Age and sex variation in angle findings among normal Chinese subjects: a comparison of UBM, Scheimpflug, and gonioscopic assessment of the anterior chamber angle.

BACKGROUND: Limited data are published on the ultrasound biomicroscope (UBM) findings of the anterior chamber angle. This work provides a population-based assessment of angle findings and compares 3 modalities for assessing angle dimensions.
METHODS: A sample of 268 persons who had participated in a population-based study of glaucoma prevalence in Singapore were reexamined by UBM (nasal, temporal, and inferior angles only), Scheimpflug photography of angle width, and gonioscopy. Angle findings were compared, and age and sex influences evaluated.
RESULTS: The temporal angle was the widest of the 3 angles imaged with the UBM, and the inferior angle was the narrowest (nearly 20% more narrow than the temporal angle, P<0.005). Women were found to have narrower angles than men and older persons had more narrow angles. Scheimpflug photography did not provide enough detail of the angle to increase our understanding of angle anatomy.
CONCLUSIONS: The data reported support earlier findings that the anterior chamber angle is narrower in older individuals and women. Methods of assessing the angle may themselves influence the appearance of the angle. Limited agreement exists between the angle quantification methods studied. An ideal method of angle assessment would not contact the eye and would not require light be directed at the eye.