Scaling the punctum and canaliculus in patients undergoing punctoplasty surgery: A prospective cohort study

Optical Coherence Tomography (OCT) is a safe and non-invasive method of high-resolution cross-sectional imaging of tissue microstructures using infrared radiation. This study investigates how the appearance of the punctum and proximal canaliculus differs pre- and post-operatively in patients undergoing punctoplasty surgery. Patients with symptomatic punctal stenosis warranting punctoplasty surgery were prospectively invited to enrol from a single centre. Spectral OCT images of the lower punctae were captured with a Topcon 3D OCT 2000 machine pre- and post-operatively (at their follow-up appointment). Measurements were made of the maximal punctal diameter, canalicular diameter and canalicular depth. Pre- and post-operative measurements were compared using a paired t-test. Twenty-three punctae of 18 patients with punctal stenosis were included in the study. They were 10 males and 8 females with a median age 71.0 (SD 12.1). Mean canalicular cross-sectional area was 56.9 × 10-3 mm² pre-operatively and 267.2 × 10-3 mm² post-operatively, showing a statistically significant increase (p = 0.0004). There was an increase in both mean canalicular width (0.253 to 0.524mm (p = 0.0001)) and depth (0.433 to 0.852mm (p = 0.0001)) from pre- to post-operatively. There was a significant improvement in symptoms from pre- to post-operatively, as measured subjectively by the Lac-Q questionnaire (p = 0.021). This study describes the change in the appearance of the punctum and proximal canaliculus in patients undergoing punctoplasty operations, by using spectral OCT to capture in vivo high-resolution images. It demonstrates that punctal OCT can be successfully applied to quantify the morphological changes of the punctum and canaliculus pre- and post-punctoplasty.