Diagnostic performance of swept-source anterior segment optical coherence tomography (SS-OCT) in classifying primary angle closure disease

Abstract

Purpose : Previous studies showed that certain quantitative SS-OCT measurements were correlated with increased intraocular pressure, suggesting a possible association between anatomic anterior chamber configurations with glaucomatous changes. This study aims to evaluate the diagnostic performance of SS-OCT in distinguishing primary angle closure disease from control eyes, as well as primary angle closure (PAC) and primary angle closure glaucoma (PACG) from primary angle closure suspect (PACS) eyes.

Methods : In this cross-sectional study, consecutive adult patients who were diagnosed with PACS, PAC or PACG, and control patients who presented to the Zhongshan Ophthalmic Center from June 2018 to June 2019 were enrolled. A total of 385 eligible eyes from 241 participants underwent a complete ocular examination, including Goldmann applanation, gonioscopy, and SS-OCT. Eight SS-OCT images 45 degrees a part, starting from 0° were analyzed per eye. Anterior segment dimension and angle parameters were measured. The probabilities of PACD vs control, and PACS vs PAC/PACG eyes were modeled as functions of patient demographics and SS-OCT parameters using a gradient boosting machine learning approach, either using all measurements across all 8 images or using individual meriodinal scans only: (0°, 180°), (45°, 225°), (90°, 270°), and (135°, 315°).
Cross-validated area under the receiver operating characteristic curve (cvAUC) of the prediction models were calculated.

Results : SS-OCT showed a strong ability to identify PACD from control subjects with a cvAUC value of 0.94 (0.91, 0.96), with ACD measurement at 180° being the most predictive measurement (Figure 1). Individual meridional scans demonstrated similar diagnostic performance. SS-OCT had a moderate ability in distinguishing PAC and PACG from PACS with a cvAUC value of 0.79 (0.73, 0.85), with lens vault at 270° being the most predictive measurement (Figure 2). The vertical meridional scan (90°-270°) demonstrated the highest cvAUC values of 0.76 (0.70, 0.82).

Conclusions : SS-OCT had excellent diagnostic performance in distinguishing PACD vs control eyes but only moderate performance in distinguishing PAC/PACG eyes vs PACS eyes. As a diagnostic tool, SS-OCT holds potential in associating anterior segment anatomy with its physiologic consequences in understanding the pathway of glaucoma pathogenesis.

This is a 2021 ARVO Annual Meeting abstract.

 

Figure 1

 

Figure 2