Optical coherence tomography for measuring the tear film meniscus: correlation with schirmer test and tear-film breakup time.

PURPOSE

To compare tear meniscus height (TMH) and area (TMA) values obtained by optical coherence tomography (OCT) with the Schirmer test and tear-film break-up time (TBUT) values.

MATERIALS AND METHODS

In this prospective cross-sectional study, the right eyes of 300 consecutive patients were studied. All patients underwent routine ophthalmologic examination. Schirmer and TBUT measurements were taken, and tear-film OCT images were obtained. Using OCT, the TMH (i.e. the line connecting the intersection of the meniscus with the cornea and eyelid) and cross-sectional TMA were calculated. Patients were divided into Groups 1 (Schirmer values ≤5 mm) and 2 (Schirmer values >5 mm). Data were analyzed using SPSS 13.0 software. The Mann-Whitney U-test was used for the comparison of groups. Correlations between tear parameters were analyzed.

RESULTS

There were no significant differences in age, logMAR, or IOP values (p = 0.480, 0.077 and 0.146, respectively) between the two groups. Mean TBUTs were 5.1 ± 2.9 and 9.5 ± 4.2 s for Groups 1 and 2, respectively (p < 0.001). Mean TMHs were 237.9 ± 108.9 and 324.3 ± 158.9 μm for Groups 1 and 2, respectively (p < 0.001). Mean TMAs were significantly lower in Group 1 compared to Group 2 (p < 0.001; 0.027 ± 0.028 versus 0.055 ± 0.059 mm(2), respectively). Correlations between Schirmer values and TMH, and between Schirmer values and TMA, were significant (p = 0.001 and <0.001, respectively).

CONCLUSIONS

OCT values were significantly lower in patients with Schirmer values of <5 mm. Tear meniscus measurements obtained by OCT are reliable for establishing a diagnosis of dry eye.