Measurement of lacrimal punctum using spectralis domain anterior optical coherence tomography

Abstract

Purpose: Anterior segment optical coherence tomography (AS-OCT) was used to image the lacrimal punctum and establish normal punctal parameters including the tear volume inside the punctum.

Methods: This study included totally 67 eyes from 38 normal subjects. Punctal parameters and tear meniscus height (TMH) were measured using spectralis OCT anterior-segment scans. Outer punctal diameter (OPD), punctal depth, tear well diameter (TWD), tear well depth, punctal reserve (PR) and lower eyelid TMH were assessed. Authors defined a 'tear well' as a pool of standing tears in the punctum. Punctal reserve was defined as the difference between punctal depth and tear well depth.

Results: Outer punctal diameter was 614.6 ± 195.6 μm, the punctal depth was 545.8 ± 270.1 μm, TWD was 229.9 ± 133.8 μm, the tear well depth was 434.9 ± 247.8 μm, the PR was 110.9 ± 72.9 μm, the PR ratio was 0.20 ± 0.17, and the TMH was 222.9 ± 88.8 μm. The punctal depth decreased significantly according to the patient's age (correlation coefficient = -0.352, respectively).

Conclusion: AS-OCT is useful for improving anatomical understanding of the lacrimal punctal structure. Quantitative punctum and tear well measurements were correlated with TMH.

Keywords: lacrimal punctum; normal population; optical coherence tomography; tear dynamics.