Postoperative outcomes following trabeculectomy and nonpenetrating surgical procedures: a 5-year longitudinal study

Figures & data

Table 1 Baseline patient characteristics and study follow-up

	TE (n=148)	PTE (n=129)	VC ± combined phaco (n=104)	p-value
Gender				0.4184
Male, n (%)	72 (48.6)	71 (55.0)	46 (44.2)
Female, n (%)	76 (51.4)	58 (45.0)	58 (55.8)
Age				0.4927
Mean (SD)	63.5 (11.1)	68.34 (11.4)	67.9 (8.8)
Range	39–81	59–80	52–82
Glaucoma type				0.1350
POAG, n (%)	126 (85.1)	105 (81.4)	88 (84.6)
PACG, n (%)	13 (14.9)	24 (18.6)	16 (15.4)
Ocular characteristics				0.3137
Left eye, n (%)	77 (52.0)	72 (55.8)	52 (50.0)
Right eye, n (%)	71 (48.0)	57 (44.2)	52 (50.0)
Presenting IOP				0.0980
mmHg (SD)	26.4 (9.5)	25.2 (7.1)	23.8 (6.8)
Range	10–66	12–55	11–48
Preoperative IOP				0.0199
mmHg (SD)	23.2 (7.1)	23.4 (8.3)	20.2 (4.2)
Range	8–42	10–47	12–35
Preoperative IOP-lowering medications				0.04486
Number of medications, n (SD)	2.7 (0.9)	2.5 (0.9)	2.3 (0.9)
Preoperative BCVA				0.0009
Median LogMAR (IQR)	0.18 (0.02–0.22)	0.2 (0.18–0.32)	0.3 (0.18–0.5)
Preoperative HVF 24-2				0.0176
MD (SD)	−12.96 (6.72)	−13.90 (7.49)	−12.77 (8.44)
Total follow-up (months)
Mean (SD)	22.1 (11.3)	23.2 (11.5)	26.5 (13.3)
Range	12–60	12–48	12–60

Abbreviations: TE, trabeculectomy; PTE, phacotrabeculectomy; VC, viscocanalostomy; phaco, phacoemulsification/intraocular lens; POAG, primary open-angle glaucoma; PACG, primary angle closure glaucoma; IOP, intraocular pressure; BCVA, best-corrected visual acuity; IQR, interquartile range; HVF, Humphrey visual field; MD, mean deviation.

Table 2 Success rates at last follow-up

	TE (n=148)	PTE (n=129)	VC ± combined phaco (n=104)	p-value
Complete success
All patients (%)	139 (93.9)	118 (91.5)	98 (94.2)	0.0007
POAG (%)	118 (93.7)	95 (90.5)	83 (94.3)	0.0015
PACG (%)	12 (92.3)	2 (94.1)	1 (6.3)	0.1563
Qualified success
All patients (%)	5 (3.4)	6 (4.7)	3 (2.9)	0.0012
POAG (%)	4 (3.4)	5 (3.9)	3 (3.4)	0.0011
PACG (%)	1 (3.3)	1 (0.8)	0 (0)	0.1205
Failure
All patients (%)	4 (2.7)	5 (3.9)	3 (2.9)	0.0052
POAG (%)	4 (3.4)	4 (3.8)	2 (2.3)	0.0011
PACG (%)	0 (0)	1 (2.9)	1 (6.3)	0.0837

Abbreviations: TE, trabeculectomy; PTE, phacotrabeculectomy; VC, viscocanalostomy; phaco, phacoemulsification/intraocular lens; POAG, primary open-angle glaucoma; PACG, primary angle closure glaucoma.

Table 3 IOP profiles (mean [SD]), BCVA profiles (median [IQR]), and HVF 24-2 performance (mean [SD])

	TE (n=148)	PTE (n=129)	VC (n=104)	p-value
IOP mmHg (SD)
Preoperative	23.2 (7.1)	23.4 (8.3)	20.2 (4.2)	0.0234
1 month	9.7 (3.8)	12.2 (3.6)	13.9 (4.4)	0.0003
3 months	10.9 (3.9)	13.4 (4.2)	14.1 (4.2)	0.0002
6 months	11.8 (4.6)	13.9 (3.9)	14.2 (3.6)	0.0002
1 year	12.8 (4.7)	14.6 (5.0)	15.3 (3.8)	0.0021
2 years	12.9 (4.2)	16.0 (4.7)	15.5 (4.0)	0.0045
3 years	13.1 (5.4)	14.9 (3.8)	16.3 (2.9)	0.0271
4 years	13.0 (4.2)	14.9 (7.1)	16.6 (3.0)	0.0134
BCVA median LogMAR (IQR)
Preoperative	0.18 (0.02–0.22)	0.2 (0.18–0.32)	0.3 (0.18–0.5)	0.0009
1 month	0.20 (0.12–0.30)	0.34 (0.18–0.44)	0.20 (0.14–0.30)	0.0289
3 months	0.18 (0.02–0.28)	0.2 (0.18–0.30)	0.18 (0.10–0.18)	0.0016
6 months	0.18 (0.10–0.30)	0.2 (0.10–0.30)	0.18 (0.05–0.20)	0.0416
1 year	0.20 (0.10–0.26)	0.18 (0.10–0.30)	0.18 (0.05–0.22)	0.0172
2 years	0.20 (0.04–0.31)	0.2 (0.10–0.40)	0.20 (0.12–0.24)	0.0351
3 years	0.22 (0.10–0.34)	0.22 (0.06–0.43)	0.20 (0.10–0.34)	0.06815
4 years	0.36 (0.20–0.60)	0.2 (0.16–0.30)	0.21 (0.13–0.28)	0.0467
Mean deviation, mean (SD)
Preoperative	−12.96 (6.72)	−13.90 (7.49)	−12.77 (8.44)	0.0176
1 month	−12.88 (6.89)	−12.88 (5.21)	−12.31 (7.92)	0.1437
3 months	−12.13 (7.84)	−14.26 (6.32)	−12.52 (8.95)	0.0739
6 months	−11.36 (7.68)	−15.30 (6.92)	−11.24 (7.75)	0.0047
1 year	−14.94 (8.21)	−14.08 (7.15)	−11.86 (8.79)	0.0044
2 years	−12.24 (7.18)	−16.96 (7.65)	−10.89 (7.75)	0.0001
3 years	−15.65 (7.83)	−16.38 (8.54)	−12.20 (9.21)	0.0302
4 years	−19.85 (6.51)	−15.14 (8.71)	−11.86 (9.58)	0.2788

Abbreviations: IOP, intraocular pressure; BCVA, best-corrected visual acuity; HVF, Humphrey visual field; IQR, interquartile range; TE, trabeculectomy; PTE, phacotrabeculectomy; VC, viscocanalostomy.

Table 4 Linear regression estimated coefficients of IOP at 1-year follow-up

	Estimate	Standard error	t-statistic	p-value
TE
(Intercept)	1.8446	1.3878	1.3291	0.18648
Preoperative BCVA	−0.5656	1.2505	−0.45229	0.65193
Preoperative IOP	0.069944	0.037012	1.8898	0.061347
Preoperative MD	−0.060344	0.038653	−1.5612	0.12128
Postoperative BCVA at 3 months	3.4264	2.4723	1.3859	0.1685
Postoperative IOP at 3 months	0.044491	0.086579	0.51388	0.60834
Postoperative BCVA at 6 months	−4.7577	2.271	−2.095	0.038409
Postoperative IOP at 6 months	0.7561	0.074223	10.187	0.109917
Postoperative BCVA at 1 year	0.82468	1.4068	0.5862	0.55891
PTE
(Intercept)	5.8161	2.387	2.4366	0.016817
Preoperative BCVA	0.91688	1.2924	0.70944	0.47991
Preoperative IOP	0.021982	0.047813	0.45974	0.64682
Preoperative MD	−0.031443	0.057459	−0.54723	0.58559
Postoperative BCVA at 3 months	−2.8912	3.2134	−0.89971	0.3707
Postoperative IOP at 3 months	−0.03079	0.11449	−0.26894	0.7886
Postoperative BCVA at 6 months	6.2465	3.2539	1.9197	0.058099
Postoperative IOP at 6 months	0.60766	0.12121	5.0132	0.705306
Postoperative BCVA at 1 year	−4.5083	2.0104	−2.2425	0.027414
VC
(Intercept)	11.692	2.5272	4.6263	1.5011e–05
Preoperative BCVA	3.4322	1.4771	2.3235	0.022825
Preoperative IOP	0.10263	0.06919	1.4833	0.14212
Preoperative MD	0.019055	0.051755	0.36818	0.71377
Postoperative BCVA at 3 months	−2.3511	3.7806	−0.62188	0.53588
Postoperative IOP at 3 months	0.11755	0.12244	0.96007	0.34006
Postoperative BCVA at 6 months	1.1678	1.8681	0.6251	0.53377
Postoperative IOP at 6 months	−0.13546	0.098369	−1.3771	0.17254
Postoperative BCVA at 1 year	−1.6639	2.2009	−0.75601	0.45198

Note: Number of observations: 104, error degrees of freedom: 76, root mean squared error: 3.54, R²: 0.261, adjusted R²: 0.14, F-statistic vs constant model: 2.24, p-value =0.0177.

Abbreviations: IOP, intraocular pressure; TE, trabeculectomy; BCVA, best-corrected visual acuity; MD, mean deviation; PTE, phacotrabeculectomy; VC, viscocanalostomy.

Table 5 Summary of main postoperative complications

Complications, n (%)	TE (n=148)	PTE (n=129)	VC (n=104)	Total (n=381)
Transient hypotony	36 (24.3)	12 (9.3)	17 (16.3)	65 (17.1)
Hyphaema	4 (2.7)	0	1 (0.9)	5 (1.3)
Shallow AC	9 (6.1)	5 (3.9)	4 (3.8)	18 (4.7)
Bleb leak	4 (2.7)	2 (1.6)	1 (1.0)	7 (1.8)
Decompression retinopathy	1 (0.7)	0	0	1 (0.3)
Iris prolapsed	2 (1.4)	0	0	2 (0.5)
Endophthalmitis	1 (0.7)	0	0	1 (0.3)
Lens malposition	N/A	1	N/A	N/A

Abbreviations: TE, trabeculectomy; PTE, phacotrabeculectomy; VC, viscocanalostomy; AC, anterior chamber; N/A, nonapplicable.