Keratocyte Density and Recovery of Subbasal Nerves After Penetrating Keratoplasty and in Late Endothelial Failure

Abstract

To determine central keratocyte and subbasal nerve densities in clear and failed grafts after penetrating keratoplasty. Clear grafts and grafts with late endothelial failure (LEF) were examined using confocal microscopy 1 to 31 years after penetrating keratoplasty. Keratocyte density, number of keratocytes in a full-thickness column of stroma, and subbasal nerve density were determined from images. Comparisons were made with normal corneas. The mean +/- SD keratocyte density in clear grafts (22 101 +/- 3799 cells/mm(3)) was lower than that in normal corneas (26 610 +/- 3683 cells/mm(3); P < .001) but did not differ from that in grafts with LEF (21 268 +/- 3298 cells/mm(3); P = .47). The mean +/- SD number of keratocytes in clear grafts (10 325 +/- 1708 cells) was lower than that in normal corneas (11 466 +/- 1503 cells; P < .001) but did not differ from that in grafts with LEF (10 778 +/- 1760 cells; P = .39). Median subbasal nerve density in clear grafts (150 microm/mm(2)) was lower than that in normal corneas (7025 microm/mm(2); P < .001), and nerve recovery correlated with time after surgery (r = 0.36; P < .001). Keratocyte density and number are decreased in penetrating grafts compared with normal corneas. Subbasal nerve density does not recover to normal through 3 decades.