In anterior segment OCT, which anatomical landmark is used to start the measurement of an angle?

In anterior segment OCT, which anatomical landmark is used to start the measurement of an angle?

• A. Pupil center
• B. Iris root
• C. Corneal apex
• D. Scleral spur

Answer: (D)

The measurement of the anterior chamber angle in AS-OCT is anchored at a stable, identifiable boundary where the angle begins—the scleral spur. This landmark marks the entry point of the trabecular meshwork and serves as the reference from which angle openness is quantified (for example, using angle-opening distances or related metrics). The pupil center moves with gaze and accommodation, so it isn’t a reliable boundary for angle measurements. The iris root and the corneal apex are not consistent reference points for defining the angle in standard AS-OCT measurements, whereas the scleral spur provides the reproducible starting point needed for accurate, comparable assessments.

The measurement of the anterior chamber angle in AS-OCT is anchored at a stable, identifiable boundary where the angle begins—the scleral spur. This landmark marks the entry point of the trabecular meshwork and serves as the reference from which angle openness is quantified (for example, using angle-opening distances or related metrics). The pupil center moves with gaze and accommodation, so it isn’t a reliable boundary for angle measurements. The iris root and the corneal apex are not consistent reference points for defining the angle in standard AS-OCT measurements, whereas the scleral spur provides the reproducible starting point needed for accurate, comparable assessments.