Vision loss associated with orbital surgery - a major review. 
Purpose: Vision loss after orbital surgery is one of the most dreaded complications faced by the orbitofacial surgeon.  This literature review was conducted in an attempt to determine the risk factors for severe vision loss and discuss the applied anatomy related to various types of orbital surgery - orbital tumor excisions, orbital decompression, and post-traumatic orbital reconstruction.  Methods: A literature search was conducted via PubMed and Google Scholar.  All cases of vision loss following orbital tumor biopsy or excision, orbital decompression, and orbital trauma reconstruction were reviewed.  Results: The incidence of postoperative blindness appears to be more after orbital tumor excisions (4.7%), compared to post-traumatic orbital reconstruction (2.08%) and orbital decompressions for thyroid orbitopathy (0.15%).  The causes of vision loss include ischemic optic neuropathy, traumatic optic neuropathy, retinal and ophthalmic artery occlusions, and orbital compartment syndrome.  Conclusion: Apart from careful patient selection, proper counseling about the risk of postoperative blindness is of utmost importance.  Detailed preoperative treatment planning, meticulous atraumatic intraoperative dissection under direct visualization, with attention to the danger zones and vital structures, close intraoperative and postoperative monitoring, and urgent management of potentially reversible compressive causes of vision loss can improve outcomes.