Correlation between tear osmolarity and the dry eye severity / 中华实验眼科杂志

ABSTRACT

Background There still is no a uniform diagnostic criteria for increasing population of dry eye.Studies showed that high tear osmotic pressure is one of causes of a variety of ocular surface discomfort,and the change of tear osmolality has been included in the definition of dry eye syndrome by Dry Eye World Study Group (DEWS) in 2007.It is very clinically significant to study the relationship of tear osmolality with dry eye.Objective This clinical trial was to study the correlation between tear osmolarity and dry eye severity based on Preferred Practice Pattern(PPP)of DEWS.Methods A descriptive study was performed.Fifty-four eyes of 54 patients with dry eye disease were asked to complete an evaluation of dry eye signs and symptoms questionnaire based on PPP.The ocular anterior segment was examined under the slit lamp biomicroscope.Cornealfluorescein staining,tear-film breakup time (BUT),Schirmer test Ⅰ (S Ⅰ t)without anesthesia were performed,and tear sample was collected for tear imageology and tear osmolarity admeasurement.The correlation between dry eye score with tear osmolarity was evaluated using Pearson linear correlation analysis.Written informed consent as obtained prior to any relevant medical procedure.Results The ratio of male and female patients was 1 2 in this study.The negative correlations were found between tear osmolarity with S Ⅰ t or BUT(r =-0.456,-0.699,P＜0.01),and significantly positive correlations were found between tear osmolarity with tear imaging examination,corneal fluorescein staining,conjunctival hyperemia or dry eye symptom score(r=0.545,0.686,0.691,0.803,P＜0.01).Conclusions As a diagnostic method,tear osmolarity can objectively reflects dry eye severity.It can be a biomarker in dry eye severity grade when combined with clinical symptom.