Tear Meniscus Evaluation By Optical Coherence Tomography And Its Application In Diagnosis Of Dry Eye.

[OBJECTIVE] To evaluate the applicability of OCT to the diagnosis of dry eye through measuring the height , depth and cross-area of tear meniscus .[METHODS] In addition to the Schirmer I Test ,Tear Break Up Time and Fluorescein Staining were used ,We tested the tear meniscus by OCT for 37 patients(37 eyes) with dry eye (aqueous tear deficiency) and for 34 (34 eyes) normal controls. Tear meniscus height, depth and cross-area were measured with an external program for both groups. Meanwhile ,the area under receive operating characteristic curve (ROC AUC) and intraclass correlation coefficient (ICC) were calculated.[RESULTS] Mean tear meniscus height, depth and cross-area was significantly lower(P<0.001) in patients with dry eye (mean±sd: 0.25±0.08mm,0.23±0.08 mm and 0.0283±0.0197 mm2) than in the control group (0.13±0.05 mm, 0.13±0.06 mm and 0.0103±0.0062 mm2).This demonstrated a significant difference between the two groups. There was a negative correlation between subjective symptoms and tear meniscus height (r=-0.54,P<0.001), high positive correlation between tear meniscus height and depth (r=0.92,P<0.001),and positive correlation between Schirmer test ,BUT and tear meniscus height. For the height, depth and cross-area of tear meniscus, the area under ROC curve was 0.921, 0.884 and 0.895;the ICC of intra-observer agreement of tears meniscus height measurement by OCT was 0.85.[CONCLUSION] Optical coherence tomography can be conveniently used to noninvasively visualize the tear meniscus. This method, with a high accuracy and repeatability, can be used to discriminate between patients with normal and dry eyes when measuring tear meniscus height, depth and cross-area.