Your Win Condition
This is a very annoying matchup. You are not really killable at any point in the lane. Your goal is to be more useful in the team fight scenario.
General Strategy
I like running Fleet Footwork, Doran's Shield, and Second Wind against Karma. She has too much shielding, movement speed, and healing to burst down.
Trading Patterns
Karma's W-R (Empowered Focused Resolve) heals her for 70% of HP plus AP scaling, which is a massive self-heal. She can stun you through your E animation.
Wave Management
Their Win Condition
Karma wins by utilizing her high shielding, movement speed, and healing (especially R-W) to prevent your burst.

