Cotton wool spots are commonly seen in –a) AIDSb) DMc) Hypertensiond) CMV
Causes of soft exudates (cotton wool spots)

All types of severe hypertension (hypertensive retinopathy) including renal disease, Toxemia of pregnancy.
Diabetic retinopathy
Collagen vascular disorders :- SLE, PAN, systemic sclerosis, scleroderma, wegener granulomatosis.
Infections :- AIDS, septic retinitis (including SABE), rarely CMV retinitis in AIDS.
Microembolization :- IV drug abuse, Post cardiac surgery, Fat embolism or Purtscher retinopathy.
Other Eale's disease, Adults anemia (Hb < 6.6-8.0 g/d1), Pseudoxanthoma elasticum, Neoplasia (Leukemia, Hodgkin's disease), Sickle cell retinopathy, radiation retinopathy
Now you must be thinking, why have I not included CMV in the answer? Read question carefully, examiner is asking about common causes. In CMV retinitis, cotton wool spots occur rarely.
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