Comparison of efficacy of intraocular pressure (IOP) reduction between 1- versus 2-site phacotrabeculectomy.The last systematic review concluded that there was weak evidence to suggest that 2-site phacotrabeculectomy provides 1- to 2-mmHg lower IOP than 1-site surgery. Since this study, there have been further publications on this topic, stimulating this meta-analysis.Randomized controlled trials comparing 1- versus 2-site phacotrabeculectomy were searched through August 2009 using MEDLINE and the Cochrane Registry with the keyword phacotrabeculectomy. Inclusion criteria were prospective randomized controlled trials, a minimum of 12 months of follow-up, and English language. Quality of the trials was assessed using Cochrane collaboration's tool of assessing risk of bias. The main outcome measure was IOP, and secondary outcomes included number of glaucoma medications, visual acuity, complications, and surgical time.Ten articles were included. There was no statistically significant difference in the amount of IOP reduction between 1- and 2-site phacotrabeculectomy. The pooled IOP decreases from baseline (95% confidence interval) were: 7.85 mmHg (6.76–8.92 mmHg) versus 5.83 mmHg (4.72–6.94 mmHg) at 1 month; 8.03 mmHg (7.38–8.67 mmHg) versus 7.03 mmHg (6.35–7.71) at 3 months; 7.78 (7.14–8.42) versus 6.75 (6.04–7.46) at 6 months; 6.44 (5.47–7.41 mmHg) versus 6.68 mmHg (5.56–7.81 mmHg) at 12 months; 7.17 mmHg (6.45–7.89 mmHg) versus 6.56 mmHg (5.77–7.35 mmHg) at 24 months; and 7.76 mmHg (7.02–8.49 mmHg) versus 7.14 mmHg (6.36–7.92 mmHg) at 36 months for 1- versus 2-site phacotrabeculectomy, respectively. There was no significant difference in the reduction in glaucoma medications or change in visual acuity at any time point.There is no significant difference in IOP reduction between 1- and 2-site phacotrabeculectomy.The author(s) have no proprietary or commercial interest in any materials discussed in this article.