What is the most immediate threat to vision in an acute angle closure?

In the context of acute angle closure, the most immediate threat to vision is Central Retinal Artery Occlusion (CRAO). When an acute angle closure occurs, it typically leads to a rapid increase in intraocular pressure. This elevated pressure can compromise blood flow to the retina, particularly affecting the central retinal artery, which supplies blood to a significant portion of the retinal tissue.

If this artery becomes occluded, it results in a sudden loss of vision due to ischemia of the retina, which is acute and often irreversible if not addressed promptly. The symptoms associated with CRAO, such as sudden vision loss, can occur within minutes of the angle closure event, highlighting its immediacy as a vision-threatening condition.

While Central Retinal Vein Occlusion (CRVO), retinal detachment, and cataract formation can indeed affect vision, they do not occur as rapidly or acutely as CRAO in the setting of acute angle closure. CRVO tends to present symptoms more gradually, retinal detachment may lead to progressive vision loss, and cataracts develop over longer periods, making CRAO the most urgent concern in this scenario. Understanding the pathophysiology and the time sensitivity of these conditions is crucial for managing acute angle closure effectively.