Artikel
Alterations in the structure of the epiretinal membranes in PVR: assumptions and reality
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Autoren
Veröffentlicht: | 22. September 2004 |
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Gliederung
Text
Objective
Proliferative Vitreoretinopathy (PVR) is known to be the main cause for failure of the routine retinal detachment surgery. Our aim was to follow and document the changes in the ultrastructure of the epiretinal membranes in different stages of PVR.
Methods
Epiretinal membranes were taken during vitrectomy of 34 patients with different stages of PVR and further analysed with transmission and scanning electron microscopy, according to routine techniques. Patients were precisely ophtalmologically examined prior to operation and an OCT image of the fundus was made in all cases.
Results
In the relatively early stages of the disease (B-C1 stages) mainly retinal pigment epithelial (RPE) cells, fibroblasts and occasional glial cells were found. Moreover some of the RPE cells showed altered characteristics- limited number of pigment granules, changes in shape, clustering of mitochondrial complexes around the cell nucleus. In the extracellular matrix single collagen fibres -type II were observed. In contrast, the epiretinal membranes from the developed stages of PVR were comprised mostly of fibroblasts and considerably diminished number of RPE cells. Cells with marks of degenerations were generally found. Rough collagen bundles type I were seen in the matrix and the number of proteoglycan complexes was significantly enlarged.
Conclusions
Our results point out that epiretinal membranes in PVR are dynamic structures, constantly changing their cell and matrix composition with the progression of the disease. The morphological changes together with the clinical (OCT) data are important to consider when discussing the most appropriate therapeutical approach for each case.