Are airbags a risk for patients after radial keratotomy?

Recently, some investigators have expressed concern about the impaired integrity and decreased tensile strength of the cornea following radial keratotomy (RK) and wound healing, because of pathological findings in human and animal corneas.1-3Corneal tensile strength in eyes following RK has been evaluated in animal models. It has been reported that rabbit corneas require 54% less energy for rupture following RK than human control corneas over a 90 day period, and 98% of operated eyes rupture along one or more corneal incisions with or without extension into the sclera.4 In a histopathological study, incomplete healing 2 years after RK has been reported.5 In contrast, there was no significant difference in tensile strength between RK corneal strips and control strips from human cadaver eyes, indicating that the increase in susceptibility to rupture due to RK may be hard to predict and may depend on factors such as the size of the epithelial plug and the strength of the wound collagen.2 However, after the epithelial plugs are replaced with collagen, there is no assurance that the tensile strength of the cornea will be more than 50% of the preoperative value, since the only barrier to globe rupture from direct external forces and internal forces of acutely raised intraocular pressure at the time of impact is the 0.02 to 0.05 mm of unincised corneal tissue, epithelial plugs, and irregular …