Advise against PMMA fillers
I am one of the leading experts in permanent filler complications. I would advise you to begin with reversible fillers with HA before moving forward with silicone or PMMA.
Well-performed Silikon-1000 injections may be considered for congenital under eye hollowing.
We have cared for many patients in their twenties with congenital lower eye lid grooves using Silikon-1000, an off-label filler for permanent results. Feel free to re-ask your question with photos for more specific advice.
Hope this helps you.