Excessive molding of the filling can also compress the filling into a foramen, leading to compression of a nerve that causes paresthesia. There are seven danger zones for facial nerves that should be avoided when injecting fillers into the face. Park SW, Woos SJ, Park KH, Huth JW, Jung C, Kwon OK (201) Iatrogenic retinal artery occlusion caused by injections of cosmetic facial fillers. In different non-surgical facial procedures, fillers are used to inject into the skin layers of the dermis and middle dermis.
The key to injecting fillers is to inject the right filler at the right level to the right patient and also at the right time. Loh KT, Chua JJ, Lee HM, Lim JT, Chuah G, Yim B, Puah BK (201) Prevention and treatment of vision loss related to facial filler injections.