[A preliminary study on optical coherence tomography of the lacrimal punctum in normal adults]

Objective: To study the imaging characteristics and accumulate data of optical coherence tomography (OCT) of the lacrimal punctum in normal adults. Methods: From September to November 2018, 59 healthy adults (90 eyes) with normal lacrimal punctum structure were enrolled in this cross-sectional study conducted at the Lacrimal Center of Ophthalmology, Third Medical Center of PLA General Hospital, including 21 males (34 eyes) and 38 females (56 eyes), aged 18-65 years. All the subjects were examined by slit lamp microscopy to measure the maximum transverse diameter. OCT was performed to observe the inferior lacrimal punctum, including the external punctal diameter, the punctal diameter at 100 μm and 200 μm depth. The difference in the diameter of different parts of the punctum was analyzed. Independent sample t test and single factor analysis of variance were used for statistical analysis. Results: In normal adults, the maximum transverse diameter under a slit lamp was (545.6±149.3) μm, the external punctal diameter on OCT images was (548.4±130.5) μm, and the punctal width at 100 μm and 200 μm depth on OCT images was (262.8±120.8) μm and (179.2±110.0) μm, respectively. There was no significant difference between the maximum transverse diameter of the punctum under a slit lamp microscope and the OCT outer diameter of the punctum (t=0.133, P=0.894). There were significant differences between the diameter of the lacrimal punctum in the different scanning sites of the OCT (F=213.237, P<0.01). There was significant difference between the punctal width at 100 μm and the external punctal diameter on OCT images (t=15.229, P<0.01). There was significant difference between the punctal width at 200 μm and the external punctal diameter on OCT images (t=20.517, P<0.01). There was significant difference between the punctal width at 100 μm and 200 μm depth on OCT images (t=4.855, P<0.01). Conclusion: The width of different parts of the lacrimal punctum in healthy adults is different on OCT images, and the punctal width at 200 μm depth is the narrowest. (Chin J Ophthalmol, 2019, 55: 695-699).