Abstract
Abstract: :
Purpose: We evaluated the type of injury caused by individual ingredients found in the most common OTC firework’s products, and compared this to the injury that might be caused by deposition of the actual firework’s composition in an injury model with varying levels of concentration of product in amounts theoretically, and clinically, found in actual injuries to the human eye. Methods: Pigmented rabbits were used in which one eye served as a control. Aliquots of 1/1000, 2/1000, and 3/1000 (corrected to the percentage of chemical ingredient in the specific firework product used) of pure potassium nitrate, sulfur, blackpowder (comprised of 75% potassium nitrate, 15% charcoal, and 10%sulfur), copper oxide, dinitrotoluene were injected using a 30 gauge needle under direct microscopic observation by an experienced vitreoretinal surgeon into the vitreous, the anterior chamber, cornea, and sub-sclera. This was compared to similar concentrations of reactants obtained from small bottle rockets, sparklers, and fire-crackers injected in a similar manner. At 1 and 3 hours after injection eyes were sectioned after fixation in 10% formalin, and processed for light and electron microscopy in a routine manner, and examined histopathologically. The effects of velocity and temperature were not specifically controlled nor studied. Results: Definite chemical injury to the layers of the retina could be seen on both light and electron microscopy in the groups that received intravitreal injections of both pure chemical, as well as final reactant product. Otherwise, only local tissue effects were noted around the injection sites of chemical(s) into the anterior chamber, cornea and sub-sclera locations. Initially a poymorphonuclear cellular reaction was noted, the severity increasing as the concentration of either pure or mixed reactants increased. Nitrates, sulfur, and blackpowder were noted to cause lens opacities in eyes in which the reactant was injected into the anterior chamber. Conclusions: Local tissue reactions predominate. Sulfur, nitrate, and blackpowder cause lens opacities, cataract, and focal chorioretinitis. The toxicity of firework’s-induced chemical injury to the eye appears to depend on particle size, location, concentration, and type of reactant. These all play important roles in defining the nature and extent of injury and this is in large part determined by the composition and construction of the firework device in this rabbit model of chemical injury to the eye.
Keywords: trauma • pathology: experimental • drug toxicity/drug effects