Clinical Outcomes after Combined Ahmed Glaucoma Valve Implantation and Penetrating Keratoplasty or Pars Plana Vitrectomy

In patients with uncontrolled intraocular pressure (IOP) despite prescription of maximum tolerated medical therapy (MTMT), surgical management such as trabeculectomy or glaucoma drainage device (GDD) implantation should be considered. GDD implantation is usually preferred when conventional trabeculectomy has already failed or is likely to fail. Among such refractory patients, some need other forms of simultaneous intraocular surgery. For example, visually significant corneal opacity can present with refractory glaucoma that is not responsive to medical treatment. Patients with iridocorneal endothelial syndrome, herpetic keratouveitis, trauma, aphakic or pseudophakic bullous keratopathy, or congenital glaucoma may need penetrating keratoplasty (PKP). Some patients also present with vitreous hemorrhage and/or retinal detachment, together with uncontrolled IOP; such patients require simultaneous pars plana vitrectomy (PPV) and an IOP-lowering procedure. Simultaneous surgery has both advantages and disadvantages. The principal value of simultaneous surgery is avoidance of multiple procedures. If PKP or PPV is performed on patients with uncontrolled IOP without the use of a simultaneous IOP-lowering procedure, IOP elevation may be aggravated, and an immediate second operation may be required before the initial surgery site has healed. If an IOP-lowering procedure such as GDD implantation alone is initially performed, subsequent PKP or PPV may aggravate the wound associated with implantation, thereby worsening the outcome of the earlier procedure. However, simultaneous surgery may require a longer surgical time, which may in turn be negatively associated with surgical outcome and the prevalence of postoperative complications. In the current study, we evaluated the outcomes of patients undergoing intraocular surgery (PPV or PKP) with concurrent Ahmed glaucoma valve (AGV) implantation. We compared the outcomes to those of patients receiving AGV implantation alone.