Epiretinal Membrane – or Macula Pucker

Epiretinal membranes, also commonly known as macular puckers, are semitranslucent, fibrocellular membranes that form on the inner surface of the retina.

Most patients with ERMs have no symptoms; their ERMs are found incidentally on dilated retinal exam or on retinal imaging with optical coherence tomography (OCT). In such cases, patients typically have normal or near-normal vision. 

However, ERMs can slowly progress, causing a visual distortion in which straight objects such as door frames and window blinds become crooked. In more severe cases, vision can be significantly decreased.

Causes

The cause of ERMs is due to a defect in the surface layer of the retina where a type of cell, called glial cells, can migrate through and start to grow in a membranous sheet on the retinal surface. This membrane looks like a layer of saran wrap and over time may contract and cause traction (or pulling) and puckering of the retina, leading to decreased vision and metamorphopsia.

The most common cause of macular pucker is an age-related condition called posterior vitreous detachment (PVD), where the vitreous gel that fills the eye separates from the retina causing symptoms of floaters and flashes. If there is no specific cause apart from the PVD, the ERM is called idiopathic (of unknown origin).

ERMs can be associated with a number of ocular conditions such as prior retinal tears or detachment, retinal vascular diseases such as diabetic retinopathy or venous occlusive disease; they can also be post-traumatic, occuring following ocular surgery, or be associated with intraocular (inside the eye) inflammation.

Diagnostics and Treatment

An OCT scan clearly identifies the pucker layer on the surface of the retina.

Most ERM’s cause no or minimal symptoms and need only to be monitored.

In more advanced cases where distortion and decreased vision occurs, an intraocular surgery called a vitrectomy is required in which the vitreous gel is removed and the membranous pucker layer is peeled away.

They most commonly cause minimal symptoms and can be simply observed, but in some cases they can result in painless loss of vision and metamorphopsia (visual distortion). Generally, ERMs are most symptomatic when affecting the macula, which is the central portion of the retina that helps us to distinguish fine detail used for reading and recognizing faces.

Epiretinal membrane