Effect of Age and Keratoplasty on the Postnatal Development of Feline Corneal Endothelium

Abstract

Unilateral autologous rotational penetrating keratoplasties were performed on 10 4-week-old kittens. Three eyes were lost to glaucoma secondary to anterior synechiae formation, four eyes were examined histologically 2 weeks to 1 month postoperatively, and the three remaining eyes were examined serially for 9 months by slit lamp observation, specular microscopy, and pachometry. Contralateral unoperated control eyes demonstrated a rapid decline in endothelial cell density during the first 8 weeks of life (6000 cells/mm2 to 3800 cells/mm2), a change which correlated with the growth of the cornea to its adult size. Thereafter, the endothelial density declined more gradually (2800 cells/mm2 at 6 months). Transplants exhibited a 50% endothelial cell loss 2 weeks postoperatively that related to the keratoplasty procedure, and the endothelial cell density subsequently declined gradually with age. Corneal thickness comparisons of unoperated and postkeratoplasty eyes suggests that the endothelium of the infant kitten has less functional reserve than the adult endothelium. Corneal endothelial cell counts made from infant and adult dogs, rabbits, and humans indicate that the high postnatal endothelial cell density observed in the cat also occurs in other mammalian species.