Central retinal artery occlusion - rethinking retinal survival time

Area of Science:

• Ophthalmology
• Neurology
• Vascular Medicine

Background:

• The time from central retinal artery (CRA) occlusion to retinal infarction is critical for treatment and has medical-legal implications.
• Central retinal artery occlusion (CRAO) can complicate therapeutic interventions, necessitating a clear understanding of infarction timelines.

Purpose of the Study:

• To review the evidence for the time to infarction following complete CRAO.
• To discuss the implications of the actual time to retinal infarction for treatment strategies and patient outcomes.

Main Methods:

• A comprehensive literature search of Medline and the internet was conducted.
• Keywords included "central retinal artery occlusion", "retinal infarction", "retinal ischemia", and "cherry red spot" from 1970 to the present.
• Retrieved references and their bibliographies were screened for relevance.

Main Results:

• Existing evidence suggests inner retinal infarction occurs within 90-240 minutes of CRAO, but this is flawed.
• Retinal ganglion cells, part of the central nervous system, infarct after 12-15 minutes or less of non-perfusion.
• Inner retinal infarction is likely to occur after only 12-15 minutes of complete CRAO.

Conclusions:

• Rapid infarction (12-15 minutes) explains the frequent ineffectiveness of therapeutic maneuvers for CRAO.
• Incomplete CRAOs may still benefit from therapy after longer intervals.
• To prevent infarction from inadvertent ocular compression during prone anesthesia, eyes require checks every <15 minutes.