Anemia/Thrombocytopenia: Retinal Hemorrhages, Roth Spots
All three types of retinal hemorrhages (dot-blot, flame, boat-shaped) can occur when the hemoglobin falls below 8 gm/100 ml or if the platelet count falls below 50,000/mm3. The combination of severe anemia and thrombocytopenia is likely to produce retinal hemorrhages in a majority of patients.
To learn more about retinal hemorrhages and their causes, see Retinal Hemorrhages.
probably reflect microinfarcts, just like cotton wool spots. The white center consists of arrested axoplasm.
They are especially common in severe anemia, for uncertain reasons. Perhaps the low oxygen-carrying capacity renders the vessel wall hypoxic and triggers small occlusions.
What to do?
Retinal hemorrhages and cotton wool spots may be the first clue to a blood dyscrasia. As they often do not interfere with vision, they should be sought in a thorough evaluation of a patient with manifestations suggesting anemia or thrombocytopenia.