Very early endothelial cell loss after penetrating keratoplasty with organ-cultured corneas

Abstract

Aims After keratoplasty, postoperative endothelial cell loss is calculated between the eye bank endothelial cell density (ebECD) and the postoperative specular microscopy (SM). To elucidate the very early cell loss, always described after penetrating keratoplasty (PK), we designed two complementary studies. Methods (1) Clinical prospective study of 90 consecutive PKs (keratoconus, Fuchs' corneal dystrophy, lattice dystrophy, bullous keratopathy) with organ-cultured corneas and postoperative follow-up by SM at day 5 (D5), D15, month 1 (M1) and M3. This series provided a quantification of the difference between ebECD performed 2 days before graft and very early postoperative ECD. (2) Ten pairs of corneas with comparable ebECD in both corneas and same organ-culture (OC) duration were randomised: one cornea was grafted, and, at the same time, the viable ECD (vECD) of the other was measured after labelling with Hoechst/ethidium/calcein-AM. The relationship between vECD and very early postoperative ECD was studied.Results vECD at the time of graft did not differ from ECD 5 days after PK, with a difference of 39 (−356; 355) cells/mm 2 (median (10°; 90°percentile, p=0.799)), whereas a significant difference of 755 (359; 1146) cells/mm 2 , corresponding to 28% (95% CI 26 to 30) of cells, was measured between ebECD and ECD 5 days after PK ( p<0.001). Conclusions In OC, ebECD provided to surgeons significantly overestimate the number of viable ECs grafted to patients. The absence of difference between the vECD at D0 and ECD at D5 indicates that the very early endothelial cell loss is almost negligible in recipients.

Significant differences between specular microscopy and corneal bank endothelial cell counts – a pilot study

“…; Gauthier et al. ). The reasons for this endothelial cell count (ECD) decrease after corneal graft remain unclear.…”

“…Possible factors are surgical trauma, centrifuge cell migration and acute and subclinical chronic immune reactions (Gauthier et al. ). The chronic slow cell loss is supposed to be triggered mainly by a subclinical innate immune reaction, but the early decrease has not been fully explained (Gauthier et al.…”

“…The chronic slow cell loss is supposed to be triggered mainly by a subclinical innate immune reaction, but the early decrease has not been fully explained (Gauthier et al. ). The trauma caused by the trephination could be shown to be very limited (Moshirfar et al.…”

“…Recently, Gauthier et al. () described that endothelial cell count performed by corneal banks has a strong tendency to overestimate the number of endothelial cells shortly before transplantation. They suggested that specular microscopy should be performed as early as possible in the postoperative period to obtain a realistic endothelial cell count (Gauthier et al.…”

“…They suggested that specular microscopy should be performed as early as possible in the postoperative period to obtain a realistic endothelial cell count (Gauthier et al. ). Their findings basically challenge most existing clinical studies regarding endothelial cell loss and question the way we have been looking at this.…”