Animal study reveals benefits of retrobulbar hyaluronidase for filler-induced blindness

This animal study assessed the effectiveness of retrobulbar hyaluronidase treatment for blindness resulting from soft-tissue filler injection.

Study design

The authors administered retrobulbar hyaluronidase to 4 New Zealand white rabbits at 5 or 10 minutes after hyaluronic acid-associated vascular occlusion. These treated rabbits were compared with an occluded control that did not receive hyaluronidase. Fundus photography was performed before and immediately after filler injection, and immediately after hyaluronidase injection. Electroretinography was performed 60 minutes after filler injection.

Outcomes

Two rabbits underwent enzyme injection 5 minutes after filler injection while the other 2 rabbits underwent enzyme injection 10 minutes after filler injection. Three of four eyes with a completely occluded retinal artery showed improved perfusion by fundus photography and electroretinography. Both control eyes continued to demonstrate occlusion 1 hour after filler injection.

Limitations

New Zealand rabbits are not an ideal model for this study, as the choroid is translucent. The study figures seem to indicate that the rabbits only sustained branch retinal artery occlusions, not central or ophthalmic occlusions. The experimental design has significant flaws.

Clinical significance

This study offers hope that retrobulbar hyaluronidase could improve hyaluronic acid filler-associated blindness; however, the findings contradict previous studies. Additional studies are needed to understand the potential benefits of retrobulbar hyaluronidase for treatment of hyaluronic acid filler induced blindness.