Ten-Year Outcome of Glaucoma Drainage Device Surgery After Penetrating Keratoplasty

In eyes with intractable glaucoma, drainage devices provide long-term control of intraocular pressure also after penetrating keratoplasty (PK). There is a high incidence of corneal graft failure.

To compare very long-term results of eyes with glaucoma drainage device (GDD) after PK.

We retrospectively reviewed medical records of all patients who underwent GDD placement after PK at our institution between 2001 and 2017. Forty eyes of 40 patients were studied. Glaucoma outcome was assessed by postoperative intraocular pressure (IOP), number of medications, and need for further glaucoma surgery. Corneal outcome was assessed by graft rejection, failure, and visual acuity. Surgical procedures before and during the study period, and their complications were evaluated.

The mean follow-up was 125.0±52.3 (median, 116.5) months. Twenty of 40 eyes had a follow-up of at least 10 years. The mean preoperative IOP was 34.0±8.3 (median, 32.0) mm Hg with 3.2±1.3 (median, 3.5) glaucoma medications. At last postoperative follow-up, the mean IOP decreased to 12.7±4.9 (median, 14.0) mm Hg with 1.0±1.2 (median, 0.0) glaucoma medications. GDD implantation successfully controlled glaucoma in 88%, 88%, 85%, 80%, 78%, 75%, and 70% of eyes, at 1, 2, 3, 4, 5, 7, and 10 years, respectively. At last follow-up 68% showed glaucoma success. The corneal grafts remained clear in 74%, 63%, 45%, 45%, 37%, 32%, and 26% of eyes at 1, 2, 3, 4, 5, 7, and 10 years, respectively. Only 7 corneal grafts (17.5%) remained clear at last follow-up.

A GDD can successfully control intractable glaucoma even after a very long period of time also after PK. However, the survival of the corneal grafts is low.