During an episode of retinal artery occlusion, how long can the retina survive without blood supply?

The correct response indicates that the retinal tissue can survive without a blood supply for approximately 90-100 minutes during an episode of retinal artery occlusion. This timeframe is critical because the retina, specifically the inner layers, is quite sensitive to ischemia or lack of oxygen and nutrients supplied by blood.

When an artery supplying the retina is occluded, the cells begin to experience metabolic distress due to the deprivation of essential blood flow. Neurological tissues, including the retina, have limited reserves of metabolic substrates and lack the ability to recover from prolonged ischemia. After about 90-100 minutes, irreversible changes occur in the retinal cells as they undergo necrosis; this can lead to permanent vision loss.

In contrast, options that suggest survival times outside the range of 90-100 minutes would either overestimate or underestimate the critical time frame for retinal tissue. For instance, claiming that the retina can survive for more than 240 minutes disregards the biological limitations of retinal cells to endure ischemia. It's important for clinicians to recognize the urgency of addressing retinal artery occlusions within this timeframe to prevent irreversible damage and promote better outcomes for patients.