Current intraoperative devices to reduce visual loss after spine surgery

Postoperative visual loss (POVL) after spine surgery performed with the patient prone is a rare but devastating postoperative complication. The incidence and the mechanisms of visual loss after surgery are difficult to determine. The 4 recognized causes of POVL are ischemic optic neuropathy (approximately 89%), central retinal artery occlusion (approximately 11%), cortical infarction, and external ocular injury. There are very limited guidelines or protocols on the perioperative practice for prone-position surgeries. However, new devices have been designed to prevent mechanical ocular compression during prone-position spine surgeries. The authors used PubMed to perform a literature search for devices used in prone-position spine surgeries. A total of 7 devices was found; the authors explored these devices' features, advantages, and disadvantages. The cause of POVL seems to be a multifactorial problem with unclear pathophysiological mechanisms. Therefore, ocular compression is a critical factor, and eliminating any obvious compression to the eye with these devices could possibly prevent this devastating perioperative complication. (http://thejns.org/doi/abs/10.3171/2009.8.FOCUS09151)