Had dermal filler in tear troughs yesterday. a few hrs after injection, started getting mod-severe edema under left eye. what happened/what to do?

Allergy or infection: If the reaction started hours after the procedure it is most likely an allergic reaction. You should go back to the doctor that did the procedure so he can treat that for you. Either an allergic reaction or an infection can be a serious problem.

Go to Your doctor: This could represent a site injection reaction, minor bleeding or an immune reaction (allergic reaction) at the site of injection. More seriously, this could represent an early infection. Your doctor should check this out.

Can Be Normal: The tear troughs are a very tricky place for dermal filler, so only a trained injector should be doing it. It is completely normal to get some swelling and minor bruising to this area after filler injections. I would recommend cold compresses to the area for the next day or too. I only inject Restylane (dermal fillers) to this area because other fillers like juvederm have a 6 times greater ability to swell.

Swelling/filler: Swelling after injections is not unheard off. Follow your injectors post procedure instructions which may include using a cool compress.