Hyaluronidase is a POM or Prescription Only Medicine in the UK. Its off label use in oculoplastic surgery is to “melt” hyaluronic acid gel (HA) used as filler in the face and around the eyes. As such it is “off license” . See the MHRA website which explains the use of the medical terms “licensed” and “off license”.
It explains that:
“A licensed medicine: has been assessed for efficacy, safety, and quality; has been manufactured to appropriate quality standards; and when placed on the market is accompanied by appropriate product information and labelling.”
The MHRA website goes on to say:
“However, there are clinical situations when the use of unlicensed medicines or use of medicines outside the terms of the licence (ie, ‘off-label’) may be judged by the prescriber to be in the best interest of the patient on the basis of available evidence.”
What can be done if the patient is very unhappy with the results of their hyaluronic acid gel filler? Fillers such as Restylane and Restylane Perlane, Juvederm etc. are very popular but sometimes there is an overfill….. The whole issue of why there is an overfill is not the subject of this article, but what is important here is how the physician can help the patient reverse the filler which otherwise could remain in their tissue for between six months and two years, depending on which type of hyaluronic acid gel filler has been used.
Oculoplastic and aesthetic surgeon, Jane Olver, of Clinica London says:
“I and many of my other oculoplastic colleagues receive many enquiries from patients who want to have their hyaluronic acid gel filler reversed – fortunately all of the Restylane and similar hyaluronic acid (HA) gel treatments are reversible with the injection of an enzyme called Hyaluronidase. This is an off licence use of this prescription only medicine (POM) and should only be used when the physician believes that it is in the best interest of the patient and that the available evidence supports this.
“One of the biggest problems I am seeing is from patients who are still having the old fashioned technique of a big lake of Restylane injected into the tear troughs and cheeks – it doesn’t look nice often producing a bluish/silvery tinge to the skin, lumpy areas and it can shift around.
“With the huge number of patients now having fillers, and until fillers administration is more regulated, it is not surprising that there are patient who are unhappy with their appearance after filler. It may simply not have lived up to their expectations, or it might have been injected in the wrong placeh using a poor technique. Possibly too much filler was used when a smaller quantity in conjunction with surgery might have produced a better result. I am a strong believer in doing less and producing a more subtle result in aesthetic and facial rehabilitation after disease”, said Jane Olver.
“Sometimes the patient has had just a little bit too much put into the cheeks creating an asymmetrical appearance. This is a difficult situation for practitioners because in nature all faces have a degree of asymmetry. There is an art to using hyaluronic acid gels such as Restylane in a face that is asymmetrical – there is a fine line to making it symmetrical. It is a highly skilled art form and even in the best hands things can work out unexpectedly.”
The length of time for the effects of the hyaluronic acid gel product to last in the face depends on the ‘heaviness’ of the HA gel, the quantity that has been used, as well as the position of the treatment.
Before any injection of hyaluronidase is made, the patient must be advised of the potential risks of hyaluronidase, consent must be obtained and advice given on what they should do if they are having a reaction to the injection. Complications of soft tissue injection of Hyaluronidase include pain on injection, redness, bruising, swelling and allergic reaction.
Hyaluronidase comes in 1 ml vials and is mixed with sterile saline for injeciton. It is used in tiny quantities dependent on how much HA gel needs to be melted away. Before reversal treatment, the powder is mixed with a saline solution so that it doesn’t hurt.
The injection must be given in sterile conditions with the skin cleaned beforehand and the surgeon wearing sterile gloves. A minute amount of Hyaluronidase is injected through the skin (trans-cutaneously) into the overfilled tear trough or cheek site. The enzyme Hyaluronidase quickly breaks down the extracelular hyaluronic acid gel, thus causing the gel to “disappear”.
Jane Olver injects where she can palpate or see the excess Restylane is such distressed patients. It will work within minutes and the next morning the patient can expect the tissue to feel and look a little bit deflated where it before had the filler.
Research suggests that the enzyme hyaluronidase has no effect on the patient’s own hyaluronic acid.
However, “reducing dermal fillers is not a licensed indication for Wockhardt UK Limited’s Hyaluronidase 1500 I.U. Powder for Solution for Injection / Infusion. There is no safety or efficacy data to support the use of the aforementioned product in reducing dermal fillers.” according to the Drug Safety and Information Department of the supplier Wockhardt UK Limited, personal communication.
“There is also no direct scientific equation indicating the exact quantity of Hyaluronidase to use – it is a matter of judgement and experience. Most often patients expect to have more filler afterwards– injected with the correct quantities and technique. Very occasionally a patient might be thrilled to see the return of her eye bags – but that is rather rare!” , says Jane Olver
Risks with Hyaluronidase appear to be few, however a very small number of people may be allergic to the enzyme. “I make sure that all my patients are covered with a prescription of Piriton and a small dose of steroid (Prednisolone) in case of allergy”, said Jane.
Hyaluronidase is not a new product having been known to the ophthalmic world for more than 30 years. It was extensively used in cataract surgery in the 1980’s when intracapsular cataract extraction was practiced.
The use of Hyaluronidase by a physician is off license and it must only be with the patients full informed consent and where the physician believes that it will help that patient and be in their best interest to have this treatment, as there are no proven studies that show its efficacy or safety to dissolve hyaluronic acid gels. Hence it is ermed an “off license” medicine.