Materials that are sewn onto the eye tend to work their way out, that is, they can erode free to the surface, so the tube portion is covered by material from donated eye bank eyes that has been sterilized. The conjunctiva covers over the procedure and most often no sutures need removal.

Most of the pre- and post-operative experiences for trabeculectomy and tube-shunt surgery are similar. A recent study randomly compared tube-shunt surgery to trabeculectomy in eyes that had undergone prior surgery of some kind. In those eyes, the tube cases did as well or better than trabeculectomy in a number of areas, though each kept the pressure at or below target at about the same rate. The tube cases had fewer eyes that went too low in pressure, while the trabeculectomies needed fewer glaucoma eye drops in the short to medium term. Infections would be expected more often with trabeculectomy, but tube operations still can have the tube erode to the surface and may need recovering or removal. As many as one in ten eyes with tube-shunts have double vision for a time. This is because the materials sewn on prevent the eyes from moving together. It usually resolves with time, but in instances when it does not, we can prescribe glasses that will help.

Even more interesting are results of a randomized trial comparing trabeculectomy to tube-shunts in persons having their first glaucoma surgery. Again, both groups did very well, but for those persons who needed to achieve a target eye pressure below 15, trabeculectomy was significantly better, while tube-shunts were equally good for those starting with pressures in the 20s who needed only to be reduced to the high teens.