Glaucoma drainage devices are usually placed in the superior quadrants. The superotemporal quadrant is usually the site of choice. However, when the upper fornix is scarred and especially when conjunctiva is two fibrotic to enable adequate coverage of tube with a scleral or other patch graft, some surgeons place the tube in one of inferior quadrants.
In the present study we will compare the outcome and complicatons of both the superior and the inferior approach for inserting Ahmed Valve implants.
