[Pathological basis for clinical stages of the proliferative process in diabetic retinopathy]

In order to elucidate the relationships between posterior ocular structures, 48 samples of epiretinal membranes were examined, which were obtained during transcilliary vitrectomy for proliferative diabetic retinopathy of different stages (29 patients with type I diabetes mellitus and 19 with type 2). The findings of morphological analysis and preoperative ophthalmoscopy (color photographs) demonstrated clinical and morphological correlations of stages of proliferative diabetic retinopathy. Impossibility of differential diagnosis between posterohyaloid membrane and newly formed tissue by clinical methods and impossibility of their mechanical intraoperative separation allow us to regard the stages of proliferative process as stages in changes of the posterohyaloid membrane proper. The posterohyaloid membrane is detected clinically and morphologically only in the presence of pathological changes, including diabetic retinopathy. We detected the following clinical histological correlations of proliferative process stages in diabetic retinopathy: 1) glial; 2) glio-vascular; 3) glio-vascular-fibrous; 4) fibrovascular; 5) fibrous (cicatricial). The histology of stages of proliferative diabetic retinopathy and correlation of histological findings with the clinical (ophthalmoscopic) picture of the process are described in detail. Recommendations on the treatment of each of these stages are offered.