Evaluation of the Lower Punctum Parameters and Morphology Using Spectral Domain Anterior Segment Optical Coherence Tomography

Table 3

Characteristics of the major morphological punctal types detected by OCT and their frequency.

Category	Punctal depth	Outer : inner diameter correlation	Angle of medial wall to inner punctum	Angle of lateral wall to inner punctum	Number (%)
Bicornuate	Deep	2 : 1	Right/obtuse	Right/obtuse	8 (5.4%)
Creeping edge	Shallow	2 : 1	Right	Obtuse	38 (25.8%)
Deep	Deep	1 : 1	Right/parallel	Right/parallel	13 (8.8%)
Flask-shaped	Deep	1 : 1.4	Acute	Acute	7 (4.8%)
Funnel-shaped	Shallow	3 : 1	Obtuse	Obtuse	27 (18.4%)
Saucer-shaped	Shallow	2 : 1	Obtuse	Obtuse	38 (25.8%)
Square-shaped	Shallow	1 : 1	Right/parallel	Right/parallel	16 (10.8%)

There is a characteristic bulge in the inner punctum forming with the walls. A W-shaped appearance. The two diverging walls join the inner punctum in a rounded junction. The two walls form a V-shaped punctum.