methods for quantifying disease presence and severity. Of late, parameters such as tear film osmolarity and tear meniscus height have shown promise as valid methods for enumerating characteristics of the tear film that may aid the diagnosis of dry eye. Two new technologies have recently been introduced that can measure said parameters. The TearLab™ is a novel handheld nano-osmometer capable of measuring tear film osmolarity on samples as small as 50 nL. The device uses electrical conductance to measure osmolarity, and the small sample requirements purportedly allows the device to minimally disturb the natural state of the tear film. The RTVue-100 is a spectral-, or Fourier-domain optical coherence tomographer that has the ability to generate high resolution, cross-sectional images of the tear meniscus, and subsequently measure tear meniscus height. As little is published on the use of these technologies to evaluate the tear film, a series of studies was completed to determine their performance in both a normal and dry eye population.

Dry eye is a complex, multi-factorial disease that results in a compromised tear film and ocular surface. Clinicians and researchers alike have historically relied on an individual’s symptoms to diagnose and manage the condition, due to a lack of reliable objective methods for quantifying disease presence and severity. Of late, parameters such as tear film osmolarity and tear meniscus height have shown promise as valid methods for enumerating characteristics of the tear film that may aid the diagnosis of dry eye. Two new technologies have recently been introduced that can measure said parameters. The TearLab™ is a novel handheld nano-osmometer capable of measuring tear film osmolarity on samples as small as 50 nL. The device uses electrical conductance to measure osmolarity, and the small sample requirements purportedly allows the device to minimally disturb the natural state of the tear film. The RTVue-100 is a spectral-, or Fourier-domain optical coherence tomographer that has the ability to generate high resolution, cross-sectional images of the tear meniscus, and subsequently measure tear meniscus height. As little is published on the use of these technologies to evaluate the tear film, a series of studies was completed to determine their performance in both a normal and dry eye population.