Anterior Chamber Angle Alterations in Bilateral Acute Iris Transillumination Syndrome

Purpose To evaluate anterior chamber angle characteristics in patients with bilateral acute iris transillumination (BAIT) using swept-source anterior segment optical coherence tomography (AS-OCT) and to investigate the diagnostic performance of angle parameters for distinguishing BAIT from healthy controls.Methods This cross-sectional study included 15 patients diagnosed with BAIT and 15 healthy controls with a comparable age and sex distribution. All participants underwent comprehensive ophthalmic examination and anterior segment imaging using the ANTERION swept-source AS-OCT system. Measurements included angle opening distance (AOD), trabecular–iris space area (TISA), scleral spur angle (SSA), aqueous depth (AQD), lens thickness, lens vault, and other anterior segment biometric parameters. Group comparisons were performed. Correlation analyses were conducted to evaluate associations between angle parameters and ocular biometric measurements. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic utility of significant angle parameters.Results Patients with BAIT demonstrated significantly lower AOD and TISA values compared with healthy controls, whereas SSA measurements were comparable between groups. Correlation analysis revealed significant positive associations of AOD, TISA, and SSA measurements with AQD and significant negative associations with lens thickness. ROC analysis demonstrated good discriminatory ability for both AOD750 MIN and TISA750 MIN in distinguishing BAIT eyes from controls. Mean intraocular pressure decreased from 24.4 ± 16.2 mmHg at presentation to 14.7 ± 2.1 mmHg at 12 months, although the difference was not statistically significant (p = 0.226).Conclusions BAIT may be associated with measurable alterations in anterior chamber angle configuration characterized predominantly by reduced AOD and TISA values.