A federal judge on Tuesday issued a permanent injunction against U.S. Stem Cell, a Sunrise, Fla., clinic accused of blinding three patients by injecting a fat extract into their eyes.

The company is just one of hundreds of businesses that have sprung up around the country offering to treat a wide array of illnesses with products they say contain stem cells that have healing and regenerative properties. Medical experts say there is no proof that such treatments work.

Many of those clinics, like U.S. Stem Cell, use extracts from fat. Others use patients’ own bone marrow, and some use cord blood or other birth tissue like amniotic membranes.

Although the injunction applies only to one company, it is widely seen as a warning to others that perform similar procedures.