Table 5C: Efficacy outcomes of two versus three first generation iStent implantation

		Two iStents						Three iStents						Meta-Analysis
Outcome		Mean		Standard deviation		Number of eyes		Mean		Standard deviation		Number of eyes		Weighted mean difference		95%CI –Lower bound		95%CI –Upper bound		p-value
IOP reduction		6.03		4.66		287		9.33		6.23		63		–3.30		–4.93		–1.67		p <0.001
Preoperative IOP		21.07		3.66		240		22.52		4.50		63		–1.45		–2.65		–0.25		p = 0.02
Postoperative IOP		13.78		1.62		240		13.23		1.80		63		0.55		0.06		1.04		p = 0.03
Reduction in medications		1.20		0.51		287		1.74		0.53		63		–0.54		–0.68		–0.40		p <0.001
Preoperative medications		2.21		0.48		336		1.94		0.75		63		0.27		0.08		0.46		p = 0.006
Postoperative medications		0.95		0.64		336		0.21		0.22		63		0.74		0.65		0.83		p <0.001

*IOP = Intraocular pressure. CI = Confidence interval. n/a = Not available. Note: Red text denotes endpoints that substantially differed from those of the original analysis.