You can use any med that treats bacterial infections. Erythomycin or Furan-2 are good. Also try the following, To reduce swelling, you can treatthe fish with Epsom salt. Add between one and three teaspoons of Epsom salt for every five gallons of water in the treatment tank. This should help reduce swelling over the course of the next several days. As long as the water conditions are stable, corneal damage should heal as well.