Which of the following conditions does not contribute to the development of cotton wool spots?

Cotton wool spots are soft exudates that occur in the retina and are commonly associated with various systemic conditions. They arise due to localized ischemia, which results from the accumulation of axoplasmic material in ganglion cell layers of the retina. Among the conditions listed, hypertension, diabetes mellitus, and chronic kidney disease are all closely associated with the development of cotton wool spots due to the vascular changes and damage they cause to the retinal blood vessels.

Hypertension can lead to damage and occlusion of small retinal vessels, while diabetes mellitus is known for its complications, including diabetic retinopathy, which can also result in cotton wool spots. Chronic kidney disease is linked to a range of systemic vascular changes that can impact retinal health. In contrast, hyperthyroidism does not have the same direct connection to ischemic changes leading to cotton wool spots. While it can have various effects on ocular health, such as in Graves’ disease leading to thyroid eye disease, it is not typically associated with the ischemic processes that result in the development of cotton wool spots.

Thus, the correct answer to the question is hyperthyroidism, as it is the condition that does not contribute to the formation of cotton wool spots in the retina.