Lens extraction for chronic angle‐closure glaucoma

Background Primary angle‐closure glaucoma (PACG) is characterized by a rise in intraocular pressure (IOP) secondary to aqueous outflow obstruction, with relative pupillary block being the most common underlying mechanism. There is increasing evidence that lens extraction may relieve pupillary block and thereby improve IOP control. As such, comparing the effectiveness of lens extraction against other commonly used treatment modalities can help inform the decision‐making process. Objectives To assess the effectiveness of lens extraction compared with other interventions in the treatment of chronic PACG in people without previous acute angle‐closure attacks. Search methods We searched CENTRAL, MEDLINE, Embase, one other database, and two trials registers (December 2019). We also screened the reference lists of included studies and the Science Citation Index database. We had no date or language restrictions. Selection criteria We included randomized controlled trials (RCTs) comparing lens extraction with other treatment modalities for chronic PACG. Data collection and analysis We followed standard Cochrane methodology. Main results We identified eight RCTs with 914 eyes. We obtained data for participants meeting our inclusion criteria for these studies (PACG only, no previous acute angle‐closure attacks), resulting in 513 eyes included in this review. The participants were recruited from a diverse range of countries. We were unable to conduct meta‐analyses due to different follow‐up periods and insufficient data. One study compared phacoemulsification with laser peripheral iridotomy (LPI) as standard care. Participants in the phacoemulsification group were less likely to experience progression of visual field loss (odds ratio [OR] 0.35, 95% confidence interval [CI] 0.13 to 0.91; 216 eyes; moderate certainty evidence), and required fewer IOP‐lowering medications (mean difference [MD] ‐0.70, 95% CI ‐0.89 to ‐0.51; 263 eyes; moderate certainty evidence) compared with standard care at 12 months. Moderate certainty evidence also suggested that phacoemulsification improved gonioscopic findings at 12 months or later (MD ‐84.93, 95% CI ‐131.25 to ‐38.61; 106 eyes). There was little to no difference in health‐related quality of life measures (MD 0.04, 95% CI ‐0.16 to 0.24; 254 eyes; moderate certainty evidence), and visual acuity (VA) (MD 2.03 ETDRS letter, 95% CI ‐0.77 to 4.84; 242 eyes) at 12 months, and no observable difference in mean IOP (MD ‐0.03mmHg, 95% CI ‐2.3