Abstract
Introduction: Hyaluronidases are a group of enzymes that depolymerize hyaluronic acid (HA). Hyaluronidases decreases the high viscosity of HA and increases the permeability of blood vessels and connective tissue.
Hyaluronidases is used in aestheticmedicine and cosmetic surgery, dermatology, in local and locoregional retrobulbar peribulbar block and by ophthalmologists for sub-tenonanaesthesia.
Discussion: Hyaluronic acid is the most used product in aesthetic medicine, especially for the facial region.It is a major ingredient in many medical and anti-aging treatments with its main quality it being a substance that is naturally present in the human body (joints and subcutaneous tissues.) Its post treatment tolerance is excellent with few side effects and rare post-operative complications.
Used to correct excess hyaluronic acid, hyaluronidase can be extracted from several sources e.g. snake or bee venom, testes of mammals (cattle), certain types of group A, B or C streptococci.
There are currently several specialties including a human recombinant. (synthetic product)
-Hydrase * and Amphadase * of bovine origins
-Vitrase * and hyalase * of sheep origins
-Hylenex * of recombinant origin offering fewer side effects.
-Aestheticderma desinfiltral

The mechanism of action of hyluronidase is based on hydrolysis by breaking the glucosaminidic links between Chain 1 of glucosamine and Chain 4 of gluconic acid.It also breaks other acid mucopolysaccharides in the connective tissue.
The injection technique is simple.However, some side effects and complications can be observed:nodules, granulomatous reactions or simple over-corrections that improve within an hour after the injection to disappear completely after 12 hours or else the tyndall effect (inflammation in the aqueous humor),cutaneous necrosis of arterial origin.hence the interest of a recombinant human hyaluronidase with risks of almost zero side effects.

CONCLUSION
Hyaluronidase is used in many fields: in ophthalmology, locoregional anaesthesia, cosmetic surgery and dermatology. It is very effective and relatively simple to handle, but not completely harmless: allergy and infectious transmission may occur.
The marketing of a recombinant human hyaluronidase with a marketing authorization which is already present in other European countries and in the United States, seems more than ever desirable today.

Key words: Hyaluronidase, aesthetic medecine, indications