Iridocorneal Angle Assessment After Laser Iridotomy With Swept-source Optical Coherence Tomography

Aim: To investigate the reliability of anterior chamber angle (ACA) measurements in narrow angles and assess the effect of laser peripheral iridotomy (LPI) on these measurements using novel swept-source optical coherence tomography (SS-OCT) technology. Materials and Methods: In this prospective observational study, patients with gonioscopically narrow angles were enrolled and scheduled for prophylactic LPI. Twelve ACA sections were obtained in each eye using SS-OCT (ANTERION, Heidelberg Engineering, Germany) before and after Nd:YAG LPI. A built-in algorithm calculated ACA measurements after manual identification of the scleral spur and ACA recess. Eight ACA parameters were evaluated: ACA (ACA 500, ACA 750); scleral spur angle (SSA 500, SSA 750); angle opening distance (AOD 500, AOD 750); and trabecular iris space area (TISA 500, TISA 750). The effect of LPI was assessed for each parameter, both nasally and temporally. Results: Ten patients (18 eyes) were enrolled (mean age, 61.8 +/- 13.6 y; 60.0% female individuals). On average, the ACA was wider nasally than temporally (P=0.004). LPI significantly widened the ACA (range, 26.7-29.4%; P