Endoscopic diagnostic and surgical orbital approach in canines.

The aim of this study is to describe new diagnostic and surgical orbital approaches using video endoscopy in canines. Four different endoscopic approaches were investigated in this study of video endoscopy in cadavers: dorsal transorbital ligament approach via incision of the orbital ligament (DTOLA), dorsal subpalpebral transconjunctival approach (DSTA), ventral subpalpebral transconjunctival approach (VSTA), and transoral orbital approach (TOA). Two additional approaches, the ventral transpalpebral approach (VTA) and dorsal caudal transmuscular approach (DCTA) along with the DTOLA and DSTA were used in clinical patients. The most technically demanding approach was DTOLA; however, it provided the best visualisation of different anterior and posterior orbital structures. Visualisation of primarily the dorsal orbital wall, dorsal portion of the eye globe, and dorsal extraconal space also was achieved by DSTA. The VSTA enabled good visualisation of the ventral orbital floor and the ventral extraconal and intraconal space. In contrast, the TOA provided relatively poor visualisation of orbital structures, limited to the ventral orbital quadrant. Meanwhile, the VTA provided visualisation similar to the VSTA, while DCTA visualisation was limited to the dorsal and caudal orbital space. Orbital endoscopy is an effective and minimally invasive procedure that can be used for diagnostic and surgical orbital procedures.