Dacarbazine and Recombinant Interferon Alfa-2b in Treating Patients With Primary Uveal Melanoma With Genetic Imbalance

RATIONALE: Drugs used in chemotherapy, such as dacarbazine, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Recombinant interferon alfa-2b may interfere with the growth of tumor cells. Giving interferon alfa-2b together with dacarbazine may be an effective treatment for primary uveal melanoma. PURPOSE: This phase II trial is studying how well giving dacarbazine together with recombinant interferon alfa-2b works in treating patients with primary uveal melanoma with genetic imbalance.