Does hyaluronidase injected in periocular area change skin ultrastructure?: Standardized in vitro analysis.

[BACKGROUND] Treatment with hyaluronic acid (HA) fillers as a strategy for rejuvenation has experienced a significant growth in recent years, accompanied by a parallel increase in its complications, the treatment of which, such as hyaluronidase, we must be aware of.

[PATIENTS/METHODS] 14 patients (28 eyes) had indication for upper blepharoplasty surgery in the Hospital Universitario y Politécnico La Fe. After surgery, periocular skin of one eye of each patient was infiltrated with 300 U of hyaluronidase (14 cases) while the skin of the fellow eye was preserved untreated (14 controls). All samples were studied by the Pathology department, and finally, 6 variables (skin structure alteration, degeneration of elastic fibers, deposits, collagen fibers destructuring, inflammation, and other findings) were analyzed.

[RESULTS] No differences in skin structure, elastic fibers, and collagen dermal fibers were found between hyaluronidase-treated skin and controls. A significant association between ex vivo application of hyaluronidase in periocular skin and the presence of amorphous extracellular deposits within the dermis was found.

[CONCLUSIONS] Hyaluronidase applied ex vivo to periocular skin led to presence of deposits within the extracellular matrix compared to control eyelid skin but elastin and collagen dermis structure remained unaltered.