An Epiretinal Membrane (ERM) is a layer of fibrous tissue that forms on the innermost layer of the retina of the eye, known as the internal limiting membrane. The development of this scar tissue occurs over the surface of the macula, which is an oval spot near the center of the retina, involved in sharp focus of vision.
What are the other Names for this Condition? (Also known as/Synonyms)
- Cellophane Maculopathy
- ERM (Epiretinal Membrane)
- Surface Wrinkling Retinopathy
What is Epiretinal Membrane? (Definition/Background Information)
- An Epiretinal Membrane (ERM) is a layer of fibrous tissue that forms on the innermost layer of the retina of the eye, known as the internal limiting membrane. The development of this scar tissue occurs over the surface of the macula, which is an oval spot near the center of the retina, involved in sharp focus of vision
- The condition is more common in middle aged and elderly adults, when compared to younger populations. Advancing age, cataract surgery, certain pre-existing conditions, such as diabetes that can cause eye disease, retinal detachment, and injury to the eye are a few risk factors for the development of Epiretinal Membrane
- ERM can occur spontaneously, or as a response to trauma, surgery, or traction on the retina of the eye. Additionally, if the individual already has the condition in one eye, he/she is more likely to develop it in the other eye as well
- Epiretinal Membrane is usually asymptomatic, but can cause vision difficulties including blurred/distorted vision and reduced sight, due to the abnormal tissue covering the macula. Potential complications include the formation of a hole in the macula or in the ERM
- In many cases, Epiretinal Membrane is observed and monitored closely by the healthcare provider. If the condition affects vision acuity, surgery is recommended. The surgical procedure involves peeling-off the membrane, after addressing the underlying issue. Typically, the prognosis is excellent, in a majority of individuals, even when surgery is required to remove the protective membrane
- Currently, Epiretinal Membrane is an eye disorder that cannot be prevented. Nevertheless, if it is caused by an underlying condition, such as poorly-controlled diabetes; then, managing the condition may help prevent such pathological changes in the eye
Who gets Epiretinal Membrane? (Age and Sex Distribution)
- Epiretinal Membrane is a relatively common disorder, occurring in about 7% of the population.
- It is more common in middle-aged and older adults
- The prevalence of ERM increases with age. Studies indicate that about 2% of adults older than 50 years of age, and nearly 20% of adults older than 75 years may be affected
- The condition can occur in both genders. However, it is slightly more common in females than males (3:2 female-male ratio)
- There is no specific racial and ethnic group predilection observed
What are the Risk Factors for Epiretinal Membrane? (Predisposing Factors)
The risk factors for developing Epiretinal Membrane may include:
- Posterior vitreous detachment
- Retinal tear/detachment
- Injury or trauma to the eye (ocular trauma)
- Intraocular surgery, such as cataract surgery
- Retinal vascular diseases (i.e. diabetic retinopathy, artery/vein occlusions)
- The presence of Epiretinal Membrane in one eye, places one at a higher risk of developing the condition in the other eye
It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.
Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.
What are the Causes of Epiretinal Membrane? (Etiology)
Epiretinal Membrane, in most cases, develops spontaneously. No apparent association with a history/background of medical conditions is noted. In such cases, the eye disorder is known as Idiopathic Epiretinal Membrane.
ERM can also be caused by a variety of factors including:
- Trauma: This may occur owing to intra-ocular surgery, or other factors resulting in injury to the retina. This is called Traumatic Epiretinal Membrane
- Traction: It is the pulling of the vitreous humor from the retina, causing distortion
- The vitreous humor is a gel-like substance inside the eye. The gel is encased in a structure, called the vitreous cortex, which is attached to the retina
- With age, or due to some diseases, the cortex starts pulling away from the retina. This is called posterior vitreous detachment (PVD)
- If the detachment is incomplete, the vitreous cortex may pull at the retina due to tractional forces, resulting in retinal changes or abnormalities. This condition is known as vitreo-macular traction (VMT)
Under certain circumstances (such as the above), when the retina needs protection, certain cells such as the residual glial cells, from the back of the vitreous gel, proliferate and form a membrane over the internal limiting membrane of the retina, usually over the macula. This abnormal development of fibrous tissue layer/membrane is known as Epiretinal Membrane.
- The macula is near the center of the retina, and is involved in sharp focusing functions
- Glial cells are not nerve cells, but play crucial supportive and protective roles
Apart from glial cells, retinal pigment epithelial cells, astrocytes, fibrocytes and macrophages may also be found in the protective membrane.
What are the Signs and Symptoms of Epiretinal Membrane?
The signs and symptoms due to Epiretinal Membrane vary from one individual to another. ERM is usually asymptomatic, but may present with the following symptoms, in some cases:
- Decreased vision
- Distorted vision
- Loss of central vision
- Blurred vision
- Double vision in one eye (monocular diplopia)
- Wavy vision
- Difficulty in reading small print
How is Epiretinal Membrane Diagnosed?
The diagnosis of Epiretinal Membrane is undertaken by the following methods:
- An assessment of symptoms
- Understanding the medical history of the affected individual, with respect to underlying diseases, if any
- Evaluating the history of posterior vitreous detachment, intraocular surgery, or trauma
- Eye examination: An observation of the membrane on the surface of the macula upon fundus examination may reveal:
- Fine, shiny membrane over the macula
- More advanced Epiretinal Membrane appearing as a thick, gray-white membrane
- Optical coherence tomography (OCT): It is an imaging technique that helps visualize the eye structure. This tool provides 3-dimensional images of soft biological tissues such as the retina, optic nerve, arteries, etc. The ERM can be seen over the internal limiting membrane of the retina
Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.
What are the possible Complications of Epiretinal Membrane?
Some potential complications of Epiretinal Membrane include:
- Decreased and/or distorted vision causing significant vision problems and emotional stress
- Macular hole; if continued vitreo-macular traction occurs after formation of ERM
- Macular pseudohole: It is a hole that forms in the Epiretinal Membrane over the macula, rather than in the macula itself
- Surgical complications such as bleeding, retinal detachment, infection, and recurrence of ERM
- Early cataract
How is Epiretinal Membrane Treated?
The treatment measures for Epiretinal Membrane include:
- Monitoring, especially if vision is unaffected, or remains better than 20/40
- Surgery: After removal of the vitreous via vitrectomy, the Epiretinal Membrane is peeled-off with a surgical instrument
How can Epiretinal Membrane be Prevented?
- Presently, no methods or guidelines exist for the prevention of Epiretinal Membrane
- In the case of secondary Epiretinal Membranes resulting from other vitreous or retinal diseases (such as diabetic retinopathy), managing the systemic disease can help prevent the condition
What is the Prognosis of Epiretinal Membrane? (Outcomes/Resolutions)
The prognosis for Epiretinal Membrane is excellent in a majority of individuals.
- If decreased vision occurs due to Epiretinal Membrane, it is usually visually insignificant and does not affect one’s daily activities or quality of life sufficiently enough to warrant a surgical treatment
- Surgical membrane-peeling procedure, for more advanced cases of ERM, usually improves vision in the affected eye significantly
Additional and Relevant Useful Information for Epiretinal Membrane:
- Epiretinal Membrane peeling surgery is the most common vitreoretinal surgery performed
- A surgery is often not undertaken, due to the risks of surgical complications far outweighing the potential small increase in visual acuity, for mild cases
- The severity of ERM upon observation during fundus (eye) examination, does not always correlate with a severity of decreased vision
What are some Useful Resources for Additional Information?
American Optometric Association
243 N. Lindbergh Boulevard St. Louis, MO 63141
Toll-Free: 1 (800) 365-2219
References and Information Sources used for the Article:
http://eyewiki.aao.org/Epiretinal_Membrane (accessed on 03/15/17)
Friedman, N. Kaiser, J. The Massachusetts Eye and Ear Infirmary. 3rd Edition. Elsevier, 2009.
Rapuano, Christopher J. Heng, Wee-Jin. Color Atlas and Synopsis of Clinical Ophthamology. Wills Eye Hospital. Singapore: McGraw-Hill, 2003.
Helpful Peer-Reviewed Medical Articles:
Thompson JT (2004). Vitrectomy for epiretinal membranes with good visual acuity. Transactions of the American Ophthamological Society.
Grewing R, Mester U (1996). Results of surgery for epiretinal membranes and their recurrences. British Journal of Ophthamology.
Park SS, Choi SS, Zawadzki RJ, Werner JS (2009). Fine retinal striae associated with epiretinal membrane visualized using adaptive optics. Retina Cases Brief Rep.
Chuang LH, Wang NK, Chen YP, Hwang YS, Chen JK, Yeung L, Wu WC, Chen TL, Lai CC (2012). Comparison of visual outcomes after epiretinal membrane surgery. Taiwan Journal of Ophthamology.
Stevenson W, Prospero Ponce CM, Agarwal DR, Gelman R, Christoforidis JB (2016). Epiretinal membrane: optical coherence tomography-based diagnosis and classification. Clinical Ophthamology.
Scheerlinck LM, van der Valk R, van Leeuwen R (2014). Predictive factors for postoperative visual acuity in idiopathic epiretinal membrane: a systematic review. Acta Ophthamologica.
Rizzo, S., Genovesi-Ebert, F., Murri, S., Belting, C., Vento, A., Cresti, F., & Manca, M. L. (2006). 25-gauge, sutureless vitrectomy and standard 20-gauge pars plana vitrectomy in idiopathic epiretinal membrane surgery: a comparative pilot study. Graefe's Archive for Clinical and Experimental Ophthalmology, 244(4), 472-479.
Kadonosono, K., Yamakawa, T., Uchio, E., Yanagi, Y., Tamaki, Y., & Araie, M. (2006). Comparison of visual function after epiretinal membrane removal by 20-gauge and 25-gauge vitrectomy. American journal of ophthalmology, 142(3), 513-515.
Tadayoni, R., Paques, M., Massin, P., Mouki-Benani, S., Mikol, J., & Gaudric, A. (2001). Dissociated optic nerve fiber layer appearance of the fundus after idiopathic epiretinal membrane removal. Ophthalmology, 108(12), 2279-2283.
Falkner-Radler, C. I., Glittenberg, C., Hagen, S., Benesch, T., & Binder, S. (2010). Spectral-domain optical coherence tomography for monitoring epiretinal membrane surgery. Ophthalmology, 117(4), 798-805.
Shimozono, M., Oishi, A., Hata, M., Matsuki, T., Ito, S., Ishida, K., & Kurimoto, Y. (2012). The significance of cone outer segment tips as a prognostic factor in epiretinal membrane surgery. American journal of ophthalmology, 153(4), 698-704.
Haas, A., Seidel, G., Steinbrugger, I., Maier, R., Gasser-Steiner, V., Wedrich, A., & Weger, M. (2010). Twenty-three-gauge and 20-gauge vitrectomy in epiretinal membrane surgery. Retina, 30(1), 112-116.