To Study the Efficacy of Laser Peripheral Iridoplasty in the Treatment of Eyes With Primary Angle Closure and Plateau Iris Syndrome, Unresponsive to Laser Peripheral Iridotomy, Using Anterior-Segment OCT as a Tool.

Abstract

To use anterior-segment optical coherence tomography (AS-OCT) as a tool to monitor the outcome of iridoplasty in patients with primary angle closure (PAC) and plateau iris syndrome (PIS), who were unresponsive to a previous laser peripheral iridotomy. This was a prospective, observational case control study. Patients diagnosed with PAC and PIS who had undergone laser peripheral iridotomy earlier, but were unresponsive to the procedure, were subjected to an iridoplasty. The intraocular pressure (IOP) and anterior-chamber parameters were measured before and after the procedure, and complications were noted. The patients were followed up for 1 year, and results were analyzed. Twenty-four eyes of 12 patients underwent the iridoplasty procedure. Sixteen eyes were diagnosed as cases of PAC and 8 eyes were diagnosed as cases of PIS. Main outcome measures were the IOP, peripheral anterior synechiae, AS-OCT angle parameters, and complications. After iridoplasty, there was a significant decrease in the IOP from 24.4±5.6 to 16.5±5.4 mm Hg (P<0.001) at the final follow-up. The mean number of antiglaucoma medications decreased from 1.6±0.9 to 0.7±1.1. The medians of the peripheral anterior synechiae extent reduced from 3.5 (quartile range, 1.5 to 6.0) to 2.0 (quartile range, 0.5 to 4.0) clock hours in the PAC group (P<0.001) and from 3.8 (quartile range, 2.0 to 6.5) to 2.5 (quartile range, 0.8 to 5.0) clock hours in the PIS group (P<0.001). Changes in AS-OCT parameters noted were as follows: the AOD500 increased from 0.132±0.016 to 0.179±0.062 mm (P<0.001), TISA500 from 0.085±0.012 to 0.104±0.051 mm (P<0.001), and scleral spur angle from 19.5±2.4 to 26.8±4.5 degrees (P<0.001). No significant changes in the angle-to-angle distance and the crystalline lens rise were found. In eyes with synechial angle closure and PIS that do not show an improvement after an iridotomy, laser peripheral iridoplasty can be very effective. There were no significant complications after the iridoplasty procedure, implying that it is quite safe. This study also demonstrates that AS-OCT can serve as a useful tool to document the preprocedure angle parameters, to note the changes after the procedure, and for the long-term follow-up of these patients.