Factors related to hypertensive phase after glaucoma drainage device implantation

Figures & data

Figure 1 Post-operative tube position in uveitic glaucoma patient.

Figure 2 Slit beam showing post-operative tube position in uveitic glaucoma patient.

Table 1 Baseline characteristics

N=72	n	%
Age (years): mean ± SD	54.75±17.65 years
Sex (female)	29	40.28
Underlying disease
Diabetes mellitus	18	25
Hypertension	25	34.72
Dyslipidemia	14	19.44
Heart disease	8	11.11
Laterality (right eye)	35	48.61
Diagnosis
POAG	10	13.89
PACG	7	9.72
Childhood glaucoma	4	5.56
Secondary glaucoma	51	70.83
Secondary glaucoma (post-corneal transplant)	15	20.83
NVG	12	16.67
Unspecified secondary glaucoma	24	33.33
Pre-operative VA
Equal or better than 20/70	16	22.22
20/70 > VA ≥ 20/200	7	9.72
Worse than 20/200	49	68.05
Pre-operative IOP: mean ± SD	27.1±9.56 mmHg
Lens
Phakic	23	31.94
Pseudophakic	43	59.72
Aphakic	6	8.33
Previous glaucoma surgery
0	23	31.94
1–2	45	62.5
3–4	4	5.56
Pre-operative number of anti-glaucoma medication: median (IQR)	4 (3–4)
Type of GDD
Valve	18	25.00
Non-valve	54	75

Notes: Valve GDD = Ahmed; non-valve GDD = Molteno and Baerveldt.

Abbreviations: POAG, primary open angle glaucoma; PACG, primary angle closure glaucoma; NVG, non-valve glaucoma drainage device; VA, visual acuity; IOP, intraocular pressure; GDD, glaucoma drainage device.

Table 2 Factors related to HP after GDD implantation

	Non-HP	HP	Crude odds ratio	95% CI	p-value	Adjusted odds ratio	95% CI	p-value
	n (%)	n (%)
Age (years)	58.68±18.55	51.24±16.24	0.98	0.95–1.00	0.077	0.98	0.94–1.01	0.182
Dyslipidemia
Yes	9 (64.29)	5 (35.71)	0.42	0.13–1.41	0.161	0.45	0.1–2.05	0.301
No	25 (43.10)	33 (56.90)	1			1
Heart disease
Yes	7 (87.50)	1 (12.50)	0.10	0.01–0.90	0.040	0.06	0–0.72	0.027
No	27 (42.19)	37 (57.81)	1			1
Pre-operative VA
Equal or better than 20/70	4 (25.00)	12 (75.00)	3.39	0.96–12.00	0.058	7.5	1.35–41.35	0.021
20/70 > VA ≥ 20/200	4 (57.14)	3 (42.86)	0.85	0.17–4.19	0.840	1.31	0.21–8.13	0.775
Worse than 20/200	26 (53.06)	23 (46.94)	1			1
Lens
Phakic	9 (39.13)	14 (60.87)	7.78	0.78–77.93	0.081	3.64	0.30–43.96	0.310
Pseudophakic	20 (46.51)	23 (53.49)	5.75	0.62–53.43	0.124	6.66	0.56–79.85	0.135
Aphakic	5 (83.33)	1 (16.67)	1			1
Type of GDD
Non-valve	25 (46.30)	29 (53.70)	1.16	0.40–3.37	0.785	1.17	0.33–4.09	0.81
Valve	9 (50.00)	9 (50.00)	1			1

Notes: Valve GDD = Ahmed; non-valve GDD = Molteno and Baerveldt. Multiple logistic regression. Significance (p<0.05).

Abbreviations: HP, hypertensive phase; GDD, glaucoma drainage device; VA, visual acuity.

Table 3 Pre-operative and 12-month post-operative outcomes

	Pre-operative outcome	Post-operative 12-month outcome	p-value
IOP (mmHg): mean ± SD	27.1±9.56	13.67±5.91	<0.001*
Numbers of medications: median (IQR)	4 (3–4)	1 (0–2)	<0.001*
VA (Snellen): n (%)			0.343#
Equal or better than 20/70	16 (22.22)	13 (18.05)
20/70 > VA ≥ 20/200	7 (9.72)	12 (16.67)
Worse than 20/200	49 (68.05)	47 (65.28)

Notes:

* Wilcoxon signed ranks test compared with pre-operation.

# McNemar Test. Data in bold indicates statistical significance.

Abbreviations: IOP, intraocular pressure; VA, visual acuity.

Table 4 Course of IOP after GDD implantation

	Non-HP	HP	p-value
	Mean ± SD	Mean ± SD
Pre-operation	27.85±10.26	26.42±8.97	0.530
Post-op 1 day	14.56±11.00	15.47±9.67	0.708
Post-op 2 weeks	13.74±6.96	17.50±7.70	0.034
Post-op 1 month	12.06±4.37	21.21±8.41	<0.001
Post-op 2 months	12.18±4.29	15.45±8.29	0.037
Post-op 3 months	13.91±8.01	15.26±8.99	0.505
Post-op 4 months	13.62±5.27	14.76±7.43	0.458
Post-op 6 months	13.03±6.28	13.32±6.61	0.852
Post-op 9 months	12.91±5.23	14.76±7.88	0.250
Post-op 1 year	13.50±5.28	13.82±6.49	0.823
p-value	0.085

Notes: Independent t-test. Generalized linear mixed model adjusted baseline: age, sex, heart disease, pre-operative VA and type of GDD. Significance (p<0.05). Data in bold indicates statistical significance.

Abbreviations: IOP, intraocular pressure; GDD, glaucoma drainage device; HP, hypertensive phase; VA, visual acuity; Post-op, post-operation.

Figure 3 Comparison of IOP after GDD implantation between HP and non-HP groups.

Abbreviations: IOP, intraocular pressure; GDD, glaucoma drainage device; HP, hypertensive phase.

Table 5 Post-operative outcomes

	Non-HP (n=34)	HP (n=38)	p-value	p-value**
	n (%)	n (%)
Failure	12 (50.00)	12 (50.00)	0.738	0.638
Early complication	15 (51.72)	14 (48.28)	0.530	0.701
Late complication	3 (30.00)	7 (70.00)	0.316#	0.078

Notes:

# Fisher’s exact test.

** Logistic regression adjusted-baseline: age, sex, heart disease, pre-operative VA and type of GDD. Significance (p<0.05).

Abbreviations: HP, hypertensive phase; VA, visual acuity; GDD, glaucoma drainage device.

Figure 4 Kaplan–Meier survival curve comparing non-HP and HP group.

Abbreviation: HP, hypertensive phase.