Purchase this article with an account.
DM Maurice, T Nagasaki, J Zhao; Nuclear Degeneration to the Keratocytes Near a Cornea Injury . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1711.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Keratocytes were found to die beneath an epithelial debridement in the mouse if the access of tears to the stroma was permitted. Further investigation has shown that, even in the absence of tears, nuclear deformation and degeneration is found in keratocytes in the stroma adjacent to an adequate mechanical injury to the epithelium. The purpose of these experiments is to isolate any direct mechanical component to this injury and understand the factors influencing it. Methods: The corneas were stained with a nuclear dye (DAPI) and examined, en face, by a fluorescence microscope and recorded digitally. The corneal epithelium was removed from a living or freshly killed mouse by either mechanical scraping with a blunt spatula or gentle lifting off the superficial cells by repeated touching with a gelatin-coated slide, and the stroma fixed immediately. In some live animals, the keratocyte nuclei were monitored with in vivo microscopy up to 8 hours. Where possible, the procedures were performed in human donor corneas. Results: In many corneas, debriding the cornea with a blunt blade lead to immediate nuclear changes in the most anterior keratocytes beneath the injured zone. The nuclei assumed an attenuated branched pattern but gave the overall impression of having been stretched by about 100 µm. In the living mouse, the nuclei did not show further changes over 4 hours, when the staining started to fade. If the epithelium was lifted off by repeated touching with a gelatin coated slide no nuclear deformation was found in the underlying keratocytes. However, it occurred if the bare stroma was subsequently rubbed with a blunt rod. Staining with the membrane impermeable dye ethidium homodimer-1 showed that the plasma membrane was compromised in the keratocytes with distorted nuclei. The nuclear changes occurred when the tissue had been previously fixed in 70% ethanol. Similar observations were made with human corneas. Conclusion: The nuclei of keratocytes beneath a scraped epithelium can be distorted and will degenerate. This appears to be a direct mechanical effect with no biochemical component.
This PDF is available to Subscribers Only