According to the present concept, retinopathy implies manifestations in the fundus of hypertension ; renal disease ; diabetes ; retinal edema and exudates secondary to various forms of optic neuritis and papilledema; localized disease of blood vessels, such as Coats's disease (retinitis exudative) and von Hippel's disease (angiomatosis of the retina) ; senile degenerative disease of Bruch's membrane and choriocapillaris, and, finally, diseases of the blood.
Actually, all types of retinopathy are based on localized structural changes in the blood vessels and capillaries, irrespective of the cause. With the exception of tuberculosis of the vessels and angiomatosis, these changes in the blood vessels are produced by some type of blood dyscrasia, primary or secondary.
Since nutrition of the walls of small vessels and capillaries depends on the quality as well as the quantity of the blood within, qualitative or quantitative reduction results in degenerative changes. In cases of early hypertension with localized quantitative reduction,