Amaurosis after spine surgery: survey of the literature and discussion of one case

Abstract

Postoperative vision loss (POVL) associated with spine surgery is a well known, albeit very rare complication. POVL incidence after spinal surgery ranges from 0.028 to 0.2%; however, due to the increase in number and duration of annual complex spinal operations, the incidence may increase. Origin and pathogenesis of POVL remain frequently unknown. A 73-year-old patient presented with lumbar disc herniation with associated neurological deficits after conservative pre-treatment at a peripheral hospital. Known comorbidities included arterial hypertension, moderate arterial sclerosis, diabetes mellitus type 2, mildly elevated blood lipids and treated prostate gland cancer. During lumbar spine surgery in modified prone position the patient presented with an acute episode of severe hypotension, which required treatment with catecholamines and Trendelenburg positioning. Three hours postoperatively, a visual loss in the right eye occurred, resulting in a complete amaurosis. Antihypertensive medication, arteriosclerosis and intraoperative hypotension are possible causes for the POVL. Intraoperative administration of catecholamines and Trendelenburg positioning for treatment of systemic hypotension might further compromise ocular perfusion. In patients with comorbidities compromising arterial blood pressure, blood circulation and microcirculation, POVL must be considered as a severe postoperative complication. It is recommended to inform patients about such complications and obtain preoperative informed consent regarding POVL. Any recent modification of antihypertensive medication must be reported and analysed for potential intraoperative hemodynamic consequences, prior to spine surgery in prone position.

The Prone Position During Surgery and its Complications: A Systematic Review and Evidence-Based Guidelines

“…7,14,16,35À37,46,47 The reverse Trendelenburg position at 108 has been suggested to ameliorate raised intraocular pressure in prone position. 13,14,31,36,40,43,48 However, in surgeries involving the head or neck, this reverse Trendelenburg position should not be overdone, as this will increase the risk of venous air embolism. 49 If the Trendelenburg position is required during surgery, minimize time with the head below heart level.…”

“…35 Direct pressure on the orbits should be avoided and use of headrests that ensure pressure is off the orbits and ears is advised. 7,31,38,48 Asok et al recommends the Mayfield head clamp to prevent external pressure on the orbit. 50 Roth et al suggests using a square foam headrest and avoiding using a horseshoe head rest during cervical spine surgery, as frequent movement of the head increases risk of position change and increased orbital pressure.…”

“…13 Maintaining tight control of hemostasis, monitoring blood pressure by arterial line or central venous pressure line, and timely correction of anemia and hypotension is paramount. 16,31,35,36,48 Lower transfusion threshold and maintaining hematocrit above 30% in high risk patients is recommended.…”

“…31 Colloids along with crystalloids should be used for fluid management as this may theoretically reduce edema as high volumes of crystalloids are avoided. 16,37,48 Changes in perfusion-related medications prior to surgery should be avoided and preoperatively withholding medications that may reduce blood pressure or increase blood coagulability should be taken into consideration. 48 Ophthalmologic evaluation pre-operatively should be considered if the patient has personal or family history of acute angle-closure glaucoma.…”

“…16,37,48 Changes in perfusion-related medications prior to surgery should be avoided and preoperatively withholding medications that may reduce blood pressure or increase blood coagulability should be taken into consideration. 48 Ophthalmologic evaluation pre-operatively should be considered if the patient has personal or family history of acute angle-closure glaucoma. 39 Staging prone surgeries if duration is likely to be prolonged.…”