Is there any way for tear trough fillers like Restylane to cause floaters in the eyes or an increase of floaters?

Floaters are usually an age-related phenomena. Certain diseases of the eye, and retina can also cause floaters. Unless you have developed an infection or the filler has caused pressure on your eyeball, it is unlikely for floaters to result from this type of treatment. Good luck!
Jeff Rapaport MD FAAD

Floaters form inside the eye as the jelly (vitreous) in the eye undergoes changes.  The aging process is the most common culprit, but they can form after hard, jerky movements of the head (as in bungee jumping or after a car accident), trauma to the head/eye, or surgery inside the eye (such as cataract surgery).  Unless there was some serious pressure over your eye after the Restylane, I do not know of any reason you should develop floaters after Restylane.
Any hyaluronic acid filler (such as Juvederm or Restylane) injected in the tear trough has the potential to cause BLINDNESS by directly or indirectly causing an occlusion of the blood vessels supply to and from the eyeball.  We call this a vascular occlusion.  It is not associated with floaters.