Washing with buffered vitamin C after corrosive chemical (sodium hypochlorite) exposure reduces ocular depth of injury.

Abstract

Chemical eye injuries occur in home, industrial, and military settings. The standard recommended treatment after exposure of the eyes to chemical toxins is washing with tap water for at least 15 min. An estimated 80 % of ocular toxins are associated with reactive oxygen species and/or extreme pH. Using food-source eyes and a commercially available test kit for depth of injury (IVD EIT^TM) that measures the depth of dead corneal keratocytes by fragmented DNA staining, washing the eye with a buffered vitamin C solution significantly reduced corneal keratocyte cell death and depth of injury compared to control. When eyes were washed (using a 500-mL eyewash bottle) for 15 min with water after exposure to 32 % sodium hypochlorite (chlorine bleach), the depth of injury was 59.6 ± 3.6 %, a level of damage predicted to cause extreme/permanent eye injury or even blindness in vivo (extreme or irreversible injury, GHS category 1), but washing with 0.2 % buffered vitamin C after bleach exposure reduced damage to13.8 ± 1.4 %, which is significantly less (P < 0.001) and predicted by the IVD EIT method to be reversible irritation (GHS category 2) that will heal within 21 days in vivo.