Purchase this article with an account.
J. Hillenkamp, M. Kritzenberger, K. Kobuch, P. Saikia, C. Framme, H. Helbig, E. R. Tamm; Analysis of Structural and Molecular Differences Beween Idiopathic Epiretinal Membranes of the Cellophane and Non-Cellophane Type. Invest. Ophthalmol. Vis. Sci. 2007;48(13):3608.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate structural and molecular differences between idiopathic epiretinal membranes clinically classified as either of the cellophane or non-cellophane type.
Nine idiopathic epiretinal membranes (IEM; 4 cellophane type and 5 non-cellophane type) were fixed in Karnovsky and processed for transmission electron microscopy. For immunohistochemistry, 17 IEM (9 cellophane type and 8 non-cellophane type) were fixed in 4% paraformaldehyde, embedded in paraffin and stained with antibodies against collagens I, II, III, IV, VI, fibronectin, laminin, elastin, and smooth muscle α-actin.
Both types of IEM consisted of three layers: (1) an inner cellular layer, which was predominately populated by myofibroblast-like cells, (2) an intermediate layer, which contained dense extracellular fibrillar material and (3) the inner limiting membrane. Major differences between the two types of membranes were found in the intermediate layer of fibrillar extracellular material: In cellophane type IEM, the major fibril type was 8-12 nm in diameter without obvious periodicity. In contrast, in non-cellophane type IEM, most of the fibrils were considerably thicker with a diameter of 40-50 nm and the typical 68 nm periodicity of collagen fibrils. Occasionally, aggregates of long-spacing collagen with a periodicity of approximately 80 nm were observed. Immunohistochemistry showed the presence of laminin, fibronectin and various collagen types (I, III, IV, VI) in both types of IEM. Still, in cellophane type IEM, fibronectin was considerably more abundant than in non-cellophane type IEM. In contrast, collagen VI was stronger expressed in non-cellophane type IEM than in cellophane type IEM.
The different structure and molecular composition of an intermediate layer of fibrillar extracellular matrix very likely accounts for the different clinical appearance and the different mechanical properties of cellophane and non-cellophane like IEM.
This PDF is available to Subscribers Only