Donor age and corneal endothelial cell loss 5 years after successful corneal transplantation. Specular microscopy ancillary study results

Abstract

Objective: To determine whether endothelial cell loss 5 years after successful corneal transplantation is related to the age of the donor.

Design: Multicenter, prospective, double-masked clinical trial.

Participants: Three hundred forty-seven subjects participating in the Cornea Donor Study who had not experienced graft failure 5 years after corneal transplantation for a moderate-risk condition (principally Fuchs' dystrophy or pseudophakic corneal edema).

Testing: Specular microscopic images of donor corneas obtained before surgery and postoperatively at 6 months, 12 months, and then annually through 5 years were submitted to a central reading center to measure endothelial cell density (ECD).

Main outcome measure: Endothelial cell density at 5 years.

Results: At 5 years, there was a substantial decrease in ECD from baseline for all donor ages. Subjects who received a cornea from a donor 12 to 65 years old experienced a median cell loss of 69% in the study eye, resulting in a 5-year median ECD of 824 cells/mm(2) (interquartile range, 613-1342), whereas subjects who received a cornea from a donor 66 to 75 years old experienced a cell loss of 75%, resulting in a median 5-year ECD of 654 cells/mm(2) (interquartile range, 538-986) (P [adjusted for baseline ECD] = 0.04). Statistically, there was a weak negative association between ECD and donor age analyzed as a continuous variable (r [adjusted for baseline ECD] = -0.19; 95% confidence interval, -0.29 to -0.08).

Conclusions: Endothelial cell loss is substantial in the 5 years after corneal transplantation. There is a slight association between cell loss and donor age. This finding emphasizes the importance of longer-term follow-up of this cohort to determine if this relationship affects graft survival.

Figure 1

Number of subjects assigned a cornea by each year of donor age. ECD = endothelial cell density (cells/mm²).

Figure 2

Endothelial cell density at 5 years versus baseline for subjects with a successful graft at 5 years (N = 347). Spearman correlation coefficient (95% confidence interval) = 0.27 (0.17–0.36).

Figure 3

Endothelial cell density (cells/mm²) over time for subjects with a successful graft at 5 years. In the box plots, horizontal lines denote medians, and the bottom and top of the boxes represent the 25th and 75th percentiles.

Figure 4

Five-year endothelial cell density (ECD) by donor age for subjects with a successful graft at 5 years (N = 347). Spearman correlation coefficient (95% confidence interval) = −0.23 (−0.33 to −0.13); partial Spearman correlation coefficient adjusted for baseline ECD = −0.19 (−0.29 to −0.08).

Figure 5

Percent change in endothelial cell density (ECD) from baseline to 5 years by donor age for subjects with a successful graft at 5 years (N = 347). Spearman correlation coefficient (95% confidence interval) = −0.20 (−0.30 to −0.09); partial Spearman correlation coefficient adjusted for baseline ECD (95% CI) = −0.19 (−0.29, −0.08).

Figure 6

Percent change in endothelial cell density from baseline to 5 years in donor age groups for subjects with a successful graft at 5 years. In the box plots, black dots denote mean values, horizontal lines are medians, and the bottom and top of the boxes represent the 25th and 75th percentiles.