Role of Optical Coherence Tomography in Assessing Anterior Chamber Angles

Area of Science:

• Ophthalmology
• Medical Imaging
• Anatomy

Background:

• Gonioscopy is the standard for assessing anterior chamber angles but suffers from interobserver variability.
• There is a need for a reliable, objective method for anterior chamber angle assessment.

Purpose of the Study:

• To compare anterior chamber angle measurements between gonioscopy and Spectral Domain Optical Coherence Tomography (SD-OCT).
• To evaluate SD-OCT's utility in individuals with shallow anterior chambers.

Main Methods:

• A comparative observational study included 101 eyes of 54 patients with shallow anterior chambers.
• Anterior chamber angles were graded using gonioscopy (Shaffer system) and SD-OCT (measuring Trabecular Iris Angle - TIA and Angle Opening Distance - AOD).
• Statistical analysis included Chi-square test, sensitivity, specificity, and predictive values.

Main Results:

• SD-OCT identified narrow angles (TIA ≤ 22°, AOD ≤ 290 μm) in a high percentage of eyes across quadrants.
• Sensitivity for detecting narrow angles was high (90.7% for TIA, 82.2% for AOD).
• Specificity was low (11.7% for TIA, 23.4% for AOD) when compared to gonioscopy.

Conclusions:

• SD-OCT identified narrow angles more frequently than gonioscopy.
• The high sensitivity and low specificity of SD-OCT suggest it may be unreliable for screening narrow anterior chamber angles.
• Further research may be needed to refine SD-OCT's role in angle assessment.