Macular cotton wool spot

What it means

Fluffy white patch in the macula, representing localized areas of dense white swelling of the retinal nerve fiber layer.

Cotton-wool spots (CWSs) are common retinal manifestations of ischemia in the inner retina, due to many diseases including diabetes mellitus, systemic hypertension, and acquired immunodeficiency syndrome.

Rare diseases that can present with this1

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category