Sclerotherapy under the eyes - side effect?

I prefer a selective microphlebectomy in the area vs. this procedure. An examination would be important to assess the cause of the bulging. Best, Dr. KaramanoukianLos Angeles

Yes, it is normal to have some swelling after your treatment and it should resolve in a few weeks. Cold compresses may help in addition to venus legacy treatments. Best, Dr. Emer

Sclerotherapy for the under eye should be used very very selectively as it may leave permanent hyperpigmentation and in some cases, swelling.Anyways, you need some topicals to reduce hyperpigmentation. 
You need to use some adjunctive measures after sclerotherapy to reduce post inflammatory hyperpigmentation. it is those that don't follow such instructions immediately following sclerotherapy, starting on day1 (next day) that seem to get retained hyperpigmentation. I recommend 2 creams: Scleroquin plus and Sclerovase and also Scler-X supplement to reduce post inflammatory hyperpigmentation (see link below) as well as compression stockings for at least 2 weeks.
H Karamanoukian MD FCS
certified vein specialist from ABVLM and double board certified surgeon

The area under the eye is very difficult to treat with sclerotherapy.  Not just with the injection technique but the area is prone to excessive swelling and very vascular.  Tissue trauma with sclerotherapy can cause out of balance swelling in the area.  Ice packs/pads to the area should significantly improve the swelling as well as Arnica pellets or cream.   The swelling should quiet down over a few months.  

You may have some swelling which will resolve over the next few days to weeks.  Ice often helps with this.  We usually do not like to do sclerotherapy under the eyes and often choose other treatments like vein gogh or laser.  The sclerotherapy will help the veins go away but it may take a little while for the swelling to abate

What you seem to be describing is post sclerotherapy swelling.  This should improve over 2 to 6 weeks post treatment. Ice to the area may help and you should follow up with your treating physician.