Eventi avversi oculari in chirurgia generale e specialistica: epidemiologia, diagnosi, prevenzione e aspetti gestionali

Post-Operative Visual Loss (POVL) is a rare, but devastating, complication that can be seen following non-ocular surgeries. The specific pathogenesis remains elusive in most cases, with much controversy surrounding patients and surgical risk factors. A great number of publications have speculated on causation but unfortunately, given the rarity of POVL, they are based solely on retrospective data. Although these reports have suggested possible causes, including patient positioning, blood loss and intra-operative hypotension, direct causal relationships have rarely been demonstrated and the cause of this unusual but devastating complication remains unclear. The most important causes of POVL are Ischemic Optic Neuropathy (ION), Central Retinal Artery Occlusion (CRAO), Cortical Blindness (CB) and external ocular injury. The two different forms of ION, anterior and posterior, are the most common (approximately 89%), while the second most frequent cause of POVL identified in the literature (approximately 11%) is CRAO. This project reports some of the latest publications about POVL, most of them focusing on the peri-operative changes of Intra-Ocular Pressure (IOP). The elevation of IOP can lower the ocular perfusion pressure despite the maintenance of the normal Mean Arterial Pressure (MAP). Decreased perfusion of the retinal and optic nerve may result in postoperative visual disturbance. The factors that may influence the increase of IOP are the prone surgical position, the Trendelenburg Positioning (TP), the intra-operative fluid balance, the anesthetic drugs and the type of supra-glottic airway management device.