AIM: To quantify the lacrimal punctum using anterior segment optical coherence tomography(AS-OCT)and analyze the correlation between the epiphora and primary punctal stenosis.

METHODS: A cross-sectional study. There were 43 healthy volunteers(57 eyes)and 44 patients(62 eyes)with primary lacrimal punctal stenosis and epiphora enrolled in the Lacrimal Center of the Third Medical Center of PLA General Hospital from September 2020 to January 2021. The inferior punctum of all subjects were scanned by AS-OCT, and the images were quantified in order to observe the AS-OCT image features. The outer punctal diameter, punctal depth, tear well diameter and tear well depth were all measured simultaneously. The inferior punctum's punctal reserve and punctal reserve ratio were estimated according to the available parameter data.

RESULTS: 1)The measured parameters conforming to normal distribution were expressed as mean±standard deviation. The observation group's outer punctal diameter, tear well diameter, tear well depth, and punctal reserve ratio were 458.19±63.58μm, 200.34±84.69μm, 188.95±87.50μm and 0.32±0.18, respectively, while the control group's outer punctal diameter, tear well diameter, tear well depth and punctal reserve ratio were 655.53±82.62μm, 230.26±107.02μm, 275.30±144.34μm, 0.46±0.23, respectively. The parameters in observation group were all lower than those of control group(P<0.05); 2)Parameter data that did not conform to normal distribution were expressed as medians and quartiles, and the results were as follows: the punctal depth in the observation group was 265.50μm(interquartile range 204.25-328.77)μm and the punctal reserve was 71.53μm(interquartile range 46.12-111.37)μm, respectively, while the punctal depth in the control group was 468.76μm(interquartile range 420.50-588.88)μm and the punctal reserve was 182.16μm(interquartile range 131.36-309.84)μm. This difference was statistically significant(P<0.05); 3)In the observation group, there was a negative correlation between the epiphora and the outer punctal diameter(r=-0.448, P<0.05), a positive correlation between the epiphora and tear well depth(r=0.335, P<0.05), and a negative correlation between the epiphora and the punctal reserve and punctal reserve ratio coefficient(r=-0.520, -0.566, P<0.05).

CONCLUSION: The AS-OCT can aid in enhancing punctal morphology cognition; The outer punctal diameter and tear well depth are related to the epiphora; The primary punctal stenosis patients with smaller outer punctal diameters are more likely to have the symptom of epiphora, and in patients with punctal stenosis, the greater the potential capacity of the punctum to hold tears, the lesser the degree of epiphora.