Establishment of a rabbit model of extrascleral extension of ocular melanoma.

PURPOSE

To establish an animal model of extrascleral extension of choroidal melanoma.

METHODS

Pigmented choroidal tumors were established in nine New Zealand albino rabbit eyes using B16F10 melanoma cell line. The sclerotomy site was not closed in the subgroup of six rabbits where extrascleral extension was desired. For the control group, the sclerotomy site was sutured with 8-0 nylon. Animals were treated with daily injections of cyclosporine and followed by serial fundus examinations, color Doppler imaging, and fundus photography. All tumor-bearing eyes were enucleated at the end of the follow-up period and examined for extrascleral extension.

RESULTS

Extrascleral extension of choroidal melanoma occurred in all six animals with open sclerotomy sites. No extrascleral extension was observed in the control group. Color Doppler imaging identified extrascleral extension which was confirmed on gross histology.

CONCLUSIONS

Our animal model of extrascleral extension of choroidal melanoma requires minimal surgery to establish, and is reproducible and easy to follow with standard diagnostic equipment.