Simple diabetic retinopathy. Evolution of the lesions and therapeutic considerations.

The name Simple (or Exudative) Diabetic Retinopathy includes a variety of diabetic changes, in particular, lipoid exudates, microaneurysms, and haemorrhages. The term specifically excludes cases in which new vessel formations are present: Proliferative or Malignant Diabetic Retinopathy (Burditt, Caird, and Draper, I968). Simple diabetic retinopathy shows a marked tendency to be symmetrical and to involve the posterior poles of the eyes; for this reason the term Diabetic Maculopathy is sometimes applied. The lipoid exudates constitute the most obvious clinical sign, but the more fundamental lesions are small islets of pathological capillaries in which microaneurysms are the most easily observed elements. These changes in the minute vessels usually precede the lipoid changes and it is the deposition of lipoid and oedematous changes in the macular area which cause the risk of the loss of central vision. The present investigation has two aims in view: (i) To examine the spontaneous changes in exudates and foci of capillary damage which take place over a period of several years, for only by a knowledge of these changes can the effect of therapy be assessed.