Is it possible that HA filler around eye region results can last for 6-10 years due to scar tissue and other reasons?

Hyaluronic acid fillers do not in any way create collagen or scar tissue in the area where they have been injected. What happens is that the body breaks down the filler differently in the lower eyelid area unlike elsewhere. It is the filler itself that can last indefinitely in great many people, but that comes with a warning. Because of the thinness of the tissues near the eye the filler it tends to shift towards the nose creating a bag like appearance which is very difficult to get rid of unless an intervention is performed. It is My strong feeling over the last 26 years of using such fillers thant hyaluronic acid fillers should not be used on the lower eyelid area in absolutely anyone. Instead, fat grafting should be performed as it produces natural and permanent results. Fat grafting can be used anywhere on the face and body with an incredible amount of safety and excellent and reproducible results. I hope this helps and good luck from your city plastic surgery

Though some patients get a little more or less longevity from filler treatments, most last 1 to 2 years depending on the filler selected. HA filler effects lasting 6-10 years sounds great, but is not likely.