Gunn1 used the term copper wire to describe retinal arteries with a lighter than usual over-all color and a sharp exceptionally bright central light streak. He noted such arteries in some patients with albuminuria and in others with hypertension, and he presumed that this ophthalmoscopic appearance was due to hyaline degeneration of the arterial wall.
Ballantyne2 stated that Sir William Gowers shortly thereafter, in an apparent misquote of Gunn, called the same change silver wire. Although silver and copper wire were therefore originally used to describe the same arterial change, Ballantyne clarified their usage today as follows: 1. Copper wire—a term used to describe beginning sclerosis of an artery. The wall becomes less transparent and the vessel pale. The artery is increased in diameter, is tortuous, and has a more brilliant central light reflex. 2. Silver wire—a term used to describe advanced sclerosis of an artery. The sheathing
WISE GN. Retinal Arteriosclerosis Secondary to Vein Obstruction. AMA Arch Ophthalmol. 1959;61(5):766-779. doi:10.1001/archopht.1959.00940090768013