Abstract
Purpose::
To describe results of treating severe post-keratoplasty glaucoma with the ahmed glaucoma implant model S3.
Methods::
Noncomparative interventional case series.
Results::
Twenty-five patients (27 eyes) underwent implantation of an Ahmed glaucoma implant (model S3) for medically uncontrollable intraocular pressures (IOPs) after penetrating keratoplasty. Most of the eyes had pre-existing glaucoma, and 22 of 27 (81%) were pseudophakic following keratoplasty. Other glaucoma procedures had been performed previously on eleven eyes (40%): diode laser trabeculoplasty (five eyes), trabeculectomy (seven eyes), trans-scleral diode laser cyclophotocoagulation (three eyes), and cyclo-cryotherapy (two eyes). One eye in an aphakic patient required placement of two shunts. Follow-up ranged from 11 to 56 months (mean: 19 months). Two eyes developed phthisis bulbi. Three eyes required repeat keratoplasty, four required lysis of vitreous bands from tube ostia by YAG laser, and three underwent additional pars plana vitrectomy. Mean IOP changed from 26.5 pre-op on minimum 2 topical medications, to 16.5 post-op on minimum one topical medication. No repeat implants were required with the exception of one valve revision 2 months following implantation. Corneal allograft failure occurred in five eyes (20%). Including the re-grafted eyes, 21 eyes (78%) had clear grafts and controlled IOPs at the most recent postoperative examination.
Conclusions::
Overall, maintaining graft clarity and intraocular pressure control in eyes with refractory glaucoma after keratoplasty is challenging. However, the Ahmed S3 implant may prove useful in the management of otherwise uncontrollable glaucoma following penetrating keratoplasty.
Keywords: cornea: clinical science • transplantation • intraocular pressure