Cotton wool spots
[5] Cotton wool spots are a retinal condition that when present, frequently act as a significant indicator, or sign, of a variety of underlying disease states.
[9] Referred to as a form of retinal myopathies, cotton wools spots are commonly found to be a secondary manifestation to diseases like diabetes, hypertension, and AIDS.
[2] One study observed the presence of cotton wool spots in people with acute leukemia, referring to the increase in white blood cells as a probable cause.
[15] Cotton wool spots have different clinical characteristics when present as a result of HIV rather than in systemic diseases, like diabetes or hypertension, due to the viral complexes that cause structural changes to the retinal microvasculature.
[3] Cotton wool spots are also associated with giant cell arteritis (GCA), a type of inflammation of the lining of the arteries, as this may reduce blood flow to the eyes.
[5] A study conducted at Wills Eye Hospital in Pennsylvania found that a potential side effect of medications like macitentan, an endothelin receptor antagonist that is used to treat pulmonary arterial hypertension, can be bilateral cotton wool spots.
[16] As such, if a person develops cotton wool spots after starting an endothelin receptor antagonist, medication side effect should be considered as a plausible cause.
In a study of four subjects, two male and two female, with chronic migraines and no other present risk factors for cotton wool spots, such as normal hemoglobin A1C and blood glucose (indicating no diabetic risk), no indicators of being immunocompromised, and having blood pressures under 140/90 mm Hg (no chronic hypertension), presented with cotton wool spots in one of their eyes.
Since no other risk factors were present and the common factor between the four subjects was chronic migraines, the study postulates that vasospastic syndromes common in those with chronic migraines may lead to ischemia in the eyes leading to the formation of cotton wool spots, as cotton wool spots can also act as an indicator of general vasospastic activity.
[1] The emergence of advanced technological tools like SD-OCT are providing new insight of neurosensory retinal health in vivo, especially in cases such as analysis of the retina post-resolution of cotton wool spots.
[1] However, funduscopic exams that find patchy opaque areas on the retina may misdiagnose the condition as cotton wool spots instead of transient branch retinal artery occlusion (BRAO) which also does not effect vision and self-resolves.
Once these areas of opacity resolve and the retina evaluation returns to normal, a fluorescent angiography is performed to determine lasting damage to the obstructed retinal capillaries.
