Hyaluronidase in Ophthalmology

ABSTRACT Purpose The application of hyaluronidase in ophthalmology dates back 60 years, when it was first included in retrobulbar blocks. Now it is used routinely in retrobulbar, peribulbar, and sub-Tenon’s blocks. Until recently, the only sources of hyaluronidase were animal derived, either pharmaceutically manufactured or compounded. Animal-derived products have been associated with low purity, variable potency, and uncertain safety. Given these concerns, use of recombinant human hyaluronidase merits consideration to help improve the safety and quality of local anesthetic blocks. In order for practitioners to make informed therapeutic decisions regarding the use of hyaluronidase in ophthalmology, the safety and efficacy of available products must first be evaluated. Design We analyzed multiple clinical samples from national and regional compounding pharmacies for purity and potency, and compared them to recombinant human hyaluronidase. In addition, a literature search, including the Food and Drug Administration Adverse Event Reporting System (FDA AERS) database, was performed to further evaluate adverse event and safety data. Results The laboratory analyses demonstrated that animal-derived hyaluronidase, specifically compounded products, has variable purity and potency, whereas recombinant human hyaluronidase possesses high purity and consistency. The literature supported routine inclusion of hyaluronidase in anesthetic blocks to help reduce the potential for complications. Although compounded animal-derived preparations have been used extensively, their varying levels of impurities and their potential for allergic reactions may create unnecessary risk. Hyaluronidase in Ophthalmology