[Use of optical coherence tomography based lacrimal meniscometry in dacryology].

Unlabelled: Optical coherence tomography (OCT) based lacrimal meniscometry is currently the most accurate method used to determine dimensions of tear meniscus. According to related literature, the latter gets reliably reduced after treatment of nasolacrimal duct obstructions. However, the relationship between morphometric parameters of tear meniscus and the intensity of epiphora has not been established. Even an adequate study parameter has not been yet identified.

Aim: To investigate the significance of OCT based lacrimal meniscometry in determining the extent of insufficiency of lacrimal drainage.

Material And Methods: A total of 108 measurements of the lower tear meniscus were taken. Of them, 23 measurements were taken in healthy volunteers, who had no complaints of epiphora, 59 - in patients with epiphora of different intensity, and 26 - in patients after surgical intervention. Meniscometry was performed with RTVue-100-2 (Optovue, USA) optical coherence tomograph. The tear meniscus 'height', 'depth', and coefficient were evaluated. Munk's scores for epiphora were also collected. Spearman's correlation was applied to assess the morphometry results and Munk's scores. A separate analysis was performed for patients who were examined before and after dacryological treatment. Differences were evaluated with the Kruskal-Wallis H test.

Results: Statistically reliable differences were found between the meniscus 'height' and 'depth' values at different epiphora intensities (p<0.001 for both parameters; H=25.35 and 22.01, respectively), however, the meniscus coefficients showed no significant difference in these patients (p=0.8, H=1.57). Moreover, there was a highly reliable (p<0.001) medium strength direct correlation between the meniscus 'height' and 'depth' and the Munk's scores (R=0.46 and R=0,48, respectively), while the correlation between the meniscus coefficient and the Munk's scores appeared weak and lowly reliable (p=0.20, R=0.14).

Conclusion: Lower meniscus morphometry with 'depth' measurement is a comprehensive method to assess the state of lacrimal drainage system. However, it should not be used alone due to significant variations in morphometric parameters, particularly in patients with intensive epiphora.