Ischemic optic neuropathy after lumbar spine surgery
D. M. Katz, J. D. Trobe, W. T. Cornblath and L. B. Kline
Department of Ophthalmology (W. K. Kellogg Eye Center, University of Michigan Medical Center, Ann Arbor.
OBJECTIVE: Study of clinical features of ischemic optic neuropathy (ION)
developing as a complication of multilevel lumbar spine surgery. DESIGN:
Review of all cases of ION that developed within 2 weeks of spine surgery
at two academic institutions from 1990 to 1992, and a review of adequately
reported cases of ION after other non-ophthalmic procedures. RESULTS: Four
new cases are reported in patients who ranged in age from 41 to 65 years.
All four had undergone uneventful but prolonged (8 to 9 hours) spine
surgery, during which blood pressure was deliberately maintained between 85
and 100 mm Hg systolic and 45 to 65 mm Hg diastolic to reduce bleeding.
Hemoglobin values fell 30 to 78 g/L during surgery. Arteriosclerotic risk
factors, including systemic hypertension, diabetes, coronary artery
disease, and smoking, were present in three cases. There was no evidence of
orbital soft-tissue injury, retinal artery occlusion, or other neurologic
deficits. The combination of hypotension and anemia has been noted in most
of the 30 previously well-documented cases of ION after other
non-ophthalmic procedures. CONCLUSIONS: Multilevel lumbar laminectomy
should be added to the list of procedures that may produce ION as an
isolated complication. Deliberate hypotension maintained for long operative
periods in patients with arteriosclerotic risk factors may be the cause.
