In mild to moderate burns, the eye is hyperemic and may display conjunctival chemosis, eyelid edema, first degree burns to the skin, and cells and flare in the anterior chamber. Corneal findings may range from diffuse superficial punctate keratopathy to focal epithelial erosion with mild stromal haze. When the chemical injury is severe, the eye is not red but appears white due to ischemia of the conjunctival vessels. Chemosis of the lids and conjunctiva is evident, and surrounding facial areas may demonstrate second or third degree burns. Corneal findings include total epithelial erosion with edema and dense stromal hazing, and sometimes complete opacification.
Acids tend to bind with tissue proteins and coagulate the surface epithelium.
This bars further penetration so acid burns are typically confined to superficial tissues. Most commonly, acid burns to the eye result from exploded car batteries, which contain sulfuric acid. Alkaline burns occur more frequently and are generally more severe than acid burns. These solutions destroy the cell structure not only of the epithelium but also of the stroma and endothelium. While acids create an initial burn and then cease, alkalis may continue to penetrate the cornea long after the initial trauma.