Cotton wool spots are common retinal findings during an eye exam. These spots appear as fluffy white or grayish areas on the retina and are caused by ischemia to the nerve fiber layer. There are several possible causes of cotton wool spots.
The most common cause of cotton wool spots is hypertension or high blood pressure. High blood pressure can damage the small blood vessels in the retina, causing them to leak and leading to the formation of cotton wool spots. Other causes of cotton wool spots include diabetes, HIV infection, and autoimmune diseases.
In addition, cotton wool spots can also be caused by blockages in the retinal blood vessels, which can occur as a result of blood clots or other types of vascular disease. Rarely, cotton wool spots may be a sign of more serious conditions, such as a brain tumor or leukemia.