Karma, also known as Renata, Karma Nera, Carma Rosenburg and Alexandra, was born in Slovakia as Renta Karskov and has worked in the adult industry in one way or another her whole adult life. She began working as a Mistress (professional dominatrix) and did a lot of hardcore films. Her specialty seemed to be anal sex and ass2mouth (cock straight from girls ass into her mouth).
In 1999, Karma tightened up her look a bit; getting her breasts lifted (but not enlarged), she slimmed down a bit, and gained some more muscle. It was at this time she broke out of the BDSM/fetish scene and more into the mainstream.
Karma stopped making movies in 2004 and it's rumored she has left the adult industry. New pictures are still being posted of her but that's meaningless in this industry as sites will take 1000's of pictures in one sitting and release them 100 at a time. She may be taking a break but I don't think she's gone