A Combination Drug Treatment Against Ocular Sulfur Mustard Injury

Abstract

The eye is considered to be one of the most sensitive organs to sulfur mustard [bis(2‐chloroethyl) sulfide (SM)], with injuries ranging from mild conjunctivitis to advanced corneal disease. Even mild ocular involvement from sulfur mustard exposure can result in both physical and psychological incapacitation. In this study we explored the use of Food and Drug Administration (FDA) approved medications (prednisolone acetate ophthalmic suspension, triamcinolone, and cefazolin) as ocular treatments for sulfur mustard injury. Female New Zealand White rabbits were divided into a SM positive control group (n = 8) and a single treatment group (n = 7). At 10, 20, 30, 60, 90, and 120 min after SM exposure, two drops of prednisolone acetate ophthalmic suspension was administered to each treatment group rabbit while the control group received saline drops. At 120 min after SM exposure, each treatment group animal received a single 1.0 mL sub‐Tenon's injection containing 20 mg triamcinolone and 50 mg cefazolin. Control group rabbits did not receive an injection. Rabbits were observed for a total of 16 weeks after SM exposure. Corneal thickness, corneal stromal injury, neovascularization (NV), eyelid notching, and chemosis were recorded weekly for 6 consecutive weeks and on week 16 after exposure. The SM treatment group at weeks 2, 3, and 4 had a significantly lower index value for corneal thickness than the SM positive control group. For corneal stromal injury, NV, eyelid notching, and chemosis, significant evidence of a protective effect due to treatment was seen at weeks 4, 5, and 6. In addition, corneal stromal injury was reduced at weeks 2 and 3 and notching at week 2. By week 3, all SM positive control animals developed NV in contrast to 1 of 7 treatment animals. By week 6 all positive control animals still exhibited NV compared to 2 of 7 treatment animals. These data suggest that prednisolone acetate suspension dosed for the first 2 h after SM exposure followed by a single sub‐Tenon's injection of a triamcinolone/cefazolin combination is effective in treating the early stages of corneal injury from SM exposure.