Purpose:
To evaluate the accuracy of optical coherence tomography (OCT) meniscometry and its efficacy as a marker of epiphora in primary nasolacrimal duct obstruction.
Methods:
Anterior segment OCT imaging was performed in both eyes of 39 subjects. Cases (n=29) were suffering from unilateral severe tearing (Munk grade 3 or more) and lacrimal duct obstruction, explored by irrigation. Age and gender-matched controls (n=10) did not refer any tearing complaint (Munk grade 0) or symthom of past lacrimal disfunction. All images were taken under controlled room temperature and humidity using anterior segment 3D-OCT-1000 (Topcon, Inc., Japan). Fastmap Software was used to measure the lower tear meniscus high (TMH), and depth (TMD) (Figure 2). Every measure was taken independently by two different subjects.
Results:
A Spearman's correlation between TMH and TMD of Rho 0,85-0,95 was found respectively in both groups. Independent sample tests show significant differences in TMH and TMD between fellow eyes in the case group, with an average increase in 363um (TMH) and 224,7um (TMD) compared with the control group (CI: 95%). However, no significant differences in TMD or TMD were found between fellow eyes in the control group p <0,001. Bland-Altman plots show a strong agreement between observers Figure1.
Conclusions:
As might be predicted, there is a strong correlation in both measures between fellow eyes in asymptomatic subjects. In the case group, the average increase in TMH and TMD of the tearing eye compared with the fellow eye, implies a strong possitive correlation between both parameters and the clinical symthoms. OCT assited meniscometry has shown to be a reproducible and non invasive tool to evaluate the competence of the lacrimal drainage system under fisiological conditions.
Keywords: imaging/image analysis: clinical • anterior segment • lacrimal gland