[Histopathological study of epiretinal membranes in retinopathy of prematurity].

Objective: To study the pathological characteristics of epiretinal membranes (ERMs) in retinopathy of prematurity (ROP), and to discuss the pathogenesis of ROP.

Methods: It was a retrospective case series. Thirty-four ERMs obtained from twenty-four patients with stage 5 ROP during open-sky vitrectomy were examined by light microscopy (HE staining). Fifteen ERMs of them were examined by transmission electron microscopy. Glial fibrillary acidic protein staining (GFAP) of two ERMs were observed. Spearman rank correlation analysis of SPSS 11.0 software and random-effects model of STATA 7.0 software were used to make statistical analysis.

Results: Collagen was the main component of the ERMs. The amount of neovascularization was highly correlated with the age and postconceptual age (r = - 0.469, -0.482; P <0.05, respectively), but no statistically significant correlation with the gestational age and birth weight (r = - 0.179, - 0.272; P > 0.05). The amount of the fibroblasts varied in different specimens. It was related to the gestational age, age and postconceptual age (Z = -1.99, -3.45, -3.64; P <0.05). No obvious relationship was found between the amount of the fibroblasts and the birth weight (Z = 0.21, P > 0.05). Electron microscopy showed a wide variety of cell types, which scattered in the ERMs, including fibroblasts, myofibroblasts, vascular endothelial cells, macrophages and other inflammatory cells. GFAP staining of the ERMs was positive, and staining positive cells were mostly distributed on the retinal side of the ERMs.

Conclusions: Fibroblasts and myofibroblasts were the main cells of the ERM of ROP. The regression of the ERM of ROP was correlated to the actual age and postconceptual age, and it had no relationship with the birth weight. The glial cells played an important role in the progression of ROP.