Photorefractive keratectomy (PRK) with a 193-nm excimer laser has been shown not to destroy endothelial cells in vivo. However, this laser could damage endo-thelial cell metabolism, and result in damage over a longer term. In this paper, a comparison between the number and shape of corneal endothelial cells has been performed in 25 patients before and 6 months after PRK. These patients underwent treatment with myopic correction ranging from 2.5 to 17 dpt and with an estimated corneal thinning ranging from 25 to 170 µm. No significant changes in the number (p = 0.167) and shape (p = 0.075) of endothelial cells have been found. These results show that there are no long-term damages after PRK even in severely myopic eyes.