Is it possible for Restylane to cause bigger pores?

It is most likely that transient edema from the injection has temporarily enlarged your pores. This should self correct itself.

If the skin is stretched or swollen, the pores can appear larger.  This should go away as the swelling from the restylane subsides.

Depending on the amount of Restylane used and area such as th cheeks it can definitely appear they the skin texture has changed or the pores have enlarged. This should be temporary unless too much product was placed improperly. I prefer Sculptra or Voluma for this mid face area since you will usually not have this effect. Please consult a board certified dermatologist Eitan experience with facial injections for the best cosmetic results.