Prospective, randomized study of one, two, or three trabecular bypass stents in open-angle glaucoma subjects on topical hypotensive medication

Figures & data

Figure 1 The iStent.

Table 1 Demographics and preoperative characteristics: ITT population

	One-stent group (n=38)	Two-stent group (n=41)	Three-stent group (n=40)
Age (years), mean ± SD; range	68.1±9.1; 49–83	67.8±9.3; 51–83	60.9±8.1; 49–85
Sex, male/female	27/11	19/22	19/20
Race, white/other	38/0	41/0	39/0
Eye, OD/OS	23/15	21/20	17/23
Glaucoma diagnosis, POAG/PEX	38/0	40/1	39/0
Lens status, phakic/pseudophakic	37/1	41/0	38/1
Visual field, MD (dB), mean ± SD	−4.72±4.42	−5.20±5.65	−4.81±4.22
C:D ratio, mean ± SD	0.68±0.11	0.71±0.14	0.70±0.12
Pachymetry (µm), mean ± SD	528.4±34.3	541.1±38.3	523.3±37.0
Number of medications at screening,^Table Footnote1 mean ± SD	1.71±0.61	1.76±0.54	1.51±0.69
Preoperative medicated IOP (mmHg), mean ± SD	19.8±1.3	20.1±1.6	20.4±1.8
Postwashout IOP (mmHg), mean ± SD	25.0±1.1	25.0±1.7	25.1±1.9
BCVA (logMAR), mean ± SD	0.28±0.34	0.39±0.40	0.24±0.35

Notes:

1 All subjects qualified for the study based on the use of two medications. Some subjects stopped medication use prior to the screening visit. The mean (SD) values for number of medications at screening reflect the medications subjects were taking at the time of the screening exam.

Abbreviations: ITT, intent-to-treat; SD, standard deviation; OD, oculus dexter (right eye); OS, oculus sinister (left eye); POAG, primary open-angle glaucoma; PEX, pseudoexfoliative glaucoma; MD, mean deviation; C:D, cup:disk; IOP, intraocular pressure; BCVA, best-corrected visual acuity; MAR, minimum angle of resolution.

Figure 2 Proportional analyses of month 12 IOP without medication: modified ITT population.

Abbreviations: IOP, intraocular pressure; ITT, intent-to-treat.

Table 2 Proportional analyses of month 12 IOP without medication: modified ITT population

Month 12 IOP	One-stent group (n=37), n (%) (95% CI)	Two-stent group (n=41), n (%) (95% CI)	Three-stent group (n=38), n (%) (95% CI)
IOP reduction ≥20% vs baseline IOP	33 (89.2%)	37 (90.2%)	35 (92.1%)
	(74.6%–97.0%)	(76.9%–97.3%)	(78.6%–98.3%)
IOP ≥18 mmHg	33 (89.2%)	37 (90.2%)	35 (92.1%)
	(74.6%–97.0%)	(76.9%–97.3%)	(78.6%–98.3%)
IOP ≤15 mmHg	24 (64.9%)	35 (85.4%)	35 (92.1%)
	(47.5%–79.8%)	(70.8%–94.4%)	(78.6%–98.3%)

Abbreviations: IOP, intraocular pressure; ITT, intent-to-treat; CI, confidence interval.

Table 3 Detail of subjects with postoperative medication added

Subject identification	Postoperative exam when medication^Citation1 added	IOP when medication added
One-stent group
8	Month 1	21 mmHg
63	Month 3	19 mmHg
80	Month 3	19 mmHg
5	Month 6	19 mmHg
10	Month 18	17.7 mmHg
51	Month 18	18.3 mmHg
101	Month 18	18 mmHg
Two-stent group
87	Month 3^Table Footnote1	20 mmHg
94	Month 6	19 mmHg
107	Month 6	18.7 mmHg
119	Month 6	19 mmHg
Three-stent group
92	Month 3	18 mmHg
71	Month 6	19 mmHg
74	Month 6	18.3 mmHg

Notes:

1 Subject 87 was prescribed two medications at the end of the month 3 exam. All other subjects were prescribed one medication.

Abbreviation: IOP, intraocular pressure.

Figure 3 Pairwise group comparisons of month 18 unmedicated IOP reduction.

Abbreviation: IOP, intraocular pressure.

Table 4 Mean IOP (mmHg) and proportion of eyes on medications: available eyes at each exam¹

	Screening	Baseline	Month 1	Month 3	Month 6	Month 12	Months 12–13^Table Footnote2	Month 18
One-stent group
n	38	38	38	38	38	37	37	36
Mean IOP (SD)	19.8 (1.3)	25.0 (1.1)	12.2 (3.1)	12.8 (2.3)	13.1 (1.7)	14.4 (1.2)	14.9 (1.9)	15.6 (1.5)
On medication, n (%)	38 (100%)	0 (0%)	0 (0%)	1 (2.6%)	3 (7.9%)	4 (10.8%)	0 (0%)	4 (11.1%)
Two-stent group
n	41	41	41	41	41	41	41	41
Mean IOP (SD)	20.1 (1.6)	25.0 (1.7)	12.5 (2.7)	13.0 (2.1)	13.5 (2.3)	12.8 (1.4)	13.6 (2.1)	13.8 (1.3)
On medication, n (%)	41 (100%)	0 (0%)	0 (0%)	0 (0%)	1 (2.4%)	4 (9.8%)	0 (0%)	4 (9.8%)
Three-stent group
n	40	40	40	40	40	38	38	38
Mean IOP (SD)	20.4 (1.8)	25.1 (1.9)	12.0 (2.7)	12.8 (2.0)	12.9 (2.0)	12.2 (1.5)	12.7 (2.1)	12.1 (1.2)
On medication, n (%)	40 (100%)	0 (0%)	0 (0%)	0 (0%)	1 (2.5%)	3 (7.9%)	0 (0%)	3 (7.9%)

Notes:

1 IOP and medication data at the start of the exam are reported. Data were included for subjects who had not undergone secondary surgical interventions that might confound results.

2 Eleven eyes were washed out of medication at month 12. Months 12–13 IOP = month 12 IOP for 105 eyes on no medication, and month 13 IOP for eleven eyes washed out of medication at month 12.

Abbreviations: IOP, intraocular pressure; SD, standard deviation.

Table 5 Month 18 mean IOP and change in mean IOP vs screening and baseline exams: available eyes¹ without medication

Mean IOP and change in mean IOP at month 18	One-stent group, n=32	Two-stent group, n=37	Three-stent group, n=35
Mean ± SD IOP for eyes without medication (mmHg)	15.93±0.90	14.07±1.00	12.24±1.12
Change (%) from screening medicated IOP (mmHg)	−3.94 (−19.5)	−5.99 (−29.5)	−8.19 (−39.7)
Change (%) from baseline unmedicated IOP (mmHg)	−9.04 (−36.1)	−10.77 (−43.2)	−12.61 (−50.6)

Note:

1 Data were included for subjects who had not undergone secondary surgical interventions that might confound results.

Abbreviations: IOP, intraocular pressure; SD, standard deviation.

Table 6 BCVA by visit: ITT population

	Preoperative	Month 1	Month 3	Month 6	Month 12	Month 18
One-stent group (n=38)
20/40 or better	26 (68%)	28 (74%)	29 (76%)	28 (74%)	29 (76%)	30 (79%)
20/100 or better	33 (87%)	33 (87%)	33 (87%)	33 (87%)	34 (89%)	34 (89%)
20/200 or better	38 (100%)	38 (100%)	38 (100%)	38 (100%)	38 (100%)	38 (100%)
Two-stent group (n=41)
20/40 or better	25 (61%)	27 (66%)	27 (66%)	27 (66%)	27 (66%)	27 (66%)
20/100 or better	31 (76%)	33 (80%)	33 (80%)	33 (80%)	33 (80%)	33 (80%)
20/200 or better	41 (100%)	41 (100%)	41 (100%)	41 (100%)	41 (100%)	41 (100%)
Three-stent group (n=40)
20/40 or better	29 (73%)	31 (78%)	31 (78%)	31 (78%)	32 (80%)	32 (80%)
20/100 or better	35 (88%)	35 (88%)	35 (88%)	35 (88%)	35 (88%)	35 (88%)
20/200 or better	40 (100%)	40 (100%)	40 (100%)	40 (100%)	40 (100%)	40 (100%)

Abbreviations: BCVA, best-corrected visual acuity; ITT, intent-to-treat.

QuigleyHAGlaucomaLancet20113771367137721453963

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