To explore the long-term influence of donor central graft thickness (CGT) and donor graft size on corneal endothelial cell density (ECD) after Descemet stripping automated endothelial keratoplasty (DSAEK).

An observational case series study was conducted.One hundred and forty-four eyes of 134 patients who underwent DSAEK in Peking University Third Hospital from January 2013 to December 2017 with at least 24-month follow-up were enrolled.Preoperative donor ECD was evaluated by specular microscopy, and ECD was determined by in vivo confocal microscopy at 1, 3, 6, 12, and 24 months postoperatively.Donor CGT was measured by anterior segment optical coherence tomography.According to the 3-month postoperative donor CGT, the subjects were divided into thinner graft group (45 eyes with CGT<100 μm), medium-thick graft group (66 eyes with CGT≥100-<150 μm) and thicker graft group (33 eyes with CGT≥150 μm). According to the donor trephination size, the subjects were divided into smaller graft group (31 eyes with trephination size≥7-<8 mm) and larger graft group (113 eyes with trephination size≥8-<9 mm). The changes of the donor CGT and corneal endothelial cell loss rate were compared at different time points after surgery.The relationships between 24-month postoperative ECD and donor ECD, donor graft size and donor CGT were analyzed.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Peking University Third Hospital (No.IRB00006761-2008025). Written informed consent was obtained from each subject prior to any medical examination.

The donor CGT was 129.0 (90.8, 160.8), 115.5 (93.0, 146.0), 115.5 (89.0, 151.0), 112.5 (94.3, 146.8) and 114.0 (89.0, 144.5) μm at 1, 3, 6, 12 and 24 months after surgery, showing a statistically significant difference (H=37.369, P<0.001). There was a statistically significant difference between 1-month and 3-month postoperative CGT (P<0.001). There was no statistically significant difference in the endothelial cell loss rate among the three different donor CGT groups and between the two different donor graft size groups at any postoperative time points (all at P>0.05). Spearman correlation analysis showed that the 24-month postoperative ECD was strongly positively correlated with the preoperative donor ECD(r_s=0.783, P<0.001), which was not associated with donor graft size and donor CGT (r_s=0.141, P=0.093; r_s=-0.044, P=0.600).

Larger postoperative ECD is correlated with larger preoperative ECD of donor graft.Lower long-term corneal endothelial cell loss rate after DSAEK is associated with thinner and larger diameter of donor graft.

Cornea; Endothelial cells; Corneal endothelial cell loss; Corneal endothelial cell density; Descemet stripping automated endothelial keratoplasty; Donor graft thickness; Donor graft size