Can undereye fillers cause herpetic keratitis?

It’s possible that the injection from Restylane around the eye triggered your symptoms. If they do not resolve, make sure you see your doctor for proper treatment right away.

The herpes virus does not go away when it is not active, but rather it remains in the nerves and may be reactivated by stress or other factors as you mentioned. Many practitioners will pre-treat patients with a known history of oral cold sores (oral herpes) prior to filler in the lip area because the stress of the procedure can reactivate the virus. The same may be true for ocular herpes given a procedure around the eye. I would suggest that you seek the proper care with your local ophthalmologist to treat your herpes keratitis as soon as possible. I hope this helps. 

It is possible that the filler caused the herpetic outbreak. It didn't introduce the virus but could've awoken the virus which was dormant in the infraorbital nerve or surrounding nerves. The trauma of the needle or cannula to the nerve could've been the inciting factor. I will give preventative doses of valcyclovir in cases of prior herpes zoster or cold sores during filler injections in most cases.