I have been injecting Botox for expression-related (i.e. movement-related, dynamic) horizontal "worry" lines ever since the early 1990s. It has long been known that if one injects within one-inch or so or less within the region above the eyebrows, then a brow drop (ptosis of the brows and lids) is a likely unwanted consequence. And this may be what happened in this particular case. Expert, experienced injectors are careful to respect the appropriate muscle anatomy in order to avoid such unwanted results as described here And although for the past ten years I prefer Dysport for most facial uses (since I find its benefits start a bit earlier, are a bit stronger, and last a month or two longer), Botox & Xeomin are each quite effective, as well. My guess is that the brow/lid heaviness relates to Dysport simply having been injected a bit too low on the forehead. As to whether a hyaluronic acid filler would be helpful, the answer depends upon whether or not there are static wrinkles present (i.e. wrinkles evident when the expression muscles are at rest). If so, then a hyaluronic acid filler can be quite helpful for elevating and smoothing the lines. Belotero Balance is my favorite for this in my NY practice, since it possesses little tendency to engenger the unwanted bluish/gray Tyndall Effect when injected superficially within the skin. (In my Israel satellite facility, where a far greater number of regulatory agency fillers are available, I typically opt for Toesyal Redensity II or Aliaxin FL for this purpose). Combining Botox and filler typically produces results that last considerably longer than the results of either treatment alone. Make sure that you are consulting with a board certified aesthetic physician and be certain to ask to see his/her before and after photos before agreeing to proceed. Best of luck.