Cotton-wool spots are tiny white areas in
the retina, the layer of light-sensing cells
lining the back of the eye. Caused by small
vessel occlusions. They appear as puffy
white patches on the retina. They are caused
by damage to nerve fibers. The nerve fibers
are damaged by swelling in the surface layer
of the retina. The cause of this swelling is
due to the reduced axonal transport (and
hence backlog of intracellular products)
within the nerves because of the ischemia.
SIGNS & SYMPTOMS
Various degree of blurry vision Localized, white-yellowish, fluffy areas
of nerve fiber layer edema
DETECTION AND DIAGNOSIS
They are an abnormal finding on
funduscopic exam of the retina of the eye.
Diabetes and hypertension (high blood
pressure) is the most common cause of
cotton-wool spots. The presence of more than
eight cotton-wool spots has been associated
with a higher risk of the more severe form
of diabetic retinopathy known as
proliferative diabetic retinopathy.
Cotton-wool spots are also a common sign of
infection with the Human Immunodeficiency
Virus (HIV). Their presence can be an
important sign of the severity of
They usually disappear without treatment and
do not threaten vision. They are, however,
and indicator of a possible medical
condition, which may need treatment, and
therefore a work-up is indicated.