Tear Dynamics and Corneal Confocal Microscopy of Subjects with Mild Self-Reported Office Dry Eye

Abstract

To investigate changes in tear dynamics and corneal microstructure in mild self-reported office dry eye. Prospective laboratory investigation. Twenty healthy office workers, 20 office workers with mild self-reported dry eye, and 20 office workers with moderate to severe dry eye as determined by the Ocular Surface Disease Index (OSDI). Real-time anterior segment optical coherence tomography was used to obtain upper (UTMV), lower (LTMV), tear meniscus volumes. The total tear meniscus volume (TTMV) was the sum of the UTMV and LTMV. This was followed by measurement of noninvasive tear breakup time (NITBUT), fluorescein tear breakup time (FTBUT), fluorescein staining, Schirmer I test, and in vivo confocal microscopy of cornea. Upper tear meniscus volume, LTMV, TTMV, NITBUT, fluorescein tear FTBUT, fluorescein staining, Schirmer I test, and in vivo confocal microscopy of cornea. There were no significant differences in UTMV and LTMV between the control and mild self-reported dry eye groups (P>0.05). These values in the moderate to severe dry eye group were significantly lower than those in the control and mild dry eye groups (P<0.01). Both mild and moderate to severe office dry eye groups had decreased NITBUT (P<0.05 each) and FTBUT (P<0.01 each) compared with controls. On the basis of receiver operating characteristic curves, the cutoff value for abnormal FTBUT was 3.3 seconds, yielding good diagnostic accuracy with a sensitivity of 0.75 and specificity of 0.80. For NITBUT, when the cutoff time was 9.7 seconds, the sensitivity was 0.90 and specificity was 0.50. The moderate to severe office dry eye group had decreased Schirmer I test values and increased subbasal nerve tortuosity compared with the mild office dry eye and control groups (P<0.05 each). Both the mild dry eye and moderate to severe dry eye groups had decreased cell densities in superficial, intermediate, and basal epithelial layers compared with the controls (P<0.05 each). Although the quantity of tears in patients with mild self-reported office dry eye was not decreased, ocular surface damage was present.