Reply from David Richardson, MD via the FitEyes mailing list:
In general, the answer would be, "No, canaloplasty cannot be done after implantation of a Hydrus." That being said, it would be possible (but likely a tad difficult) to perform Ab-interno canaloplasty (AbiC) of half of the canal after implantation of the Hydrus. I would not bother attempting ab-externo canaloplasty after placement of an iStent or Hydrus because it would not be possible to place the Prolene suture/stent.
In general I prefer to combine AbiC with Hydrus implantation in my patients with Medicare who are also undergoing cataract surgery. I find it provides greater IOP reduction than either MIGS alone and makes it a bit easier to implant the Hydrus. This is just my impression (shared by a few others who also take this approach). However, the Hydrus on it's own is one of the more effective MIGS devices available. Given the choice between the iStent and the Hydrus I wouldn't hesitate to recommend the Hydrus as the better option.
As for removal of the Hydrus, I don't know that anyone has attempted to do that yet, but I see no reason why it couldn't simply be pulled through the trabecular meshwork (essentially creating a partial trabeculotomy).
David Richardson, MD