Diagnostic Accuracy of Anterior Segment Optical Coherence Tomography for Detection of Anterior Chamber Angle Closure: A Comparison with Gonioscopy

Objectives: To determine the diagnostic accuracy of anterior segment OCT in the assessment of anterior chamber angle closure, keeping gonioscopy as the gold standard. Study design: Cross-sectional study Place and Duration of Study: Armed Forces Institute of Ophthalmology, Pakistan Emirates Military Hospital, Rawalpindi, Pakistan, from Mar 23 to Feb 24. Methodology: A total of 140 patients aged≥40 years diagnosed with or suspected of angle-closure glaucoma, having healthy corneas, were included in this study. Gonioscopy was conducted using a Goldmann 3-mirror lens under dim illumination. Anterior segment OCT imaging was conducted using a spectral-domain OCT device equipped with an anterior segment module lens. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of anterior segment OCT for determining anterior segment angle closure were calculated, keeping gonioscopy as the gold standard. Results: The age range of patients in this study was 43-67 years, with a mean age of 56.61±6.8 years. Anterior segment OCT diagnosed 74(52.86%) of cases, while gonioscopy diagnosed 69(49.24%) of cases with anterior chamber angle closure. Anterior segment OCT showed sensitivity of 62.32%, specificity of 56.34%, positive predictive value of 58.12%, and negative predictive value of 60.61%. The diagnostic accuracy was 59.3% (p = 0.03). Conclusion: The moderate performance of anterior chamber OCT suggests that this technique is a good non-invasive method for anterior chamber angle closure assessment, but relying on it alone poses risks of missed diagnoses and false positives. It should be used alongside gonioscopy for a more reliable evaluation.