[Evaluation of tear meniscus volume using the DR-1 tear specular scope].

PURPOSE: To investigate whether images obtained using DR-1, a tear specular microscope, can be applied to the evaluation of tear meniscus volume. METHODS: Of 94 eyes of 47 subjects examined, 66 eyes of 33 subjects were diagnosed with definite, suspected or absence of dry eye using the 2006 diagnostic criteria. Tear meniscus height values found using DR-1 meniscus height (DRMH, mm), slit lamp meniscus height (SLMH, low/medium/high), and fluorescein meniscus height (FLMH, mm) were compared. The reproducibility, sensitivity and specificity of DRMH values with regard to dry eye diagnosis were investigated. Changes in DRMH after insertion of lacrimal plugs and during soft contact lens (SCL) wear were also examined. RESULTS: DRMH was significantly correlated with SLMH (r = 0.737, Spearman rank correlation coefficient) and FLMH (r = 0.06, Bland-Altman analysis). DRMH values (mm) in the normal (0.29 +/- 0.05), suspected dry eye (0.19 +/- 0.07), and definitely dry eye groups (0.17 +/- 0.06) were significantly different (p < 0.001), and showed good reproducibility. At a cut-off value of 0.22 mm, the sensitivity of dry eye diagnosis was 84.1% and specificity was 90.9%. DRMH increased significantly after insertion of lacrimal plugs (p < 0.0001) and decreased significantly during SCL use (before vs. 60 minutes after SCL insertion, p < 0.05, before vs. 120 minutes after insertion, p < 0.001). CONCLUSION: DR-1 and specialized analysis software make simple and non-invasive evaluation of tear meniscus volume possible.