Why did I get a bag after tear trough filler with micro cannula? (Photo)

I dont see enough excess fat to warrant eyelid surgery. There is very little margin for error when injecting the under eye area. My personal opinion is that I get much better results when using needles compared to using a microcannula. A microcannula needs to be inserted under the skin through a single puncture wound and then guided to different positions in the eyelid. In my experience it is very difficult to get the cannula to the right place and right depth throughout the lower eyelid through this single entry site.I suspect other doctors will have different opinions on this topic. My recommendation is to find a doctor who has a lot of experience treating the under eye area and then go with whatever method he or she recommends. 

Difficult to say from the pictures.  The lighting is different and left and right look different.
Cannula is generally seen as safer as less likely to inject into a blood vessel.  But this does depend on the injector.
You seem a bit young to have eyelid surgery.  
I would suggest seeing your injector again and discus your concerns and come up with a plan.
Time is also a good predictor, don't rush to have more filler and other treatments.

This may be due to injector technique, but keep in mind a combination approach is needed to get improvement under the eyes. Fillers, lasers, and microneedling/PRP can improve under the eyes. My patients try to get non surgical treatments to avoid surgery. We use PRP and stem cells there often. I suggest consulting with an expert to develop a treatment plan best suited for your short and long term goals. Best, Dr. Emer

It appears you have fat bag under eye. You may fair better with transconjunctival lower blepharoplasty with fat redraping but I need to examine you to better help you.

I suspect this is related to injector experience and technique. I use a blunt tip microcannula for most of my tear trough filler treatments. The correct filler needs to be used and it needs to be placed deep to prevent lumps and bumps. A microcannula is safer when it comes to the undereyes then a needle and it also leads to less bruising and swelling.

Injector technique and skill is the most important factor in ensuring an excellent result after filler injection.  Most of the time I prefer to use a microcannula under the eyes because it minimizes the risk of bruising or other side effects.  In certain situations, needles can be more precise, but in my hands they are rarely necessary for injection under the eyes.  The key with using a microcannula is to be patient, not rush the injections and really pay attention to the treatment areas during the injection. Regards,Dr. Ort

Heiddy,Injector technique is at the crux of good versus great results from tear trough filling. There is a role for both micro-cannula and needles depending on the severity of the under eye hallow seen. If the tear trough was injected recently, a bit of swelling is expected from the act of filler placement and the filler's ability to absorb water (usually settles within 2 weeks.) Another consideration is that you are seeing a fat pocket that was not entirely camouflaged, but this would be hard to say with certainty without seeing a before picture (less likely the case.) At times, if not enough filler is used, this can also cause contour irregularities. I would consult again with your injector to determine if massaging or any other techniques are recommended (injector specific.)Hope this helps!Hardik Doshi, M.D.