Retinal Conditions

Epiretinal Membrane (ERM)

An epiretinal membrane (ERM), also referred to as a macular pucker, is a thin layer of scar tissue that can form over top of the eye’s macula – the light-sensitive tissue at the centre of the retina responsible for detailed vision. This tissue (membrane) causes varying degrees of distortion and blurring to the central field of vision.

Typically, an epiretinal membrane only forms in one eye, but it is possible, over time, for epiretinal membranes to form in both eyes.

Symptoms of an Epiretinal Membrane

Patients with an epiretinal membrane may experience varying degrees of vision loss or blurred vision in the affected eye(s). Usually, this is painless.

Symptoms of an epiretinal membrane include:

  • Blurred vision.
  • Difficulty seeing fine detail and reading small print.
  • Double vision, including when one eye is closed.
  • The centre field of vision may appear distorted or blurry.
  • Appearance of a grey area or blind spot in the centre field of vision.

In some cases, the presence of an epiretinal membrane does not cause any noticeable change in vision. However, it is recommended that all patients diagnosed with an epiretinal membrane consult with their retinal specialist to determine if treatment is needed.

Causes of an Epiretinal Membrane

Epiretinal membranes can occur naturally as part of the aging process. As we age, the vitreous gel inside the eye slowly shrinks and pulls away from the surface of the retina. For some, the pull on the retina causes a small amount of damage. As it heals, a thin layer of scar tissue (an epiretinal membrane) forms on the retina’s surface. When this scar tissue forms over top of the macula, it blurs and distorts the detailed, central field of vision.

Epiretinal membranes commonly affect patients with no previous history of eye problems. However, there are higher risk groups for developing an epiretinal membrane; these include:

  • Adults over the age of 60
  • History of diabetic retinopathy, retinal detachment, retinal tear, retinal vein occlusion, or uveitis
  • Eye injury

Diagnosing an Epiretinal Membrane

The presence of an epiretinal membrane can be determined through a dilated eye exam using a slit lamp.

Since an epiretinal membrane can cause swelling and inflammation of the retina, your retinal specialist may recommend additional testing in order to measure the severity and monitor changes. Diagnostic tests commonly used in cases of epiretinal membranes include optical coherence tomography (OCT), fundus photography, and fluorescein angiography.

Treatment of an Epiretinal Membrane

If already diagnosed with an epiretinal membrane but there is little to no effect on vision, treatment may not be necessary. Future eye exams and testing may be needed in order to monitor any changes. It is always best to consult with your retinal specialist on what actions should be taken.

For patients with significantly noticeable vision loss and swelling of the retina, an epiretinal membrane peel in conjunction with vitrectomy surgery will likely be recommended. Surgery for removing an epiretinal membrane is typically not advised unless the level of vision loss is impairing the patient’s lifestyle. During this treatment, the epiretinal membrane will be gently removed from the macula in order to restore vision.