A 30 year old patient with history of recurrent headache was sent for fundus evaluation. He was found to be having generalized arterial attenuation with multiple cotton wool spots and flame shaped haemorrhages in both eyes. The most likely cause is –
Recurrent headache with fundoscopic finding of generalized arterial attenuation, multiple cotton wool spots and flame shaped hemorrhage suggest the diagnosis of hypertensive retinopathy.
Cotton wool spots and flame shaped hemorrhage can also occur in diabetic retinopathy. But following features are not in favour of diabitic retinopathy :-


Symptoms of diabetes (polyuria, polyphagia, polydipsia) have not been mentioned
Recurrent headache is more often a symptom of hypertension
Most importantly, "Arterioler attenuation is not common in diabetic retinopathy". — Basic of ophthalmology
Diabetic retinopathy
Hypertensive retinopathy
Central retinal artery occlusion
Temporal arteritis