The Langmuir Technique Applied to the Study of Natural Tears

As a new proposal, natural tears collected from the Schirmer strips were studied using surface pressure-area, π-A, isotherms obtained with the Langmuir technique. Parameters such as limit surface pressure, π limit , elastic modulus at the maximum, C S −1 max , and surface pressure at the maximum, π max , were correlated with clinical tests, such as the Schirmer (SCH) and the tear film breakup-time (TFBUT) tests. The analysis from the chi-square test indicates dependence between the SCH test and the type of isotherms with a value of P