What is Macular Epiretinal Membrane (MEM)?

The macular epiretinal membrane is a tissue that grows on the surface of the retina in the macular area, which is the fundamental area for vision. When this membrane contracts and wrinkles, it causes progressive deformation of the retina with consequent visual distortion.

Image of normal retina

Image of macular epiretinal membrane (retinography and scanner)


Initially, the patient perceives a slight distortion of images and undulation of straight lines. When the traction exerted by the epiretinal membrane increases on the macula, these symptoms worsen. The patient can also have blurred vision in the central region of the visual field.

Blurred central vision

Amsler Grid: Recommended for the self-assessment of distortion of central and paracentral vision, affected in diseases of the macula. Distorted Vision: Straight lines are perceived as undulated. Scotomas: Missing lines.


In the mildest cases, monitoring with periodic checks can be chosen. On the other hand, when the vision gets worse, images become distorted and the normal anatomy of the macula deteriorates, surgery must be considered.