An improved method of intralamellar keratoplasty in rats

Intralamellar keratoplasty in inbred rats is a valuable method for the investigation of corneal allograft rejection. Present methods of intralamellar corneal grafting are tedious and time-consuming. In addition, induction of neovascularization, a prerequisite to inducing graft rejection, is variable. In an effort to overcome these problems, the authors have developed an improved method of intralamellar keratoplasty. Intralamellar pockets are formed by introducing a 30-g needle into the corneal stroma near the limbus. Approximately 10-25 microliters of lipopolysaccharide (LPS) (100 micrograms/ml) is injected into the stroma, forming a stromal bleb. This bleb is incised to form a pocket, resulting in the leakage of the injected liquid. The intralamellar pocket formation is completed by dissecting any remaining stromal fibers in the area of former bleb. Once the pocket has been formed, grafts of corneal tissue are inserted, and the incision is closed. This method of keratoplasty has the following advantages over previously reported methods: (1) It is more rapid and less tedious because the formation of the corneal bleb protects the anterior chamber from being invaded during the corneal incision; (2) It leads to a reproducible induction of neovascularization in every cornea so treated; (3) It results in a higher frequency of allograft rejection.