Ocular melanoma is a rare type of cancer that normally occurs in about 6 in every 1 million individuals. But according to scientists, more than four dozen people around Huntersville, North Carolina, and Auburn, Alabama, have been diagnosed with the condition, and at least four have died, reports CNN.

And although researchers have also learned that at least 38 of the patients attended Auburn University between 1983 and 2001, they are not yet defining it as a cluster.

The Centers for Disease Control and Prevention defines a cluster as “an aggregation of cases grouped in place and time that are suspected to be greater than the number expected, even though the expected number may not be known.”

Ocular melanoma is different from skin melanoma. This aggressive and lethal cancer can quickly spread to other parts of the body, especially the liver. (About 50 percent of cases metastasize, or spread, to this organ.) Symptoms of ocular melanoma include blurry vision, spots in the visual field and vision loss.

“There’s really nothing officially FDA-approved to treat eye melanoma,” said Marlana Orloff, an oncologist at the Jefferson University Hospital in Philadelphia, who is treating a number of the Alabama patients.

While scientists have yet to find a cure for this eye cancer, many people have turned to radiation therapy and surgery to help extend their life span and quality of life. But sometimes, the removal of the eye is necessary.

“We need the funding for the research to figure out what possibly could be the environmental cause,” Orloff said. “There must be some link, and if we can find that link, we’re that much closer to finding a cure and preventing people from continuing to get this.”

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