Antibody response following implantation of xenogenic lenticules.

Rabbits underwent implantation of either lyophilized or fresh porcine lenticules into the central or peripheral cornea. All animals were followed for up to four months by slit-lamp examination and macrophotography to determine implant rejection. Serum antibody levels to soluble porcine cornea extract were determined by an enzyme-linked immunosorbant assay. Only those animals receiving lenticules into the peripheral cornea experienced a rejection and developed an antibody response to the porcine cornea extract. The production of antibody preceded the appearance of vascularization of the implanted lenticules. Thus, the site of lenticule implantation, not the type of tissue preparation, determined the outcome of the graft.

Keratophakia with lyophilized cornea lathed at room temperature: new techniques and experimental surgical results.

A modified method of prelathing lyophilized corneal tissue at room temperature for refractive keratoplasty is described. This method allows perfect centration of a lyophilized corneal button on the plastic base and thus more accurate lathing. Keratophakia was performed with lenticules prepared in this fashion on a series of eight cats which were followed for 30 weeks postoperatively. All lenticules were clear ten weeks following surgery and the final optical correction obtained varied +/- 2.5 D from the intended correction.

Evaluation of sources of variation on the accuracy and reproducibility of microkeratome sections with the modified artificial anterior chamber.

A study was carried out to evaluate effects of various sources of variation on the accuracy and reproducibility of the modified artificial chamber in obtaining lamellar sections from rabbit cornea. Sources of variation included a) measurement error, inter-cornea and inter-session variation, b) length of storage time M-K medium, and c) choice of preselected values of thickness and diameter. The findings indicated tha a) measurement error, inter-cornea, and inter-session variations were of nominal magnitude; b) the length of storage time up to 10 days did not effect the precision of the procedure; c) the precision of diameter determinations did not depend on the preselected value of the diameter; d) the precision of thickness determinations did depend on preselected parameter values; and e) parameter values tended to be underestimated. Regression equations therefore are provided to adjust for the underestimation of thickness and diameter. Based on these findings, it was concluded that the modified artificial anterior chamber is adequate for use in experimental refractive keratoplasty since it provides adequate diamter values and is reproducible.