Risk Factors for Failure in Double-Plate Tube Surgery for Refractory Glaucoma: 25 Years Surgical Experience

Figures & data

Table 1 Sociodemographic and Clinical Data

	Failure (N = 31)		Qualified Success (N = 212)		Total (N = 243)		P value
Age (years)							0.1693
Mean (SD)	56.2	(19)	60.6	(16)	60.1	(17)
Median (IQR)	56	(41;71)	63	(52;73)	63	(51;73)
Min-Max		22–87		18–92		18–92
Sex, (%)							0.2955
Male	14	(45.2)	117	(55.2)	131	(53.9)
Female	17	(54.8)	95	(44.8)	112	(46.1)
Follow-up time (months),							0.9216
Mean (SD)	69.7	(76)	66.4	(63)	66.8	(64)
Median (IQR)	44.3	(23;84)	44.4	(22;93)	44.3	(22;92)
Study eye, (%)							0.6794
Right eye	16	(51.6)	101	(47.6)	117	(48.1)
Left eye	15	(48.4)	111	(52.4)	126	(51.9)

Notes: Ages compared using the Student’s t-test (normal distribution checked). Sex and study eye compared using the Chi² test. Follow-up time: comparison performed using the Wilcoxon test (distribution not normal). There were no significant between-group differences regarding age, sex, and follow-up time.

Abbreviations: SD, standard deviation; IQR, interquartile range.

Table 2 Determination of Failure and Qualified Success by Comparison of the Risk Factors Studied

	Failure (N = 31)		Qualified Success (N = 212)		Total (N = 243)		P value
Preoperative IOP							0.8605
Mean (SD)	36.9	(13)	37.3	(13)	37.3	(13)
Median (IQR)	36	(24;482)	35	(28;46)	35	(26;46)
Min – Max		18–60		12–72		12–72
Etiology, n (%)							0.2248
NVG	10	(32.3)	78	(36.8)	88	(36.2)
Juvenile/congenital glaucoma and syndromes	5	(16.1)	14	(6.6)	19	(7.8)
Aphakia/pseudophakia and AC IOL	5	(16.1)	42	(19.8)	47	(19.3)
Previous failed glaucoma surgery	6	(19.4)	22	(10.4)	28	(11.5)
Penetrant keratoplasty/trauma/complicated intraocular surgery	3	(9.7)	42	(19.8)	45	(18.5)
Uveitis	2	(6.5)	14	(6.6)	16	(6.6)
Tube localization, n (%)							0.5746
AC	15	(48.4)	114	(53.8)	129	(53.1)
PC	16	(51.6)	98	(46.2)	114	(46.9)
Type of implant, no. (%)							0.3536
Double-plate Molteno^® Ophthalmic (Dunedin)	15	(48.4)	84	(39.6)	99	(40.7)
Double-plate implant (FCI S.A.S Paris, France)	16	(51.6)	128	(60.4)	144	(59.3)
Categorized previous surgery, no. (%)							0.3845
No previous surgery	8	(25.8)	71	(33.6)	79	(32.6)
Previous surgery	23	(74.2)	140	(66.4)	163	(67.4)
Number of previous surgeries, no.
Missing data, no.	0		1		1
Mean (SD)	1.7	(2)	1.4	(2)	1.5	(2)
Median (IQR)	2	(0;2)	1	(0;2)	1	(0;2)
Min – Max		0–13		0–9		0–13
Hypertensive phase, no. (%)							0.0612
No	21	(67.7)	174	(82.1)	195	(80.2)
Yes	10	(32.3)	38	(17.9)	48	(19.8)
Treatment before surgery (compounds), no.
Mean (SD)	3	(1)	3	(1)	3	(1)
Median (IQR)	3	(3;3)	3	(3;3)	3	(3;3)
Min-Max		2–4		0–5		0–5
Number of eyedrops before surgery, no.							0.3568
Missing data, no	1		18		19
Mean (Std)	4.7	(2)	4.5	(1)	4.5	(1)
Median (IQR)	5	(4;5)	5	(4;5)	5	(4;5)
[Min - Max]		[2–7]		[0–8]		[0–8]
Preoperative atropine, no. (%)							0.5606
No	22	(73.3)	132	(68.0)	154	(68.8)
Yes	8	(26.7)	62	(32.0)	70	(31.3)
Preoperative beta-blockers, no. (%)							1.0000
No	2	(6.7)	13	(6.7)	15	(6.7)
Yes	28	(93.3)	181	(93.3)	209	(93.3)
Preoperative PGA, no. (%)							0.6871
No	25	(83.3)	154	(80.2)	179	(80.6)
Yes	5	(16.7)	38	(19.8)	43	(19.4)
Preoperative CAI, no. (%)							0.8877
No	21	(70.0)	134	(68.7)	155	(68.9)
Yes	9	(30.0)	61	(31.3)	70	(31.1)
Preoperative brimonidine, no. (%)							0.5338
No	23	(76.7)	154	(81.5)	177	(80.8)
Yes	7	(23.3)	35	(18.5)	42	(19.2)
Preoperative dipivalil-epinephrine, no. (%)							0.4316
No	13	(43.3)	96	(51.1)	109	(50.0)
Yes	17	(56.7)	92	(48.9)	109	(50.0)
Preoperative pilocarpine, no. (%)							1.0000
No	27	(90.0)	167	(88.8)	194	(89.0)
Yes	3	(10.0)	21	(11.2)	24	(11.0)

Notes: Comparison of study eye, tube localization, previous surgery, preoperative atropine, prostaglandins analogues, topical carbonic anhydrase inhibitor, brimonidine and dipivalil-epinephrine treatment performed using the Chi² test. Comparison of etiology and beta-blockers and pilocarpine preoperative treatment performed using the Fisher’s exact test. There is no significant difference between the two groups regarding distribution of all the risk factors studied.

Abbreviations: NVG, neovascular glaucoma; AC IOL, anterior chamber intraocular lens; AC, anterior chamber; PC, posterior chamber; SD, standard deviation; IQR, interquartile; PGA, prostaglandin analogs; CAI, carbonic anhydrase inhibitor.

Table 3 Determination of Partial Success and Complete Success by Comparison of the Risk Factors Studied

	Complete Success (N = 159)		Partial Success (N = 53)		Total (N = 212)		P value
Preoperative IOP no.							0.0054
Mean (SD)	38.8	(14)	33	(11)	37.3	(13)
Median (IQR)	38	(28;50)	32	(25;37)	35	(28;46)
Min-Max	-	12–72	-	15–64	-	12–72
Aetiology, no. (%)							0.0022
NVG	69	(43.4)	9	(17.0)	78	(36.8)
Juvenile/congenital glaucoma and syndromes	8	(5.0)	6	(11.3)	14	(6.6)
Aphakia/pseudophakia and AC IOL	31	(19.5)	11	(20.8)	42	(19.8)
Previous failed glaucoma surgery	12	(7.5)	10	(18.9)	22	(10.4)
Penetrant keratoplasty/trauma/complicated	31	(19.5)	11	(20.8)	42	(19.8)
Intraocular surgery
Uveitis	8	(5,0)	6	(11.3)	14	(6.6)
Previous ocular surgery, no. (%)							0.0217
No previous surgery	60	(38.0)	11	(20.8)	71	(33.6)
Previous surgery	98	(62.0)	42	(79.2)	140	(66.4)
Hypertensive phase, no. (%)							0.0004
No	139	(87.4)	35	(66.0)	174	(82.1)
Yes	20	(12.6)	18	(34.0)	38	(17.9)
Preoperative atropine, no. (%)							0.0022
No	93	(62.4)	39	(86.7)	132	(68.0)
Yes	56	(37.6)	6	(13.3)	62	(32.0)
Preoperative brimonidine, no. (%)							0. 0.0034
No	124	(86.1)	30	(66.7)	154	(81.5)
Yes	20	(13.9)	15	(33.3)	35	(18.5)

Notes: Preoperative IOP and aetiology compared using Fisher’s exact test. Previous surgery, hypertensive phase, and preoperative atropine and brimonidine compared using the Chi² test.

Abbreviations: NVG, neovascular glaucoma; SD, standard deviation; IQR, interquartile range; AC IOL, anterior chamber intraocular lens; IOP, intraocular pressure.

Table 4 Determination of Partial Success and Complete Success by Implant Characteristics and Intraocular Location

	Complete Success (N = 159)		Partial Success (N = 53)		Total (N = 212)		P value
Tube location, no. (%)							0.8736
Anterior chamber	86	(54.1)	28	(52.8)	114	(53.8)
Posterior chamber	73	(45.9)	25	(47.2)	98	(46.2)
Type of implant, no. (%)							0.0095
Double-plate Molteno^® Ophthalmic (Dunedin)	71	(44.7)	13	(24.5)	84	(39.6)
Double-plate silicone implant (FCI S.A.S., France)	88	(55.3)	40	(75.5)	128	(60.4)

Notes: Implant type and tube location compared using the chi² test. There was a significant difference between the two groups regarding the type of implant.

Table 5 Determination of the Hypertensive Phase by Comparison of the Risk Factors Studied

	No (HP) (N = 195)		Yes (HP) (N = 48)		Total (N = 243)		P value
Preoperative IOP	38.4	(13)	32.6	(13)	37.3	(13)	0.0057
Previous surgery, no.(%)							0.0012
No previous surgery	73	(37.4)	6	(12.8)	79	(32.6)
Previous surgery	122	(62.6)	41	(87.2)	163	(67.4)
Aetiology, no. (%)							0.0390
NVG	79	(40.5)	9	(18.8)	88	(36.2)
Juvenile congenital glaucoma and syndromes	12	(6.2)	7	(14.6)	19	(7.8)
Aphakia/pseudophakia AC IOL	38	(19.5)	9	(18.8)	47	(19.3)
Previous failed glaucoma surgery	19	(9.7)	9	(18.8)	28	(11.5)
Penetrant keratoplasty/trauma/complicated intraocular surgery	35	(17.9)	10	(20.8)	45	(18.5)
Uveitis	12	(6.2)	4	(8.3)	16	(6.6)
Tube localization, no. (%)							<0.0001
AC	117	(60.0)	12	(25.0)	129	(53.1)
PC/retroiris	78	(40.0)	36	(75.0)	114	(46.9)
Type of implant, no. (%)							<0.0001
Double-plate Molteno^® Ophthalmic (Dunedin)	95	(48.7)	4	(8.3)	99	(40.7)
Double-plate silicone implant (FCI S.A.S France)	100	(51.3)	44	(91.7)	144	(59.3)

Notes: Preoperative IOP compared using the Student’s t-test (normal distribution checked). Aetiology, tube location and type of implant compared using the Chi² test. There was a significant difference between the two groups regarding preoperative IOP, distribution of the aetiology, tube location, and type of implant.

Abbreviations: NVG, neovascular glaucoma; AC IOL, anterior chamber intraocular lens; AC, anterior chamber; PC, posterior chamber.

Table 6 Determination of the Hypertensive Phase by Comparison of Topical Treatment

	No (N = 195)		Yes (N = 48)		Total (N = 243)		P value
Preoperative treatment, no.	195		48		243
Mean (SD)	3	(1)	3	(1)	3	(1)
Median (IQR)	3	(3;3)	3	(3;3)	3	(3;3)
Min-Max		0–5		0–5		0–5
Preoperative atropine, no. (%)							0.0003
No	116	(63.4)	38	(92.7)	154	(68.8)
Yes	67	(36.6)	3	(7.3)	70	(31.3)
Preoperative beta-blockers, no. (%)							0.0362
No	9	(4.9)	6	(14.6)	15	(6.7)
Yes	174	(95.1)	35	(85.4)	209	(93.3)
Prostaglandin analogues, no. (%)							<0.0001
No	159	(87.4)	20	(50.0)	179	(80.6)
Yes	23	(12.6)	20	(50.0)	43	(19.4)
Preoperative topical carbonic anhydrase inhibitor							0.0004
No	135	(74.2)	20	(46.5)	155	(68.9)
Yes	47	(25.8)	23	(53.5)	70	(31.1)
Preoperative brimonidine, no. (%)							<0.0001
No	155	(86.1)	22	(56.4)	177	(80.8)
Yes	25	(13.9)	17	(43.6)	42	(19.2)
Preoperative dipivalil-epinephrine, no. (%)							<0.0001
No	76	(42.5)	33	(84.6)	109	(50.0)
Yes	103	(57.5)	6	(15.4)	109	(50.0)
Preoperative pilocarpine, no. (%)							0.5823
No	158	(88.3)	36	(92.3)	194	(89.0)
Yes	21	(11.7)	3	(7.7)	24	(11.0)

Notes: Atropine, prostaglandin analogues, topical carbonic anhydrase inhibitor, brimonidine and dipivalil-epinephrine compared using the Chi² test. Beta-blockers and pilocarpine compared using Fisher’s exact test. There was a significant difference between the two groups regarding all preoperative drops except for pilocarpine.

Abbreviations: SD, standard deviation; IQR, interquartile range.

Table 7 Complications Related to the GDD

Fibrine clot	17(22)
Persistent corneal oedema	9(11.7)
Corneal graft rejection	6(7.8)
Shallow or flat anterior chamber	6(7.8)
Diplopia	6(7.8)
Tube repositioning	6(7.8)
Choroidal effusion	4(5.2)
Suprachoroidal haemorrhage	3(3.9)
Aqueous misdirection	3(3.9)
Cystoid macular oedema	3(3.9)
Tube exposure	3(3.9)
Tube retraction	2(2.6)
Tube obstruction	2(2.6)
Dellen	2(2.6)
Sterile endophthalmitis	2(2.6)
Plate exposure	2(2.6)
Severe hypema (>50%)	2(2.6)
Tube breakage	1(1.3)
Tube explantation	1(1.3)
Total number of patients with complications related to the GDD*	77

Notes: *Some patients had more that 1 complication. Data presented in number of patients (percentage).

Table 8 Complications Not Related to the GDD

Retinal detachment/PVR	34(70.8)
Vitreous haemorrhage	3(6.2)
Epiretinal membrane	3(6.2)
Corneal ulcer/abscess	3(6.2)
Orbital cellulitis	2(4.1)
Age related maculopathy	1(2)
Corneal stromal haemorrhage	1(2)
Neovascular subretinal membrane	1(2)
Total number of patients with complications not related to the GDD*	48

Notes: *Some patients had more that 1 complication. Data presented in number of patients (percentage).