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Publisher Summary This chapter describes the rabbit intrastromal injection model of Pseudomonas keratitis. Typical chemotherapy experiments employ Young New Zealand white rabbits, weighing 2–3 kg. For membranectomies, a hand-held electric cauterizer is required for limiting bleeding during this surgical procedure. At the termination of the experiment, a scalpel with a no. 10 blade, surgical scissors, a hemostat, and forceps are required for the removal of the corneas from sacrificed rabbits. For general anesthesia, rabbits are injected intramuscularly with a mixture of ketamine (50 mg/kg) and xylazine (10 mg/kg). Immediately prior to intrastromal injection or membranectomy, the eye is anesthetized by topical administration of two drops of proparacaine. As the injection of ketamine and xylazine can effect iritis and possibly other types of ocular inflammation, slit-lamp examination (SLE) is best performed prior to the administration of anesthesia. The nictitating membrane should be removed at least three days prior to the initiation of infection. This surgery involves the application of general and local anesthesia followed by the cutting of the membrane. Every strain of bacteria used for bacterial keratitis is characterized in terms of its growth characteristics both in vitro and in vivo. The infection process does not induce stress in the rabbit until the SLE score exceeds a value of 20. The seven parameters graded are conjunctival chemosis (edema), conjunctival injection (redness), corneal edema, corneal infiltrate, fibrin accumulation in the anterior chamber, hypopyon formation, and iritis. The SLE for a maximally inflamed eye is 28, but this is a theoretical value and eyes should not be allowed to advance significantly beyond a score of 20. |
