<qa>  What was the main outcome measure of the study?The main outcome measure of the study was intraocular pressure and number of anti-glaucoma medications. Complete success was defined as IOP between 6 and 21 without the use of any glaucoma medication. Partial success was defined as IOP between 6 and 21 with a maximum of 2 glaucoma drops. Overall success rate was the sum of complete and partial success rates. Failure was defined as IOP21, IOP21 with 3 medications, loss of vision, shunt extrusion and need for additional glaucoma surgery. Other outcome measures included best corrected visual acuity BCVA, number of glaucoma medications, and complications. 