A new way to use hyaluronidase for vision loss after hyaluronic acid injections

Новый способ применения гиалуронидазы при потере зрения после инъекций гиалуроновой кислоты

Every year, the number of cases of vision loss after filler injections is increasing worldwide. It is almost always impossible to reverse the occlusion of the central retinal artery. However, the literature describes a case of restoration of vision by retrobulbar administration of hyaluronidase. In this article, estet-portal.com, Dr. Melissa Mccann offers a relatively safe and previously unconsidered treatment for blindness after HA injections – intravenous administration of hyaluronidase. In the author's opinion, this approach may be effective if it is not possible to perform a retrobulbar injection within 60-90 minutes after the onset of a complication.

Pathophysiological and anatomical mechanism of vision loss after filler injections
Current Recommendations: Hyaluronidase Injections for CAS Occlusion
Intravenous hyaluronidase as an alternative approach to vision restoration after fillers

Anatomical and pathophysiological mechanism of vision loss after filler injections

The pathophysiological and anatomical mechanism of vision loss after filler injections is well documented in the literature. After the introduction into the artery of the face – branch of the facial and external carotid artery – the filler clot migrates retrograde and then anterograde to ophthalmic or central retinal artery (CAS). The occlusion that results from intravascular injection of a filler may be local or diffuse.

In the context of vision loss, the areas of greatest risk are the areas between the eyebrows and the nose. However, variability in facial vascular anatomy and other factors contribute to the likelihood of blindness following filler injections in virtually any area of the face. Current Recommendations: Hyaluronidase Injections for CAS Occlusion

According to current recommendations,

Instillation of timolol into the affected eye;

Hyaluronidase

. If vision is not restored, the ophthalmologist injects the enzyme retrobulbar, as well as in the supraorbital and supratrochlear foramen.

The effect of HA degradation under the action of the hyaluronidase enzyme is almost instantaneous.

The use of these techniques is due to the fact that hyaluronidase easily diffuses into the cavity of the vessels.Despite existing prevention methods and recommendations for safe contouring, blindness following filler injections remains a medical emergency for which there is no

proven treatment.

Intravenous administration of hyaluronidase as an alternative approach to the restoration of vision after fillers

In the course of studies on the treatment of myocardial infarction, the authors resorted to intravenous bolus administration of hyaluronidase at a dose of 500 IU/kg. In some cases, the enzyme was administered again after 6 hours. The half-life of the drug is about 2-5 minutes. Hyaluronidase injections are associated with the risk of moderate adverse events, and no cases of anaphylaxis were reported in this study.

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The author suggests that

hyaluronidase at a dose of 200 & ndash;250 IU/kg can be administered intravenously

if other therapeutic measures have not led to the restoration of vision after injections of HA fillers.

Instagram! Thus, for an adult weighing 70 kg, approximately 10 ampoules of Hyalase will be needed, the total dose is 15,000 IU.

1 ml of saline is injected into each ampoule of the drug, the resulting solution is drawn into a syringe. In this way, 15 000 IU of hyaluronidase is obtained in 10 ml of saline.

After the IV cannula is in place, the patient is given a bolus of the resulting solution, followed by another 10 ml of saline to flush. The patient remains in the supine position.

In case of anaphylaxis, epinephrine and oxygen must be prepared.

Over the next 5–10 minutes

, the hyaluronidase concentration is expected to be

IU/ml circulating blood volume (based on , which in the average volume of the patient's blood is 5 l). It is assumed that with the first or second systolic blood volume, hyaluronidase will enter the internal and external carotid arteries, and after that – into the facial artery and its anastomoses with the central retinal artery, where it will start the process of degradation of hyaluronic acid. It is likely that as early as 2–3 minutes constant flow of enzyme, in combination with repeated breathing and orbital massage,

restore the patency of the retinal artery or ciliary arteries

. You may also be interested in:

Hyaluronidase enzyme in cosmetology: elimination of side effects of fillers Most likely, a sufficient concentration of hyaluronidase in the cavity of the surrounding and anastomosing vessels will persist for more than a few minutes and vision will be restored. In addition, circulating hyaluronidase can dissolve other arterial emboli that complicate about 24% of cases of vision loss after injections of hyaluronic acid fillers.

Intravenous bolus, as well as retrobulbar hyaluronidase injection, refers to cases of

off

label enzyme, and therefore this item should be included to informed consent for contouring. Read also: First aid for central retinal artery occlusion after filler injections

Despite the use of the correct injection technique, cannula work, aspiration test, knowledge of anatomy and depth of drug injection, loss of vision after filler injections remains a serious problem for aesthetic medicine doctors.

Intravenous administration of high doses of hyaluronidase eliminates the shortcomings of current management protocols for this complication:

Intravenous cannula insertion takes less time than retrobulbar injections of the drug;

the doctor will be able to quickly prepare a bolus that will provide the necessary concentration of hyaluronidase in the blood until the hyaluronic acid dissolves;