Role of laser iridoplasty in the management of angle closure mechanisms other than pupillary block

Purpose: To investigate the treatment outcomes of argon laser peripheral iridoplasty (ALPI) in angle closure mechanisms other than pupillary block. Methods: We conducted a comprehensive chart review to evaluate consecutive patients who underwent ALPI due to unsuccessful laser iridotomy (whenever the angles remained occludable) between July 2009 and April-2012. An occludable angle was defined as the posterior trabecular meshwork not visible for ≥180° without indentation on dark room gonioscopy. Eyes with previous incisional surgery or more than 90° of peripheral anterior synechiae were excluded. Main data collected were age, presence of glaucoma, pre-and postlaser intraocular pressure (IOP), angle-status, and underlying angle closure mechanism. Main outcomes were postALPI angle widening on gonioscopy and magnitude of IOP reduction. Results: A total of 41 eyes (27 patients) with persistent occludable angles were initially included in the analysis, comprising approximately 14% of the 196 patients (321 eyes) that had undergone laser iridotomy during the predefined period. Among these cases, most common angle closure mechanisms were plateau iris (56%) and lens-induced component (34%). Patients with plateau iris were mostly women and younger than those with lens-induced component (p ≤ 0.03). A total of 35 eyes (23 patients) underwent ALPI (63% had glaucoma). Mean IOP was significantly reduced from 18.2 ± 4.7 to 14.6 ± 3.8 (p < 0.01), with no significant difference between patients with plateau iris and lens-induced components (p = 0.22). Over 91% of these eyes showed nonoccludable angles following ALPI (follow-up of 11.8 ± 3.3 months). Conclusion: In this series of middle-aged patients with occludable angles, despite a patent iridotomy, ALPI was a useful procedure independent of the underlying mechanism, leading to angle widening and moderate IOP reduction in most cases.