Tear trough injections safety actual data - what are the risks?

I am trying to find information on the risk of blindness from injectables to treat treat trough hallows. Some say vague answers like "there's always a risk" and others claim it's extremely rare and that the tear trough area has never encountered blindness. Where can I find actual data on this? Many say to use a plastic surgeon but everywhere I go says nurses in office do it more often and DR costs more for less experience. I'm in Cleveland. Please advise.