Efficacy of neodymium-doped yttrium aluminum garnet laser iridotomies in primary angle-closure diseases: superior peripheral iridotomy versus inferior peripheral iridotomy

Abstract

Purpose: To evaluate the efficacy and safety of superior peripheral iridotomy versus inferior peripheral iridotomy in the treatment of primary angle-closure glaucoma (PACG) in phakic patients. Methods: In this randomized, prospective, paired-eye comparative study, patients with primary angle closure or primary angle-closure suspects were recruited and randomized to receive neodymium-doped yttrium aluminum garnet (Nd:YAG) laser peripheral iridotomy (LPI) superiorly in one eye and inferiorly in the other eye. Patients were masked to the location of treatment in each eye. The main outcome measures were patency of iridotomy, intraocular pressure (IOP), complications and visual symptoms at each postoperative visit during a 1 year follow-up. Results: A total of 164 patients were recruited, of whom 150 (91.46) completed the study. The mean age was 58.856.4 years. Average IOP measurements before LPI was 22.85 +/- 7.53 and 23.62 +/- 8.32 in superior LPI and inferior LPI eyes respectively. After LPI, average IOP was 25.14 +/- 2.73 and 20.97 +/- 2.72 in superior LPI and inferior LPI eyes respectively. Inferior LPIs required less use of mean total laser energy to perforate the tissue (p=.05) and resulted in a significantly lower incidence of iris bleeding at the time of treatment (p=.004), lower IOP elevation following treatment (p=.002), lower incidence of focal corneal damage (p=.002) and a lower post-laser iritis (p=.04). All the 300 iridotomies were patent at 12 month follow up. Conclusion: The inferior LPI appeared to be an efficient method of preventing pupil block with fewer complications. Visual symptoms following inferior LPI are similar to superior LPI.