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[1] [2] This reduced axonal transport can then cause swelling or bulging on the surface layer of the retina, increasing the potential for nerve fiber damage. [2] The presence of cotton wool spots may resolve independently over time, typically in 4–12 weeks, or may depend on the underlying disease causing the condition.
Advanced retinopathy lesions, such as microaneurysms, blot hemorrhages and/or flame hemorrhages, ischemic changes (e.g. "cotton wool spots"), hard exudates and in severe cases swelling of the optic disc (optic disc edema), a ring of exudates around the retina called a "macular star" and visual acuity loss, typically due to macular involvement.
Similar to hypertensive retinopathy, evidence of nerve fiber infarcts due to ischemia (cotton-wool spots) can be seen on physical exam. Symptoms may include headache, nausea, or vomiting. Chest pain may occur due to increased workload on the heart resulting in inadequate delivery of oxygen to meet the heart muscle's metabolic needs.
Byssinosis [n 1] is an occupational lung disease caused by inhalation of cotton or jute dust in inadequately ventilated working environments and can develop over time with repeated exposure. [ 2 ] [ 3 ] Byssinosis commonly occurs in textile workers who are employed in yarn and fabric manufacture industries.
Ischemia is a vascular disease involving an interruption in the arterial blood supply to a tissue, organ, or extremity that, if untreated, can lead to tissue death. It can be caused by embolism, thrombosis of an atherosclerotic artery, or trauma. Venous problems like venous outflow obstruction and low-flow states can cause acute arterial ischemia.
However, there is little direct evidence for involvement of axonal transport in the latter diseases, and other mechanisms (such as direct synaptotoxicity) may be more relevant. Arrest of axoplasmic flow at the edge of ischemic areas in vascular retinopathies leads to swelling of nerve fibres, which give rise to soft exudates or cotton-wool patches.
Infarction occurs as a result of prolonged ischemia, which is the insufficient supply of oxygen and nutrition to an area of tissue due to a disruption in blood supply.The blood vessel supplying the affected area of tissue may be blocked due to an obstruction in the vessel (e.g., an arterial embolus, thrombus, or atherosclerotic plaque), compressed by something outside of the vessel causing it ...
Fundus examination revealed choroidal folds inferior to the optic disc and a single cotton-wool spot in the inferior arcade of the right eye (white arrow). The second case of visual changes during long-duration spaceflight on board the ISS was reported approximately 3 months after launch when the astronaut noticed that he could now only see ...