A new technique for implantation of tissue culture melanoma cells in a murine model of metastatic ocular melanoma

The aim of this study was to compare the transcorneal and transconjunctival techniques for the implantation of intraocular melanoma cells and development of metastasis in a murine model. Groups of C57BL/6 mice were given either transconjunctival or transcorneal inoculations of 2.5 x 10(5)/2.5 microl tissue culture B16-LS9 melanoma cells into the intraocular posterior compartment (PC). The eyes were enucleated at 4-11 days post-inoculation and histologically examined. The mice were sacrificed 14 days after enucleation and necropsies were performed with histological evaluation for visceral metastases. Intraocular and extraocular tumour growth was present in all of the eyes inoculated via the transconjunctival route. Pulmonary metastases were found in this group if the eye was enucleated 7 or more days post-inoculation. The melanoma remained confined to the inside of the eye in the transcorneal group until day 7. Haematogenous metastases to the lung and liver developed from the intraocular melanoma in this group. Transcorneal inoculation of tissue culture melanoma cells into the murine PC provides a useful animal model for visceral metastasis of ocular melanoma.