A previous report from this laboratory concerned the histologic abnormalities in the vessels of diabetic retinopathy.1 The present report is concerned with the extravascular changes. These extravascular lesions of diabetic retinopathy consist of hemorrhages and a miscellany of hyalinelipid material that both clinicians and pathologists have called exudate. The implication has been that the vessels have become leaky as a result of arteriolar obstruction or pathologic changes in the vessel walls and that the extravascular material is serum or material derived from serum.
It was the purpose of the present study to document the histopathologic changes on the basis of material at our disposal, to reassess the evidence of an exudative basis for the accumulation of abnormal material in the retina, and to correlate the occurrence of these deposits with the vascular changes. The subject of hemorrhages has been omitted from this discussion since it has been abundantly described
TOUSSAINT D, COGAN DG, KUWABARA T. Extravascular Lesions of Diabetic Retinopathy. Arch Ophthalmol. 1962;67(1):42-47. doi:10.1001/archopht.1962.00960020044007