Perioperative visual loss

Most Common Causes of Perioperative Visual Loss

Corneal abrasion Retinal ischemia Ischemic optic neuropathy Symptoms Painful foreign body sensation, visual acuity may be intact Painless loss of vision Unilateral Periorbital edema Proptosis Chemosis Extraocular muscle injury Ecchymosis Painless loss of vision Bilateral Etiology Corneal epithelial defect in anterior segment Central retinal artery occlusion Branch retinal artery occlusion (retinal microemboli or vasospasm) Elevated intraocular pressure Unknown, perhaps related to optic nerve ischemia, vascular insufficiency, although often no other clinically significant end-organ damage Risk factors Unprotected, exposed eyes Intraoperative contact lens use Prone positioning Spine surgery Cardiac surgery, bypass External orbital pressure Prone positioning Spine surgery (PION) Cardiac surgery (AION) Prolonged surgery ?Deliberate hypotension ?Hypoxia ?Hemodilution ?Vasoconstrictors ?Anemia ?Elevated venous pressure (e.g., Trendelenburg) Diagnosis Slit lamp examination withfluorescein Afferent pupillary defect Pale swollen optic disc Cherry red retina Ground glass retina Afferent pupillary defect or nonreactive pupil (CNII) AION: optic disc edema PION: normal optic disc Abnormal visual-evoked potentials Treatment Antibiotic drops IV acetazolamide 5% CO2 + O2inhalation Ocular massage ?Ophthalmic artery fibrinolysis Attempt to optimize oxygenation and orbital perfusion pressure, although no definitive treatment Prognosis Good prognosis Expect recovery Poor prognosis Permanent visual loss Poor prognosis Permanent visual loss Prevention Tape eyes securely No benefit to lubricant Remove contact lenses Avoid external orbital pressure Frequently examine eyes during prone cases Stage long spine procedures Nadir hematocrit does not differ in patients with ION and those unaffected in noncardiac surgery Massive fluid replacement may be a risk factor for ION (no clear evidence)