{'fraction_non_alphanumeric': 0.017227877838684416, 'fraction_numerical': 0.0015661707126076742, 'mean_word_length': 5.295566502463054, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
[Alterations in the structure of the epiretinal membranes in PVR -- assumptions and reality].

BACKGROUND
Proliferative vitreoretinopathy (PVR) is known to be the main cause of failure for routine retinal detachment surgery. Our aim was to document the ultrastructural changes in the epiretinal membranes in cases of PVR.


MATERIAL AND METHODS
Epiretinal membranes were taken during vitrectomy of 64 patients with different stages of PVR and further analysed using transmission and scanning electron microscopy.


RESULTS
In the early stages of the disease mainly retinal pigment epithelial (RPE) cells, fibroblasts and occasional glial cells were found. Moreover, some of the RPE cells showed altered characteristics. In contrast, epiretinal membranes from the developed stages of PVR were comprised mostly of fibroblasts and a considerably diminished number of RPE cells. Cells with marks of degeneration were generally found.


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 data are important points to consider when discussing the most appropriate therapeutic approach for each case.