Though it has long been recognized that glaucoma significantly increases the risk of corneal graft failure, it is unclear whether this effect is intrinsically linked to the underlying corneal disease or dependent on other recipient risk factors.
This study's authors retrospectively analyzed transplants in eyes with and without glaucoma, examining the indication for graft, medical and surgical glaucoma treatment, and other recipient risk factors for graft failure such as vascularization and ocular surface disease. A total of 6,255 transplants in eyes without glaucoma and 1,994 in eyes with glaucoma were included in the review.
Three-year transplant survival was 86 percent in eyes without glaucoma and 72 percent in eyes with glaucoma (P < 0.0001). Failure risk was dependent on the indication for PK, with transplants undertaken for primary corneal endothelial disease carrying a higher risk.
Glaucoma patients undergoing PK for pseudophakic bullous keratopathy (PBK) or Fuchs dystrophy had significantly increased relative risks of graft failure (1.5 and 1.9 with topical and 2.0 and 3.1 with oral antiglaucoma medication, respectively) compared to those without glaucoma. There was no equivalent significant difference for those with keratoconus, previous noncataract ocular surgery, trauma, or noninfectiousulcerative keratitis.
Graft failure was also dependent on the presence of risk factors. Compared to keratoconus, graft failure was significantly increased for patients with PBK (relative risk 3.8), infection (3.2), trauma (4.4), noninfectious ulcerative keratitis (3.7), and Fuchs dystrophy (1.5). The increased risk of graft failure in patients with PBK is consistent with previous reports, but relative risks for infection, trauma, and noninfective ulcerative keratitis have not been previously been demonstrated.
The authors also found that the modality of glaucoma management influenced graft survival. The three-year graft survival rate was 73 percent in eyes with medically managed glaucoma compared to 63 percent in surgically managed glaucoma (P = .07).