1.Construction of a carbon dioxide laser-induced mouse corneal injury model and observation of corneal wound healing
Congling ZHOU ; Luguang JIAO ; Jiarui WANG ; Yixue YIN ; Zukang NIE ; Mengqi QIU ; Li ZHONG ; Zaifu YANG
Recent Advances in Ophthalmology 2024;44(10):769-773
Objective To construct a carbon dioxide(CO2)laser-induced corneal injury model in mice and observe the process of corneal wound healing.Methods Twenty eyes of ten C57BL/6J mice were divided into 4 groups.The cen-tral corneas in each group were irradiated by CO2 laser with a wavelength of 10.6 μm,spot diameter of 2 mm and power of 0.94 W.The exposure doses were 3.0 J·cm-2,4.5 J·cm-2,7.5 J·cm-2 and 10.5 J·cm-2,with corresponding expo-sure durations of 0.10 s,0.15 s,0.25 s and 0.35 s.Corneal injury severity was assessed using a slit lamp microscope,opti-cal coherence tomography and histopathological evaluation at 1 day after the exposure to determine the proper exposure dose for constructing a corneal injury model.Subsequently,the corneal injury model was constructed and the same meth-ods were used to monitor wound healing before,and 0 hours to 6 months after the exposure.Results No obvious corne-al injury was observed at an exposure dose of 3.0 J·cm-2.At an exposure dose of 4.5 J·cm-2,an off-white injury area appeared on the central cornea with loss of epithelium and endothelium.At an exposure dose of 7.5 J·cm-2 or 10.5 J·cm-2,the injury area became porcelain white,the cornea was thickened,and the iris was seen adhering to the margin of the cornea.Therefore,4.5 J·cm-2 CO2 laser was selected to construct a corneal injury model.At this exposure dose,the cornea swelled and thickened rapidly after injury,reached the maximum thickness 1 day after the exposure,and then grad-ually recovered,returning to normal by 14 days after the exposure.In the early stage(0 hours to 3 days after the expo-sure),the cornea showed shedding of injured epithelium and endothelium,migration of new epithelium and endothelium,and infiltration and regression of inflammatory cells.At the late stage(7 days to 6 months after the exposure),the cornea gradually returned to a normal physiological state,but some of the injured cornea exhibited stromal hyperplasia.Conclu-sion A CO2 laser with an exposure dose of 4.5 J·cm-2 can be used to construct a corneal injury model in mice.The a-cute phase of corneal injury primarily occurs within 3 days after the exposure.The cornea tends to restore its original physi-ological structure,but the corneal transparency cannot return to a normal state.