Anterior chamber angle measurement with optical coherence tomography: intraobserver and interobserver variability

Area of Science:

• Ophthalmology
• Medical Imaging
• Biomedical Engineering

Background:

• Accurate quantification of anterior chamber parameters is crucial for diagnosing and managing various eye conditions.
• Traditional methods for angle assessment can be subjective, leading to variability.
• Anterior segment optical coherence tomography (AS-OCT) offers a potential objective approach.

Purpose of the Study:

• To evaluate the intraobserver and interobserver variability of AS-OCT for quantifying anterior chamber angle and opening width.
• To establish AS-OCT as a reliable objective diagnostic tool for anterior segment measurements.

Main Methods:

• AS-OCT was used to assess the anterior chamber angle and opening width in 18 eyes of 9 healthy volunteers.
• Two independent observers performed the measurements.
• Intraobserver reproducibility was assessed using intraclass correlation coefficients (ICC) and mixed-effects models.
• Interobserver variability was determined using Bland-Altman analysis.

Main Results:

• High intraobserver reproducibility was found, with ICC values of 0.94 and 0.91 for anterior chamber angle, and 0.97 and 0.93 for opening width.
• Interobserver comparisons demonstrated excellent agreement, with an ICC of 0.96 for both parameters.
• Mean differences were minimal (-0.27° for angle, 2.40 µm for width), with narrow limits of agreement.

Conclusions:

• AS-OCT measurements of anterior chamber angle and opening width exhibit low intraobserver and interobserver variability.
• The technique provides reproducible and objective documentation, confirming its value as a diagnostic tool.
• AS-OCT enhances quantitative assessment and clinical decision-making in ophthalmology.