"Cannulas vs needles for lower eyelid filler injections"
Cannulas vs needles for lower eyelid filler injections.
Patients who are interested in lower eyelid filler injections frequently ask if I use a cannula or a needle to perform the injections. My answer is that after trying both techniques, I find that my results are much better when using a needle.
The idea behind a cannula makes a lot of sense. The filler is injected using a blunt tip instead of a sharp needle which may help limit bruising. This sounds great, but doesn’t work as well in my opinion.
When fillers are injected with a cannula, a single large puncture site is made with a large needle (as opposed to the very small needle used when fillers are injected directly). The blunt cannula is then introduced under the skin and moved to different locations around the eyelid where the filler is injected. Unfortunately it is very difficult to get filler into the all the right places and into the correct plane through a single entry site under the skin. Some areas fill well, but others may not. By using a small gauge needle to make multiple entry sites into the skin, filler can be placed at the correct location and at the correct depth to optimize the results.
An additional advantage is that the needle is short and rigid. I feel this is much safer than a long, flexible cannula which may bend and move into an unintended location when trying to inject far away from the puncture site. There is often significant bruising after lower eyelid filler injections, even when cannulas are used. The good news is that the results often last 1-2 years. Other doctors will have different opinions and different techniques that work best for them, but in my experience, a needle is preferable to a cannula for lower eyelid filler injections.