Endothelial damage in monkeys after radial keratotomy performed with a diamond blade.

Anterior radial keratotomy was performed with a diamond blade in ten rhesus monkey eyes. Results were compared with those of a previous study in which a metal blade was used. Histologic assessment showed endothelial degeneration, but fewer edematous endothelial cells, than in the previous study. Specular microscopy demonstrated statistically significant endothelial cell losses (7.99%), when preoperative and three-month postoperative values were compared. Autoradiography showed little cell division in the endothelial cell layer. Cell loss seemed to be repaired mainly by the spreading of neighboring cells. Endothelial cell division is also limited in humans, and the cumulative loss of cells due to surgical trauma combined with continuous damage-related losses and later age-related reductions in cell numbers could produce corneal decompensation in some patients years after radial keratotomy.