To ensure this is not a GPU or VGC issue you could connect to an external monitor to ensure you do not observe the same thing.
If you saw the same shadow or dim edges that would indicate it is the chip, not the internal display chain. If the problem is the chip you'd need a new logic board or the current board "re-flowed" or possibly the GPU replaced (they are soldered to the logic board). This would not be a DIY project. There are services on e-bay that offer Graphics/logic board repair. (No I can't recommend anyone).
Replacing the inverter would be easier and cheaper than replacing the display, and replacing the entire display easier than trying to replace just the backlight.