Table 9.

Failure in each initial surgical intervention group where failure is defined as IOP > 21 or < 6 mmHg for two consecutive reviews or where further IOP-lowering operation was required or where loss of light perception occurred

Intervention	Total number of eyes	Number of eyes that failed during follow-up	Percentage of eyes that failed during follow-up	Mean follow-up duration
BVT	18	8	44.4%	20.3 (SD 5.5)
TSCPC	36	27	75.0%	20.3 (SD 6.4)
Other	13	7	53.8%	21.0 (SD 6.0)
Overall	67	42	62.7%	20.4 (SD 6.0)

BVT Baerveldt tube, TSCPC trans-scleral cyclophotocoagulation, Other delayed or no surgery, pars plana vitrectomy and trabeculectomy with mitomycin C groups