Epiretinal membranes are the result of cellular proliferation along the internal limiting membrane and retinal surface. They are hypo-cellular largely collagen structures and can be either idiopathic or secondary. They vary in severity from very subtle membranes to thick membranes covering the macular region.
The so-called idiopathic type of epimacular membrane has been shown to be caused by glial proliferation through a defect in the internal limiting lamina, usually created by a posterior vitreous separation. Secondary causes include retinal vascular occlusions, diabetic retinopathy, the aftermath of surgical procedures such as like retinal detachment surgery, ocular inflammatory conditions and the after-effects of laser or cryotherapy.
Contraction of these membranes causes retinal wrinkling and several types...