RESUMEN
OBJECTIVES: Ocular complications after spine surgery are incompletely understood and are not as rare as implied by recent publications. In 13 out of 15 published case reports, ocular complications are attributed mainly to compression. But in 66 cases reported in 4 series in the literature, compression seems to play a role in less than 10 cases. However, 3 out of the 4 series lack sufficient detail to support this mechanism clearly. Our objectives were to identify the mechanisms and specific risk factors associated with this devastating complication, to help in prevention. METHODS: A 2-page survey was sent to all French orthopedic centers specializing in spine surgery (28 centers) requesting information regarding any patients who had experienced visual deficits after spine surgery. Respondents were asked to identify presence of commonly cited preoperative risk factors, including ophthalmologic diagnosis and local signs (eyelid or conjunctival edema, periorbital numbness, or paresthesia) and intraoperative risks, such as positioning of the head, to clarify the possible mechanisms. Seventeen patients were thus included. RESULTS: Two main mechanisms were identified. First, ocular compression (9 cases) characterized by a unilateral definitive blindness with local signs due to a central retinal artery occlusion. Second, internal carotid thromboembolism (4 cases) associated with head rotation toward the ipsilateral side, causing an ischemic optic neuropathy with a unilateral partial and potentially regressive visual loss. CONCLUSIONS: The authors propose 2 preventive measures: modification of horseshoe-shaped headrest and precautions with lateral rotation of the head in patients with carotid atheroma.