Inflammation and the formation of epiretinal membranes

Abstract

SummaryIn this review of the literature evidence is provided from clinical, histological and experimental sources that inflammatory processes play a central role in the pathogenesis of contractile epiretinal membranes and proliferative vitreoretinopathy.

Natural History of Idiopathic Epiretinal Membrane in Eyes with Good Vision Assessed by Spectral-Domain Optical Coherence Tomography

“…A recent study reported a 3.0% incidence of this occurrence at 11.6 months on average [24]. This incidence rate is comparable to our results that identified 4 such cases among 62 eyes (6.5%) over a period of 24 months.…”

Predominance of MMP-1 and MMP-2 in Epiretinal and Subretinal Membranes of Proliferative Vitreoretinopathy

“…Both enzymes have similar substrate specificities but whilst MMP-9 is released within hours, MMP-2 is expressed 3-4 days after injury. This may explain the relative absence of MMP-9 and the widespread distribution of MMP-2 within retinal membranes, which are solely associated with chronic inflammation (Gilbert et al, 1988). MMP-2 may be found in inactive form in normal vitreous (Brown et al, 1994) and aqueous humour (Girolamo et al, 1996), and a recent study shows the presence of MMP-2 and TIMP-2 in vitreous from eyes with PVR and other vitreo-retinal disorders (De La Paz et al, 1998).…”

“…Retinal membranes are composed of retinal pigment epithelial cells, glial cells, astrocytes and fibroblasts (Gilbert et al, 1988 ;Jerdan et al, 1989), in addition to infiltrating macrophages and lymphocytes (Limb et al, 1993 ;Weller, Heimann and Wiedemann, 1988). All these cells are bound into a framework of extracellular matrix proteins composed of collagen, fibronectin, vitronectin and laminin (Rodriguez, Newsome and Machemer, 1981 ;Weller et al, 1991 ;Scheiffarth et al, 1988), which confers contractibility to retinal membranes.…”

“…PVR is associated with a classical inflammatory response characterised by production and release of cytokines and growth factors from activated cells (Gilbert et al, 1988 ;Limb et al, 1991). Once released into the local microenvironment, cytokines promote the generation and deposition of extracellular matrix, leading to the development of epiretinal membranes.…”

Evaluation of focal choroidal excavation in the macula using swept-source optical coherence tomography

“…It has been reported that inflammatory mediators promote fibrovascular growth in the setting of secondary ERM formation. 11 It could be possible that a prior intraocular inflammatory insult could result in eventual formation of focal choroidal scarring as well as ERM, resulting in the coexistence of both entities.…”