Reproducibility of Scleral Spur Identification and Angle Measurements Using Fourier Domain Anterior Segment Optical Coherence Tomography
Figure 2
Effect of scleral spur landmark (SSL) location on TISA750 and AOD750. Illustrations show the impact of SSL location on trabecular-iris space area at 750 μm (TISA750) and angle opening distance at 750 μm (AOD750) calculations for nonopen-angle eyes (a) and open-angle eyes (b). If the SSL location is moved by to SSL′ location, TISA750, now based on SSL′, gains the grey area and red area and loses the green area. Both the green area and red area are small relative to the grey area, especially in nonopen-angle eyes (a). In addition, the difference between the green and red areas are negligible (gain red and lose green). Thus, when SSL is moved to SSL′, TISA750 is changed by based on SSL (longer blue line). The SSL location’s impact on AOD750 is dependent on angle width and iris shape (the length of the anterior border of red area). The AOD750 changes are smaller if the angle is nonopen and the iris is straightener.
