Randomized comparative trial of diode laser transscleral cyclophotocoagulation versus Ahmed glaucoma valve for neovascular glaucoma in Chinese – a pilot study

Figures & data

Table 1 Demographics of study subjects

	TSCP	AGV	P-value
	N (eyes)=9	N (eyes)=13
Mean age (range) in years	61.3±13.5 (39–79)	62.8±11.0 (41–75)	0.79
Gender			0.33
Male	5	8
Female	1	5
Laterality			1.00
Right	3	4
Left	6	9

Abbreviations: AGV, Ahmed glaucoma valve; TSCP, transscleral cyclopho­tocoagulation.

Table 2 Causes of NVG, pre­intervention PRP, lens status, and follow­up duration

	TSCP	AGV	P-value
	N (eyes)=8	N (eyes)=12
Causes of NVG			0.32
Proliferative diabetic retinopathy	4	6
Central retinal vein occlusion	1	4
Central retinal artery occlusion	0	1
Ocular ischemic syndrome	3	1
Pre­intervention PRP			1.00
No	2	3
Yes	6	9
Previous cataract surgery			1.00
No	5	8
Yes	3	4
Mean follow­up durations in months (range)	25.5±16.3 (7–51)	29.1±11.9 (8–52)	0.58

Abbreviations: TSCP, transscleral cyclophotocoagulation; AGV, Ahmed glaucoma valve; NVG, neovascular glaucoma; PRP, panretinal photocoagulation.

Table 3 BCVA changes in the two study groups

	TSCP	AGV	P-value
	N (eyes)=7	N (eyes)=11
BCVA change, n (%)			0.56
Deteriorated	2 (29)	6 (55)
Static	3 (43)	3 (31)
Improved	2 (29)	2 (18)
Eyes developing NLP, n (%)	1 (14)	4 (36)	0.60

Abbreviations: AGV, Ahmed glaucoma valve; BCVA, best­corrected visual acuity; NLP, no light perception; TSCP, transscleral cyclophotocoagulation.

Table 4 Baseline and final mean IOP, number of glaucoma medications, and mean follow-up duration

	TSCP	AGV	P-value
	N (eyes)=6	N (eyes)=6
Mean baseline IOP (mmHg)	42.5±13.9	41.5±11.5	0.90
Mean final IOP (mmHg)	15.2±6.6	14.7±4.2	0.88
Mean number of medications (baseline)	3.2±0.8	2.8±1.5	0.63
Mean number of medications (final)	1.7±1.4	0.5±0.8	0.11
Mean follow­up duration (months)	28.5±17.9	31.0±15.4	0.80

Abbreviations: AGV, Ahmed glaucoma valve; TSCP, transscleral cyclophotocoagulation.

Table 5 Success rates for both groups

	Number of eyes
	TSCP	AGV
Total number of eyes recruited	9	13
Valid cases with a follow­up of >6 months	8	12
Cases following assigned treatment protocol for IOP control throughout the study period	7	7
1. Failed IOP control, n (%)	1 (14)	1 (14)
2. Successful IOP control Excluding the 1 TSCP and 5 AGV eyes that did not follow the assigned protocol, n (%)	6 (86)	6 (86)
Deteriorated BCVA counted as failure, n (%)	2 (25)	6 (50)
*Overall success, n (%) Valid cases – (failed IOP control + deteriorated BCVA)	5 (63)	5 (42)

Note:

* Higher overall success rate with TSCP was not statistically significant (P=0.65).

Abbreviations: AGV, Ahmed glaucoma valve; BCVA, best­corrected visual acuity; TSCP, transscleral cyclophotocoagulation.

Figure 1 Kaplan–Meier survival curves of eyes with medically uncontrolled neovascular glaucoma randomized to either treatment with TSCP or AGV, in terms of overall success, based on an IOP of 21 mmHg or less, without hypotony­related complications, and no worsening of visual acuity, at final visit.

Notes: There was no significant difference in the overall success rate (logrank test, P=0.42) for both groups, although it was insignificantly lower for the AGV group (HR 1.72; 95% CI 0.45, 6.67).
Abbreviations: AGV, Ahmed glaucoma valve; TSCP, transscleral cyclopho­tocoagulation.

Table 6 Treatment­related complications in the Ahmed glaucoma valve group (total of 12 eyes with a follow­up duration of 6 months or more)

	Number of eyes, n (%)
Intraoperative hemorrhage	1 (8)
Corneal decompensation	1 (8)
Over-filtration	2 (17)
Encapsulated bleb	1 (8)
Implant exposure	2 (17)
Rapid cataract progression	1 (8)
Phthisis bulbi	3 (25)

Note: More than one complication can occur in each eye.