[Hyperplasia of the adventitional and mural reticulin fibers in diabetic retinopathy]

[Focal epiretinal fibroplasias overlying photocoagulations in diabetic retinopathy (author's transl)]

This clinico-pathological study compares photocoagulated diabetic retinae with cases of spontaneous epiretinal fibroplasia. Focal epiretinal fibroplasias were found overlying 5-10% of the Xenon-arc photocoagulations but not over Ruby-laser coagulations. These foci are contiguous-forming membranes but they do not cause surface wrinkling. The topography and appearance of the fibrous components of these membranes in trypsin-digest specimens are described and compared with foci of spontaneous epiretinal surface wrinkling. Destruction of the inner retinal surface by heavy coagulation is believed to be the principal cause of focal post-photocoagulation fibroplasia. Other possible pathogenetic factors are discussed.

Perivascular and intervascular reticular fibers of the retina

We demonstrated the existence in the retina of an argyrophilic perivascular membrane comparable in all respects to that which exists throughout the vascular system. We compared our findings by light microscopy with those previously reported. We identified, by electron microscopy, the normal general location of the network between the basal laminae of the glial and vessel cells and demonstrated its selective staining with silver methenamine. These perivascular fibers, intercapillary strands, and bridges develop in relation to the process of retinal vascularization and the potential for forming these fibers is reactivated in senility and disease, as in diabetes. We summarized the evidence by concluding that these fibers are most likely composed of reticulin; it appears provable that in the past there may have been some confusion with neural fibers.