Ischemic optic neuropathy: are we any further?

Area of Science:

• Ophthalmology
• Neurosurgery
• Anesthesiology

Background:

• Postoperative vision loss (POVL) following spinal surgery, particularly in the prone position, has increased over the last 15 years.
• This rise is potentially linked to advancements in complex spinal instrumentation techniques.
• The American Society of Anesthesiologists established a Postoperative Visual Loss Registry to study this complication.

Purpose of the Study:

• To review and understand the causes and risk factors of postoperative vision loss (POVL) in spinal surgery.
• To evaluate the current understanding of ischemic optic neuropathy (ION) as a complication of spinal surgery.
• To identify potential preventative measures for ION.

Main Methods:

• Review of retrospective studies on POVL and ION.
• Analysis of risk factors identified in existing literature.
• Incorporation of anatomical knowledge and findings from animal studies.

Main Results:

• The exact cause of ischemic optic neuropathy (ION), a complex form of POVL, remains undetermined.
• ION affects patients of all ages but shows increased incidence in those under 18 and over 65.
• Identified risk factors include male sex, anemia, prolonged surgery (>6 hours), and intraoperative hypotension.

Conclusions:

• Ischemic optic neuropathy (ION) is not well understood, and its risk factors are speculative.
• Currently, no effective treatment exists for ION.
• Further research into the mechanisms of ION is crucial for developing preventative strategies.