Idiopathic Epiretinal Membrane and Vitreomacular Traction Preferred Practice Pattern®

Protecting Sight. Empowering Lives.® AMERICAN ACADEMY OF OPHTHALMOLOGY® © 2019 by the American Academy of Ophthalmology Published by Elsevier Inc. http://dx.doi.org/10.1016/j.ophtha.2019.09.022 ISSN 0161-6420/19 Secretary for Quality of Care Timothy W. Olsen, MD Academy Staff Ali Al-Rajhi, PhD, MPH Andre Ambrus, MLIS Meghan Daly Flora C. Lum, MD Medical Editor: Susan Garratt Approved by: Board of Trustees September 7, 2019 © 2019 American Academy of Ophthalmology® All rights reserved AMERICAN ACADEMY OF OPHTHALMOLOGY and PREFERRED PRACTICE PATTERN are registered trademarks of the American Academy of Ophthalmology. All other trademarks are the property of their respective owners. Preferred Practice Pattern® guidelines are developed by the Academy's H. Dunbar Hoskins Jr., MD Center for Quality Eye Care without any external financial support. Authors and reviewers of the guidelines are volunteers and do not receive any financial compensation for their contributions to the documents. The guidelines are externally reviewed by experts and stakeholders before publication. Correspondence: Ali A. Al-Rajhi, PhD, MPH, American Academy of Ophthalmology, P. O. Box 7424, San Francisco, CA 94120-7424. E-mail: [email protected]. The Retina/Vitreous Preferred Practice Pattern® Panel members wrote the Idiopathic Epiretinal Membrane and Vitreomacular Traction Preferred Practice Pattern® (PPP) guidelines. The PPP Panel members discussed and reviewed successive drafts of the document, meeting in person twice and conducting other review by e-mail discussion, to develop a consensus over the final version of the document. Retina/Vitreous Preferred Practice Pattern Panel 2018–2019 Ron A. Adelman, MD, MPH, MBA, FACS Steven T. Bailey, MD, Retina Society Representative Amani Fawzi, MD, Macula Society Representative Jennifer I. Lim, MD Gurunadh A. Vemulakonda, MD, American Society of Retina Specialists Representative Gui-shang Ying, MD, PhD, Methodologist Christina J. Flaxel, MD, Chair We thank our partners, the Cochrane Eyes and Vision US Satellite ([email protected]), for identifying reliable systematic reviews that we cite and discuss in support of the PPP recommendations. The Preferred Practice Patterns Committee members reviewed and discussed the document during a meeting in June 2019. The document was edited in response to the discussion and comments. Preferred Practice Patterns Committee 2019 Robert S. Feder, MD, Chair Roy S. Chuck, MD, PhD Steven P. Dunn, MD Christina J. Flaxel, MD Steven J. Gedde, MD Francis S. Mah, MD Randall J. Olson, MD David K. Wallace, MD, MPH David C. Musch, PhD, MPH, Methodologist The Idiopathic Epiretinal Membrane and Vitreomacular Traction PPP was then sent for review to additional internal and external groups and individuals in July 2019. All those returning comments were required to provide disclosure of relevant relationships with industry to have their comments considered (indicated with an asterisk below). Members of the Retina/Vitreous Preferred Practice Pattern Panel reviewed and discussed these comments and determined revisions to the document. In compliance with the Council of Medical Specialty Societies' Code for Interactions with Companies (available at www.cmss.org/codeforinteractions.aspx). relevant relationships with industry are listed. The Academy has Relationship with Industry Procedures to comply with the Code (available at http://one.aao.org/CE/PracticeGuidelines/PPP.aspx). A majority (100%) of the members of the Retina/Vitreous Preferred Practice Pattern Panel 2018–2019 had no financial relationship to disclose. Retina/Vitreous Preferred Practice Pattern Panel 2018–2019 Christina J. Flaxel, MD: No financial relationships to disclose Ron A. Adelman, MD, MPH, MBA, FACS: No financial relationships to disclose Steven T. Bailey, MD: No financial relationships to disclose Amani Fawzi, MD: No financial relationships to disclose Jennifer I. Lim, MD: No financial relationships to disclose Gurunadh A. Vemulakonda, MD: No financial relationships to disclose Gui-shang Ying, MD, PhD: No financial relationships to disclose Preferred Practice Patterns Committee 2019 Robert S. Feder, MD, Chair: No financial relationships to disclose Roy S. Chuck, MD, PhD: Novartis—Consultant/Advisor Steven P. Dunn, MD: No financial relationships to disclose Christina J. Flaxel, MD: No financial relationships to disclose Steven J. Gedde, MD: No financial relationships to disclose Francis S. Mah, MD Novartis—Consultant/Advisor & Lecture Fees Randall J. Olson, MD: No financial relationships to disclose David K. Wallace, MD, MPH: No financial relationships to disclose David C. Musch, PhD, MPH, Methodologist: IRIDEX, Notal Vision—Consultant/Advisor Secretary for Quality of Care Timothy W. Olsen, MD: No financial relationships to disclose Academy Staff Ali Al-Rajhi, PhD, MPH: No financial relationships to disclose Andre Ambrus, MLIS: No financial relationships to disclose Meghan Daly: No financial relationships to disclose Flora C. Lum, MD: No financial relationships to disclose The disclosures of relevant relationships to industry of other reviewers of the document from January to October 2019 are available online at www.aao.org/ppp. OBJECTIVES OF PREFERRED PRACTICE PATTERN GUIDELINES P151METHODS AND KEY TO RATINGS P152HIGHLIGHTED FINDINGS AND RECOMMENDATIONS FOR CARE P153INTRODUCTION P154Disease Definition P154Patient Population P154Clinical Objectives P154BACKGROUND P154Incidence and Prevalence P155Risk Factors P156Pathogenesis of Epiretinal Membrane and Vitreomacular Traction P157Epiretinal Membrane P157Vitreomacular Traction P157CARE PROCESS P158Patient Outcome Criteria P158Diagnosis P158History P158Examination P158Diagnostic Tests P159Ancillary Tests P162Management P162Nonsurgical P162Observation without Treatment P162Surgery P163Follow-up Evaluation after Surgery P172Provider and Setting P172Counseling and Referral P173Socioeconomic Considerations P173APPENDIX 1. QUALITY OF OPHTHALMIC CARE CORE CRITERIA P174APPENDIX 2. INTERNATIONAL STATISTICAL CLASSIFICATION OF DISEASES AND RELATED HEALTH PROBLEMS (ICD) CODES P176LITERATURE SEARCHES FOR THIS PPP P177RELATED ACADEMY MATERIALS P177REFERENCES P178 Background: Epiretinal membrane (ERM) and vitreomacular traction (VMT) are relatively common retinal conditions that are predominant in adults. VMT is less common than ERM and affects an estimated 0.4% to 2.0%. Idiopathic ERM is estimated to occur in approximately 30 million adults in the United States 43 to 86 years old. Prevalence for ERMs range from a low of 2.2% and 3.4% (Beijing Eye Study and Handan Eye Study, respectively), to a high of 18.8% and even 28.9% among Latinos in Los Angeles and in a multi-ethnic study conducted in 6 communities in the United State (MESA). Risk factors for ERM is most common in individuals with retinal pathology (e.g., uveitis and other ocular inflammatory diseases) and cataract surgery; and may be associated with impaired visual acuity. Patients with VMT have similar symptoms of impaired visual function and metamorphopsia that may be acute or chronic depending on the severity of the traction and the resulting distortion or detachment of the macula. The recommendations of this Preferred Practice Pattern are based on Cochrane-identified reliable systematic reviews. Rationale for treatment: A majority of ERMs will remain relatively stable without treatment. However, a successful surgical procedure is available that could address worsening symptoms. Periodical tests of the patient's central vision monocularly should be encouraged to detect changes that may occur over time. Care Process: Patient outcome criteria are to prevent vision loss and functional impairment, optimize visual function, minimize symptoms (e.g., metamorphosia, diplopia), and maintain or improve quality of life. Initially spectral domain optical coherence tomography (SD-OCT) is used to diagnose and characterize ERM, VMT, and associated retinal changes. Vitrectomy surgery is often indicated in affected patients with a decrease in visual acuity, metamorphopsia, double vision, or difficulty using their eyes together. Vitrectomy for ERM or VMT usually leads to improvement of the metamorphopsia. On average, approximately 80% of patients with ERM or VMT will improve by at least 2 lines of visual acuity following vitrectomy surgery. Educating patients about the signs and symptoms of progression and regular monocular Amsler grid testing are both important. Although the visual acuity rarely improves spontaneously, it may worsen. As a service to its members and the public, the American Academy of Ophthalmology has developed a series of Preferred Practice Pattern® guidelines that identify characteristics and components of quality eye care. Appendix 1 describes the core criteria of quality eye care. The Preferred Practice Pattern® guidelines are based on the best available scientific data as interpreted by panels of knowledgeable health professionals. In some instances, such as when results of carefully conducted clinical trials are available, the data are particularly persuasive and provide clear guidance. In other instances, the panels have to rely on their collective judgment and evaluation of available evidence. These documents provide guidance for the pattern of practice, not for the care of a particular individual. While they should generally meet the needs of most patients, they cannot possibly best meet the needs of all patients. Adherence to these PPPs will not ensure a successful outcome in every situation. These practice patterns should not be deemed inclusive of all proper methods of care or exclusive of other methods of care reasonably directed at obtaining the best results. It may be necessary to approach different patients' needs in different ways. The physician must make the ultimate judgment about the propriety of the care of a particular patient in light of all of the circumstances presented by that patient. The American Academy of Ophthalmology is available to assist members in resolving ethical dilemmas that arise in the course of ophthalmic practice. Preferred Practice Pattern® guidelines are not medical standards to be adhered to in all individual situations. The Academy specifically disclaims any and all liability for injury or other damages of any kind, from negligence or otherwise, for any and all claims that may arise out of the use of any recommendations or other information contained herein. References to certain drugs, instruments, and other products are made for illustrative purposes only and are not intended to constitute an endorsement of such. Such material may include information on applications that are not considered community standard, that reflect indications not included in approved US Food and Drug Administration (FDA) labeling, or that are approved for use only in restricted research settings. The FDA has stated that it is the responsibility of the physician to determine the FDA status of each drug or device he or she wishes to use, and to use them with appropriate patient consent in compliance with applicable law. Innovation in medicine is essential to ensure the future health of the American public, and the Academy encourages the development of new diagnostic and therapeutic methods that will improve eye care. It is essential to recognize that true medical excellence is achieved only when the patients' needs are the foremost consideration. All Preferred Practice Pattern® guidelines are reviewed by their parent panel annually or earlier if developments warrant and updated accordingly. To ensure that all PPPs are current, each is valid for 5 years from the approved by date unless superseded by a revision. Preferred Practice Pattern guidelines are funded by the Academy without commercial support. Authors and reviewers of PPPs are volunteers and do not receive any financial compensation for their contributions to the documents. The PPPs are externally reviewed by experts and stakeholders, including consumer representatives, before publication. The PPPs are developed in compliance with the Council of Medical Specialty Societies' Code for Interactions with Companies. The Academy has Relationship with Industry Procedures (available at www.aao.org/about-preferred-practice-patterns) to comply with the Code. Appendix 2 contains the International Statistical Classification of Diseases and Related Health Problems (ICD) codes for the disease entities that this PPP covers. The intended users of the Diabetic Retinopathy PPP are ophthalmologists. Preferred Practice Pattern® guidelines should be clinically relevant and specific enough to provide useful information to practitioners. Where evidence exists to support a recommendation for care, the recommendation should be given an explicit rating that shows the strength of evidence. To accomplish these aims, methods from the Scottish Intercollegiate Guideline Network1Steel DH Lotery AJ Idiopathic vitreomacular traction and macular hole: a comprehensive review of pathophysiology, diagnosis, and treatment.Eye (Lond). 2013; 27: S1-21Crossref PubMed Scopus (132) Google Scholar (SIGN) and the Grading of Recommendations Assessment, Development and Evaluation2Guyatt GH Oxman AD Vist GE et al.GRADE: an emerging consensus on rating quality of evidence and strength of recommendations.BMJ. 2008; 336: 924-926Crossref PubMed Google Scholar (GRADE) group are used. GRADE is a systematic approach to grading the strength of the total body of evidence that is available to support recommendations on a specific clinical management issue. Organizations that have adopted GRADE include SIGN, the World Health Organization, the Agency for Healthcare Research and Policy, and the American College of Physicians.3Suh MH Seo JM Park KH Yu HG Associations between macular findings by optical coherence tomography and visual outcomes after epiretinal membrane removal.Am J Ophthalmol. 2009; 147 (e473.): 473-480Abstract Full Text Full Text PDF PubMed Scopus (202) Google Scholar ♦All studies used to form a recommendation for care are graded for strength of evidence individually, and that grade is listed with the study citation.♦Tabled 1I++High-quality meta-analyses, systematic reviews of randomized controlled trials (RCTs), or RCTs with a very low risk of biasI+Well-conducted meta-analyses, systematic reviews of RCTs, or RCTs with a low risk of biasI-Meta-analyses, systematic reviews of RCTs, or RCTs with a high risk of biasII++High-quality systematic reviews of case-control or cohort studiesHigh-quality case-control or cohort studies with a very low risk of confounding or bias and a high probability that the relationship is causalII+Well-conducted case-control or cohort studies with a low risk of confounding or bias and a moderate probability that the relationship is causalII-Case-control or cohort studies with a high risk of confounding or bias and a significant risk that the relationship is not causalIIINonanalytic studies (e.g., case reports, case series) Open table in a new tab ♦Tabled 1Good qualityFurther research is very unlikely to change our confidence in the estimate of effectModerate qualityFurther research is likely to have an important impact on our confidence in the estimate of effect and may change the estimateInsufficient qualityFurther research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate Any estimate of effect is very uncertain Open table in a new tab ♦Tabled 1Strong recommendationUsed when the desirable effects of an intervention clearly outweigh the undesirable effects or clearly do notDiscretionary recommendationUsed when the trade-offs are less certain—either because of low-quality evidence or because evidence suggests that desirable and undesirable effects are closely balanced Open table in a new tab ♦The Highlighted Findings and Recommendations for Care section lists points determined by the PPP Panel to be of particular importance to vision and quality of life outcomes.♦All recommendations for care in this PPP were rated using the system described above. Ratings are embedded throughout the PPP main text in italics. Literature searches to update the PPP were undertaken in April 2018 and June 2019 in PubMed and the Cochrane Library. Complete details of the literature searches are available online at www.aao.org/ppp. Risk factors for epithelial membrane (ERM) include increasing age, other retinal pathologies (e.g., posterior vitreous detachment [PVD]), uveitis, retinal breaks, retinal vein occlusions, diabetic retinopathy4Bu SC Kuijer R Li XR Hooymans JM Los LI Idiopathic epiretinal membrane.Retina. 2014; 34: 2317-2335Crossref PubMed Scopus (125) Google Scholar, 5Cheung N Tan SP Lee SY et al.Prevalence and risk factors for epiretinal membrane: the Singapore Epidemiology of Eye Disease study.Br J Ophthalmol. 2017; 101: 371-376PubMed Google Scholar, and ocular inflammatory diseases). The majority of ERMs will remain relatively stable and do not require therapy. In patients who have areas of vitreomacular traction (VMT) of 1500 μm or less, the incidence of spontaneous release of traction from the macula occurs in approximately 30% to 40% of eyes over a follow-up of 1 to 2 years. Spectral-domain optical coherence tomography (SD-OCT) is a highly sensitive and routine methodology used to diagnose and characterize ERM, VMT, and associated retinal changes. Vitrectomy surgery is often indicated in affected patients who have a decrease in visual acuity, metamorphopsia, double vision, or difficulty using their eyes together. Vitrectomy for ERM or VMT usually leads to improvement of the metamorphopsia and visual acuity. On average, approximately 80% of patients with ERM or VMT will improve by at least 2 lines of visual acuity following vitrectomy surgery. Epiretinal membranes (ERMs) are sheet-like structures that develop on the inner surface of the neurosensory retina. Vitreomacular adhesion (VMA) is an attachment of the posterior cortical vitreous to the macula without resultant traction. Vitreomacular traction (VMT) occurs when the posterior cortical vitreous partially separates from the retina yet some areas of adhesion remain that exert tractional forces on the neurosensory retina. Thickening, distortion, intraretinal cystoid changes, macular hole, and even subretinal fluid in the macula can result from the VMT.6Johnson MW Perifoveal vitreous detachment and its macular complications.Trans Am Ophthalmol Soc. 2005; 103: 537-567PubMed Google Scholar The macular changes that result from either ERM or VMT lead to similar symptoms: reduced visual acuity, metamorphopsia, difficulty using both eyes together, and even diplopia. The patient population is predominately adults. ♦Describe the pathogenesis of ERM and VMT♦Recognize symptoms and signs of ERM and VMT♦Describe the natural history without treatment♦Propose a treatment strategy♦Educate the patient about treatment options♦Optimize visual function and/or relief of symptoms Epiretinal membranes consist of fibrocellular proliferation on the surface of the neurosensory retina, with or without wrinkling of the retina. They comprise reactive cellular elements, vitreous structures, and fibrotic components.1Steel DH Lotery AJ Idiopathic vitreomacular traction and macular hole: a comprehensive review of pathophysiology, diagnosis, and treatment.Eye (Lond). 2013; 27: S1-21Crossref PubMed Scopus (132) Google Scholar Idiopathic ERMs do not have a clearly identifiable cause.4Bu SC Kuijer R Li XR Hooymans JM Los LI Idiopathic epiretinal membrane.Retina. 2014; 34: 2317-2335Crossref PubMed Scopus (125) Google Scholar Secondary ERMs may occur after retinal breaks or detachments, or following intraocular surgery, trauma, or retinal laser or cryotherapy treatment.1Steel DH Lotery AJ Idiopathic vitreomacular traction and macular hole: a comprehensive review of pathophysiology, diagnosis, and treatment.Eye (Lond). 2013; 27: S1-21Crossref PubMed Scopus (132) Google Scholar An ERM is likely due to reactive wound healing and is associated with a proliferation of either reactive retinal pigment epithelial (RPE) cells and/or retinal glial cells. Epiretinal membranes are also common in eyes with retinal vascular disease5Cheung N Tan SP Lee SY et al.Prevalence and risk factors for epiretinal membrane: the Singapore Epidemiology of Eye Disease study.Br J Ophthalmol. 2017; 101: 371-376PubMed Google Scholar, 7Duan XR Liang YB Friedman DS et al.Prevalence and associations of epiretinal membranes in a rural Chinese adult population: the Handan Eye Study.Invest Ophthalmol Vis Sci. 2009; 50: 2018-2023Crossref PubMed Scopus (68) Google Scholar (e.g., diabetic retinopathy and venous occlusions) and/or inflammation. A systematic review from 2016 which included over 49,000 subjects found that ERMs are relatively common among aged population the meta-analysis showed that only greater age and female gender significantly conferred a higher risk of ERM.8Xiao W Chen X Yan W Zhu Z He M Prevalence and risk factors of epiretinal membranes: a systematic review and meta-analysis of population-based studies.BMJ Open. 2017; 7e014644Crossref PubMed Scopus (26) Google Scholar The vitreous is most firmly attached at the vitreous base, the optic nerve head, and the macula.9Sebag J Anatomy and pathology of the vitreo-retinal interface.Eye (Lond). 1992; 6: 541-552Crossref PubMed Scopus (152) Google Scholar, 10Sebag J Anomalous posterior vitreous detachment: a unifying concept in vitreo-retinal disease.Graefes Arch Clin Exp Ophthalmol. 2004; 242: 690-698Crossref PubMed Scopus (334) Google Scholar A posterior vitreous detachment (PVD) evolves and progresses over years.6Johnson MW Perifoveal vitreous detachment and its macular complications.Trans Am Ophthalmol Soc. 2005; 103: 537-567PubMed Google Scholar Initially, the posterior vitreous will partially detach yet will remain attached within the macular region. Eventually, a complete detachment occurs when the vitreous detaches from the macula and finally from the optic nerve head. When the vitreous detaches from the nerve head, the patient may see the acute onset of floaters or even flashes or photopsia. Combined, these represent the classic symptoms for the onset of an acute PVD. On fundus examination, a Weiss ring represents the glial remnant from the attachment at the optic nerve on the posterior cortical vitreous and is typically seen on the posterior vitreous face anterior to the optic nerve. During the evolution of a PVD, vitreous may remain adherent to the macula. Vitreomacular adhesion, the attachment of the posterior cortical vitreous to the neurosensory retina, may represent the normal evolution of a PVD. Vitreomacular traction occurs when the perimacular vitreous continues to separate from the posterior retina yet remains adherent to a region or area near the center of the macula.6Johnson MW Perifoveal vitreous detachment and its macular complications.Trans Am Ophthalmol Soc. 2005; 103: 537-567PubMed Google Scholar, 10Sebag J Anomalous posterior vitreous detachment: a unifying concept in vitreo-retinal disease.Graefes Arch Clin Exp Ophthalmol. 2004; 242: 690-698Crossref PubMed Scopus (334) Google Scholar The pathologic mechanism responsible for such an abnormal adhesion within the macula that leads to VMT is unclear. The combination of attachment at the macula with surrounding vitreous separation creates traction and may lead to thickening, distortion, intraretinal cystoid changes and even subretinal fluid or tractional detachment at the macula.6Johnson MW Perifoveal vitreous detachment and its macular complications.Trans Am Ophthalmol Soc. 2005; 103: 537-567PubMed Google Scholar Epiretinal membranes can also lead to macular traction and similar visual symptoms. Both ERM and VMT may lead to loss in visual acuity, metamorphopsia, difficulty in using both eyes together, even diplopia. The most common type of ERM appears as a thin, translucent, cellophane-like membrane on the surface of the retina.9Sebag J Anatomy and pathology of the vitreo-retinal interface.Eye (Lond). 1992; 6: 541-552Crossref PubMed Scopus (152) Google Scholar, 11Wise GN Clinical features of idiopathic preretinal macular fibrosis. Schoenberg Lecture.Am J Ophthalmol. 1975; 79: 347-349Google Scholar An ERM may not lead to tractional changes, and the underlying neurosensory retina may often appear normal. Epiretinal membranes can contract, however, leading to folds in the retina, distortion of the inner and even the outer macula, traction on retinal vessels, and even displacement of the macula, or ectopia. The normal foveal depression is often absent or distorted, and the macula may develop cystoid spaces, lamellar macular hole, or even a full-thickness hole. Epiretinal membranes that have a thicker, white, fibrotic appearance that obscures the underlying retina, are more likely to become symptomatic and displace the macula than the thinner, more translucent ERMS.4Bu SC Kuijer R Li XR Hooymans JM Los LI Idiopathic epiretinal membrane.Retina. 2014; 34: 2317-2335Crossref PubMed Scopus (125) Google Scholar, 12Fraser-Bell S Guzowski M Rochtchina E Wang JJ Mitchell P Five-year cumulative incidence and progression of epiretinal membranes: the Blue Mountains Eye Study.Ophthalmology. 2003; 110: 34-40Abstract Full Text Full Text PDF PubMed Scopus (183) Google Scholar The macular changes in VMT are often similar to the changes of the retina that result from an ERM. In VMT, raised edges of adherent vitreous may be seen in a peripapillary distribution around the optic nerve head and is referred to as vitreopapillary traction. This condition can be confused with optic nerve disorders such as papilledema.13Kim YW Jeoung JW Yu HG Vitreopapillary traction in eyes with idiopathic epiretinal membrane: a spectral-domain optical coherence tomography study.Ophthalmology. 2014; 121: 1976-1982Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar There is some suspicion that vitreopapillary traction might be associated with decreased vision and even ischemic optic neuropathy in some cases.14Parsa CF Hoyt WF Nonarteritic anterior ischemic optic neuropathy (NAION): a misnomer. Rearranging pieces of a puzzle to reveal a nonischemic papillopathy caused by vitreous separation.Ophthalmology. 2015; 122: 439-442Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar Further studies are required to verify this. Epiretinal membrane and VMT are relatively common retinal conditions. Higher prevalence of both conditions is associated with older age.4Bu SC Kuijer R Li XR Hooymans JM Los LI Idiopathic epiretinal membrane.Retina. 2014; 34: 2317-2335Crossref PubMed Scopus (125) Google Scholar Vitreomacular traction is less common than ERM and affects an estimated 0.4% to 2.0% in a population of U.S. adults over the age of 63.15Meuer SM Myers CE Klein BE et al.The epidemiology of vitreoretinal interface abnormalities as detected by spectral-domain optical coherence tomography: The Beaver Dam Eye Study.Ophthalmology. 2015; 122: 787-795Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar The prevalence of ERMs is based on several population-based studies conducted in various ethnic groups worldwide over the past 20 years. It is estimated to occur in approximately 30 million adults in the United States 43 to 86 years old.16Klein R Klein BE Wang Q Moss SE The epidemiology of epiretinal membranes.Trans Am Ophthalmol Soc. 1994; 92 (discussion 425-430.): 403-425PubMed Google Scholar Epiretinal membranes may be bilateral in up to 20% to 35% of cases.7Duan XR Liang YB Friedman DS et al.Prevalence and associations of epiretinal membranes in a rural Chinese adult population: the Handan Eye Study.Invest Ophthalmol Vis Sci. 2009; 50: 2018-2023Crossref PubMed Scopus (68) Google Scholar, 17Mitchell P Smith W Chey T Wang JJ Chang A Prevalence and associations of epiretinal membranes. The Blue Mountains Eye Study, Australia.Ophthalmology. 1997; 104: 1033-1040Abstract Full Text PDF PubMed Scopus (291) Google Scholar, 18McCarty DJ Mukesh BN Chikani V et al.Prevalence and associations of epiretinal membranes in the visual impairment project.Am J Ophthalmol. 2005; 140: 288-294Abstract Full Text Full Text PDF PubMed Scopus (130) Google Scholar, 19Ng CH Cheung N Wang JJ et al.Prevalence and risk factors for epiretinal membranes in a multi-ethnic United States population.Ophthalmology. 2011; 118: 694-699Abstract Full Text Full Text PDF PubMed Scopus (124) Google Scholar Prevalence rates4Bu SC Kuijer R Li XR Hooymans JM Los LI Idiopathic epiretinal membrane.Retina. 2014; 34: 2317-2335Crossref PubMed Scopus (125) Google Scholar range from a low of 2.2% and 3.4% in the Beijing Eye Study20You Q Xu L Jonas JB Prevalence and associations of epiretinal membranes in adult Chinese: the Beijing eye study.Eye (Lond). 2008; 22: 874-879Crossref PubMed Scopus (76) Google Scholar and in the Handan Eye Study in rural China, respectively,7Duan XR Liang YB Friedman DS et al.Prevalence and associations of epiretinal membranes in a rural Chinese adult population: the Handan Eye Study.Invest Ophthalmol Vis Sci. 2009; 50: 2018-2023Crossref PubMed Scopus (68) Google Scholar to moderate (7% and 8.9%) in two Australian populations,17Mitchell P Smith W Chey T Wang JJ Chang A Prevalence and associations of epiretinal membranes. The Blue Mountains Eye Study, Australia.Ophthalmology. 1997; 104: 1033-1040Abstract Full Text PDF PubMed Scopus (291) Google Scholar, 21Aung KZ Makeyeva G Adams MK et al.The prevalence and risk factors of epiretinal membranes: the Melbourne Collaborative Cohort Study.Retina. 2013; 33: 1026-1