An In Vitro Model Assessing the Penetration of Hyaluronidase through Optic Nerve Dura for Management of Hyaluronic Acid Facial Filler Embolism.

BACKGROUND

Blindness from ophthalmic or central retinal artery embolism is one of the most devastating complications of cosmetic filler facial injections. A proposed therapy to mitigate visual loss is prompt retrobulbar injection of hyaluronidase into the retrobulbar space. Despite Zhu et al. showing a lack of evidence and very limited published literature for reversing visual loss with this intervention, it is still widely accepted as a treatment for filler-related emboli. The purpose of this study was to evaluate the penetration of hyaluronidase through optic nerve dura using an in vitro model.

METHODS

At study conclusion, five 1-cm-long segments of fresh optic nerve were obtained and injected with highly crosslinked hyaluronic acid filler, then ligated on both ends in a watertight fashion. The sections were immersed in three concentrations of hyaluronidase solution for 24 hours. Histopathologic examination of the specimen was performed to assess the presence of filler.

RESULTS

The optic nerve sections were 1.1 cm (range, 0.8 to 1.2 cm). Three were immersed in 20 ml of 1500 IU/ml hyaluronidase solution and two were immersed in saline as control. After 24 hours, there was a persistence of hyaluronic acid within the optic nerves.

CONCLUSIONS

There is a lack of evidence for penetration of optic nerve sheath by hyaluronidase. This raises question about the effectiveness of retrobulbar injection of hyaluronidase in reversing filler-related blindness. Further studies are needed before this can be adopted as the treatment of choice.

CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.