Long-term morphologic changes in the endothelium of transplanted corneas
M. Matsuda and W. M. Bourne
In a group of 17 patients, we studied the endothelial morphology and
thickness of the central cornea yearly for five years after penetrating
keratoplasty. The endothelial photographs were analyzed with a computerized
digitizer to determine the area and shape of individual cells. The
endothelial cell density decreased rapidly during the first two years
postoperatively (59.4%), after which cell loss occurred at a considerably
slower rate (3.5% of the preoperative cell count per year). During the
observation period, the coefficient of variation in cell area stayed
relatively constant (30%), implying that individual cells enlarge
proportionally to their areas when spreading. The percentage of hexagonal
cells and figure coefficient for the donor corneas were 60.5% and 0.8774,
respectively. When the corneal thickness returned to normal two months
after surgery, the endothelium showed a significant decrease in both
measurements (48.2% and 0.8708, respectively), indicating a definite
disruption of the normal hexagonal pattern. Between two months and two
years postoperatively, both measurements gradually returned to normal.
These results suggest that termination of endothelial cell loss from the
central graft might be closely associated with the reestablishment of the
normal hexagonal cellular pattern.
