Purpose. To evaluate intraobserver and interobserver agreement in locating the scleral spur landmark (SSL) and anterior chamber angle measurements obtained using Fourier Domain Anterior Segment Optical Coherence Tomography (ASOCT) images. Methods. Two independent, masked observers (SR and AZC) identified SSLs on ASOCT images from 31 eyes with open and nonopen angles. A third independent reader, NPB, adjudicated SSL placement if identifications differed by more than 80 μm. Nine months later, SR reidentified SSLs. Intraobserver and interobserver agreement in SSL placement, trabecular-iris space area (TISA750), and angle opening distance (AOD750) were calculated. Results. In 84% of quadrants, SR's SSL placements during 2 sessions were within 80 μm in both the X- and Y-axes, and in 77% of quadrants, SR and AZC were within 80 μm in both axes. In adjudicated images, 90% of all quadrants were within 80 μm, 88% in nonopen-angle eyes, and 92% in open-angle eyes. The intraobserver and interobserver correlation coefficients (with and without adjudication) were above 0.9 for TISA750 and AOD750 for all quadrants. Conclusions. Reproducible identification of the SSL from images obtained with FD-ASOCT is possible. The ability to identify the SSL allows reproducible measurement of the anterior chamber angle using TISA750 and AOD750.

Purpose. To investigate age- and position-related changes of anterior chamber angle anatomy in normal, healthy eyes. Patients and Methods. Thirty subjects were separated into a younger and older cohort. The superior and inferior anterior chamber angles of the eyes were measured in supine and sitting positions by ultrasound biomicroscopy (UBM) with bag/balloon technology. Statistical analysis was used to evaluate positional and age-related changes in angle morphology. Results. In the younger cohort, no location or positional differences in angle anatomy were observed. In the older cohort, the inferior quadrant was significantly narrower than the superior quadrant (P = 0.0186) in the supine position. This cohort also demonstrated an interaction effect between position and location. In the older cohort, the angle was deeper inferiorly while the subject was sitting but was deeper superiorly while the subject was supine. Conclusion. Comparison of positional variations in anterior chamber angle anatomy as measured by UBM has recently become possible. This study found that age-related positional changes in the anterior chamber angle anatomy exist in normal healthy eyes.

Purpose. To evaluate outcomes of peripheral iridotomy (PI) for initial management of primary angle closure suspects (PACS), chronic primary angle closure (CPAC), and chronic primary angle closure glaucoma (CPACG). Patients and Methods. Seventy-nine eyes with PACS, CPAC, or CPACG and better than 20/50 visual acuity that underwent PI as initial management were included. Eyes with previous acute angle closure attacks, laser trabeculoplasties, surgeries, or intraocular injections were excluded. Additional treatments, glaucomatous progression, intraocular pressure, visual acuity, and the number of medications were evaluated. Results. The mean followup was 57.1 ± 29.0 months (range 13.8–150.6 months). Sixty-eight eyes (86.1%) underwent additional medical, laser, or surgical treatment. Forty eyes (50.6%) underwent lens extraction due to reduced visual acuity. The mean 10× logMAR visual acuity score for all patients significantly declined from 0.94 ± 1.12 at baseline to 1.83 ± 3.49 (N = 79, P = 0.0261) at the last followup. Conclusions. Most patients who undergo PI for CPAC spectrum will require additional intervention for either IOP lowering or improvement of visual acuity. This suggests that a procedure that not only deepens the angle but also lowers IOP and improves visual acuity would be desirable as further intervention could be avoided. Evaluation of techniques that achieve all 3 goals is warranted.