Change in Angle Parameters Measured by Anterior Segment Optical Coherence Tomography after Laser Peripheral Iridotomy Alone versus Laser Peripheral Iridotomy and Argon Laser Peripheral Iridoplasty

ABSTRACT

PURPOSE: To compare the changes in angle parameters after laser peripheral iridotomy (LPI) alone versus LPI and ALPI (argon laser peripheral iridoplasty) in primary angle closure patients by using anterior segment optical coherence tomography (AS-OCT). METHODS: A total of 25 eyes from 17 patients with narrow angles were enrolled in this present study. Eleven eyes in the LPI treatment group and 14 eyes in the LPI and ALPI combined treatment group were evaluated using AS-OCT. The anterior chamber depth (ACD), angle opening distance at 500 microm (AOD 500) and 750 microm (AOD 750), angle recess area at 500 microm (ARA 500) and 750 microm (ARA 750), trabecular-iris space area at 500 microm (TISA 500) and 750 microm (TISA 750), trabecular-iris angle (TIA) were measured. The pre- and post-treatment parameters were compared in each group. The parameter changes after laser treatment were also compared. RESULTS: AOD 500, AOD 750, ARA 500, ARA 750, TISA 500 and TISA 750 except ACD significantly increased following LPI treatment (p = 0.013, p = 0.010, p = 0.008, p = 0.003, p = 0.006, p = 0.003, p = 0.013, respectively, Wilcoxon signed rank test) and LPI and ALPI combined therapy (p = 0.001, p = 0.001, p = 0.001, p = 0.001, p = 0.001, p = 0.001, p = 0.001, respectively, Wilcoxon signed rank test). The AOD 500 difference, TISA 500 difference, and TISA 750 difference were significantly greater after LPI and ALPI combined therapy than after LPI treatment alone (p = 0.112, p = 0.147, p = 0.049, p = 0.037, respectively, Mann-Whitney U-test). CONCLUSIONS: The results from the present study showed LPI alone or LPI and ALPI combined therapy significantly widened the anterior chamber angle and combined therapy showed greater effect than LPI alone.