Factors associated with corneal graft survival in the cornea donor study

Abstract

Importance: The Cornea Donor Study (CDS) showed that donor age is not a factor in survival of most penetrating keratoplasties for endothelial disease. Secondary analyses confirm the importance of surgical indication and presence of glaucoma in outcomes at 10 years.

Objective: To assess the relationship between donor and recipient factors and corneal graft survival in the CDS.

Design, setting, and participants: Multicenter prospective, double-masked, controlled clinical trial conducted at 80 clinical sites. One hundred five surgeons enrolled 1090 participants undergoing corneal transplant for a moderate-risk condition, principally Fuchs dystrophy or pseudophakic or aphakic corneal edema (PACE). Forty-three eye banks provided corneas.

Interventions: Corneas from donors younger than 66 years and donors 66 years or older were assigned, masked to donor age. Surgery and postoperative care were performed according to the surgeons' usual routines. Participants were followed up for as long as 12 years.

Main outcomes and measures: Graft failure, defined as a regrafting procedure or a cloudy cornea for 3 consecutive months.

Results: The 10-year cumulative probability of graft failure was higher in participants with PACE than in those with Fuchs dystrophy (37% vs 20%; hazard ratio [HR], 2.1 [99% CI, 1.4-3.0]; P < .001) and in participants with a history of glaucoma before penetrating keratoplasty, particularly with prior glaucoma surgery (58% with prior glaucoma surgery and use of medications to lower intraocular pressure at the time of surgery vs 22% with no history of glaucoma surgery or medication use; HR, 4.1 [99% CI, 2.2-7.5]; P < .001). We found trends toward increased graft failure in recipients who were 70 years or older compared with those younger than 60 years (29% vs 19%; HR, 1.2 [99% CI, 0.7-2.1]; P = .04) or were African American (HR, 1.5; P = .11) or who had a history of smoking (35% vs 24%; HR, 1.6 [99% CI, 0.9-2.8]; P = .02). Lower endothelial cell density (ECD) and higher corneal thickness (CT) at 6 months (6% vs 41% for ECD ≥2700 vs <1700 cells/mm2 [P < .001]; 14% vs 36% for CT <500 vs ≥600 μm [P = .001]), 1 year (4% vs 39% for ECD ≥2700 vs <1700 cells/mm2 [P < .001]; 18% vs 28% for CT <500 vs ≥600 μm [P = .04]), and 5 years (2% vs 29% for ECD ≥1500 vs <500 cells/mm2 [P < .001]; 7% vs 34% for CT <550 vs ≥650 μm [P < .001]) were associated with subsequent graft failure.

Conclusions and relevance: Most penetrating corneal grafts for Fuchs dystrophy or PACE remain clear at 10 years. The risk for failure is greater for graft recipients with PACE and those with a history of glaucoma. Measurements of ECD and CT during the course of postkeratoplasty follow-up are associated with a risk for failure. However, even with very low ECD and high CT at 5 years, most corneas remain clear at 10 years.

Figure 1. Among those with a Surviving Graft at 5 Years, Graft Failure Rates over Time Stratified by 5 Year ECD and CT Values

In panel A, conditional on graft survival at 5.5 years (upper limit for the 5 year visit window), Kaplan-Meier cumulative probabilities of graft failure are shown for the <500, 500 to <1500, and ≥1,500 cells/mm² 5 year ECD groups. In panel B, conditional on graft survival at 5.5 years, Kaplan-Meier cumulative probabilities of graft failure are shown for the <600, 600 to <650, and ≥650 μm 5 year CT groups.