Abstract
Purpose:
The first aim of this study was to assess a possible relation between etiologic and histological types of epiretinal membranes. Furthermore the second objective was to analyse a correlation between evolution and etiology or histological type.
Methods:
64 eyes which went under pars plana vitrectomy by the same surgeon between january 2010 and december 2011 were studied. Patients were splited up into three main groups according to clinical features that led to surgical indication: idiopathic epiretinal membranes, fibrovascular membranes of proliferative diabetic retinopathy, and proliferative vitreoretinopathy (PVR) membranes. Removed tissue during surgery was fixated and evaluated by light microscopy under hematoxylin eosin staining. 19 eyes were excluded because of insufficient material. The remaining 45 samples were then divided into three groups according to the amount of pigment presented and grade of cellularity: A, no pigment present and scarce cellularity; B, scarce pigment and moderate cellularity; C, abundant pigment and cellularity. Evolution was recorded considering onset of symptoms and time of surgery.
Results:
20 eyes (44%) were classified as PVR, 16 were idiopathic (36%) and 9 were diabetic retinopathy membranes (20%). Among the PVR etiology, 9 tissue samples (45%) were labeled as histological type B, 7 (35%) as type A, and 4 (20%) as type C; in the idiopathic group, 13 samples (81%) were included in type A group, 2 (13%) in type B, and 1 (6%) in group C; while in PVR patients 4 (44%) were type A, 4 (44%) were type B, and 1 (11%) was type C. No stadistical significant correlation was found between etiologic and histologic types of epiretinal membranes. 15 eyes (94%) of the idiopathic membranes eyes, 8 (89%) of the diabetic retinopathy patients, and 8 (40%) of PVR eyes had symptoms for more than 4 months until surgery. Median evolution for group A was 12.17 months, 8.07 months for group B, and and 4.7 months for group C.
Conclusions:
No significant correlation was found between histological type of membranes and etiology. Idiopatic and diabetic membranes had more frecuently symptoms longer than 4 months until surgery was applied, while PVR patients were operated up to 4 months from onset of symptoms in the majority of cases. There was a positive correlation between samples with long evolution and its less amount of pigment and cellularity.
Keywords: 688 retina •
762 vitreoretinal surgery •
599 microscopy: light/fluorescence/immunohistochemistry