Introduction: Lacrimal punctum is the entry point for tears to the nasolacrimal duct. In the literature there are few studies on the punctum, due to the lack of consensus regarding the imaging modalities for the proximal lacrimal system. There are currently no routinely used imaging modalities for the proximal lacrimal system.
Aim: The aim of this article is to assess the proximal lacrimal system using a novel non-contact method with the use of anterior segment optical coherence tomography.
Materials and Methods: This study included 25 right eyes of 25 healthy volunteers. Optical coherence tomography images of the right lower lacrimal puncta were obtained by two operators using SD OCT 3D OCT-2000 FA Plus (Topcon Corporation, Japan) and software version 8.11. The measurements were repeated after 7 days. The inner diameters of the canaliculus and tear meniscus height were measured. IBM SPSS v23 was used for statistical analysis.
Results: The mean age of subjects was 24 ± 2.4 years. The study included 10 males and 15 females. The mean punctal diameters at Visit 1 and Visit 2 were 179.08 ± 76.97 µ and 179.64 ± 76.37 µ for investigator 1 (experienced), and 204.72 ± 106.98 µ and 192.32 ± 91.52 µ for the second investigator (inexperienced), respectively. In 20 patients the tear meniscus height in the punctum was measured. The Wilcoxon signed-rank test showed no statistically significant difference between the values of the two investigators (p = 0.106). Linear regression analysis demonstrated excellent correlation between the investigators (p = .000, r = 0.834). Levene’s test of homogeneity showed similar measurement variance between observers (p = 0.424, F = 0.643).
Conclusion: Anterior segment optical coherence tomography can be successfully used to visualize the structures of the proximal lacrimal system and provide accurate measurement of the inner diameter of the canaliculus and tear meniscus height in healthy subjects. The method demonstrates excellent repeatability, which does not depend on investigator experience. It could be implemented successfully in future diagnostics of different lacrimal pathologies for objective assessment by imaging technology.
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