There is controversy as to whether AGV implantation has a higher rate of failure in patients with PCG compared with patients with other diagnoses.8,9 While to our knowledge no studies have examined the outcomes of AGV implantation in children with exclusively PCG, Djodeyre et al19 reported shorter mean survival time with AGVs implanted in 17 eyes with congenital glaucoma compared with 18 eyes with other diagnoses (Sturge-Weber syndrome, postoperative glaucoma, etc). Having more than 2 previous glaucoma interventions was also a risk factor for time to failure. However, the criteria for failure included tube malposition, which was defined as any change in the optimal position of the tube or valve plate that resulted in uncontrolled IOP or other complications (tube retraction, tube-endothelium contact, tube-iris contact, valve plate extrusion). In their study, of the 11 eyes that were considered failures, 9 were eyes with congenital glaucoma, with 56% failure secondary to tube malposition. However, in comparison with our study, the follow-up time was shorter at 12 and 24 months. In contrast, other studies have not found any correlation between surgical failure and glaucoma type in the pediatric population.8,9,20,21 One of the largest studies, published by O’Malley Schotthoefer and associates, examined the long-term outcome of aqueous drainage devices in 38 eyes with congenital glaucoma and 32 eyes with aphakic glaucoma. One-year success rates were 92% and 90% in the congenital and aphakic groups, respectively, but these decreased to 42% and 55% after 10 years. In the congenital glaucoma group, AGVs were implanted in 27 of the 38 eyes (71%) and Baerveldt implants were placed in the remainder. In addition, 10 of the 38 eyes (26%) had other nonglaucoma surgical procedures prior to aqueous drainage device placement, including cataract surgery, penetrating keratoplasty, and vitrectomy. Thus, there were significant differences between the patients with congenital glaucoma examined in the study by O’Malley Schotthoefer and associates compared with our study, which included patients with PCG who had only glaucoma surgical procedures previously and had only AGVs implanted.