Comparison of Ocular Surface Disease Index and Tear Osmolarity as Markers of Ocular Surface Dysfunction in Video Terminal Display Workers

Purpose To compare the ocular surface disease index (OSDI) questionnaire and tear osmolarity, to screen ocular surface alterations in video display terminal (VDT) users. Design Cross-sectional study. Methods Sixty-four VDT workers were screened for ocular surface alterations using OSDI and tear osmolarity. Furthermore, tear film break-up time (TBUT), fluorescein corneal stain and assessment for meibomian glands dysfunction (MGD) were carried out. The alteration of two or more among these parameters was considered a sign of ocular surface dysfunction. Data for the statistical analysis were obtained from the eyes with the worst tear osmolarity score. Main outcome measures were: OSDI and tear osmolarity. For the statistical analysis the receiver operating characteristic (ROC) curves and Spearman’s correlation coefficient were used. A p<0.05 was considered statistically significant. Results The area under the ROC curve (AUC) for tear osmolarity (ranging from 0.71 to 0.86) showed, for all the classification variables considered, statistically significantly higher values than those obtained with OSDI (ranging from 0.51 to 0.58) (p<0.01). Furthermore, tear osmolarity showed a direct correlation with corneal stain and ocular surface dysfunction and an inverse correlation for TBUT. No correlation was found between OSDI and the parameters considered. Conclusions Tear osmolarity can be considered a more reliable test than OSDI, when screening VDT users for possible ocular surface alterations.