Epiretinal membrane (ERM) is a fairly common finding in people over age 50 years. Many ERMs are discovered incidentally during routine ophthalmologic evaluation. Others become symptomatic and require treatment.
AT A GLANCE
• ILM peeling is generally accepted as a fundamental step in macular hole repair, but its role in surgery for ERM remains controversial.
• Development of eccentric or paracentral macular hole is a relatively unusual complication following ILM peeling.
• It is good practice to initiate ILM peeling far from the fovea.
The mainstay of treatment for symptomatic ERM is surgical removal of the ERM. Vitrectomy techniques have evolved over the years. Modern vitreoretinal techniques most likely involve small-gauge vitrectomy and use of intraocular dyes to stain the ERM and facilitate peeling.
Many authors have advocated peeling of the internal limiting membrane (ILM) to decrease the possibility of ERM recurrence.1-4 Although ILM peeling has generally been accepted as a fundamental step in macular hole repair, its role in surgery for ERM remains controversial. In this article, we present a case that illustrates a relatively uncommon complication of ILM peeling.
Figure 1. Preoperative infrared reflectance (A), blue autofluorescence (B), blue reflectance (C), and infrared autofluorescence (D) images demonstrating the ERM.
CASE REPORT
A 64-year-old woman with no significant past medical or ocular history complained of progressive metamorphopsia in her right eye of 3 months’ duration. On examination, her visual acuity was 20/200 and 20/30 in the right and left eyes, respectively. Her pupils were equally round and reactive to light. There was no afferent pupillary defect. Anterior segment examination was unremarkable.
Funduscopic examination revealed an ERM that distorted the macular anatomy (Figure 1). Spectral-domain optical coherence tomography (SD-OCT) imaging of her right macula confirmed the presence of the ERM (Figure 2).
The patient underwent 25-gauge pars plana vitrectomy with membrane stripping. The posterior hyaloid was identified with triamcinolone and removed. Brilliant blue G vital dye was injected to delineate the ERM. Forceps were used to peel the ERM from the surface of the retina. A second injection of brilliant blue G was performed to identify residual ILM. The residual ILM was peeled without complications.
Figure 2. Preoperative SD-OCT showing the ERM.
One month after her procedure, the patient’s visual acuity was 20/70, and her metamorphopsia was much diminished. On fundus examination, a paracentral full thickness macular hole was noted temporal to the fovea (Figure 3). SD-OCT imaging confirmed the paracentral full thickness macular hole (Figure 4).
Figure 3. Postoperative infrared reflectance showing the absence of the ERM and the presence of a paracentral full thickness macular hole temporal to the fovea.
Because the patient was asymptomatic from this paracentral macular hole and her metamorphopsia had improved, the paracentral macular hole was managed conservatively.
DISCUSSION
Advances in instrumentation and surgical techniques have made removal of an ERM a typical indication for vitreoretinal surgery. Because of its transparent nature, a fine ERM may pose a significant surgical challenge, even to an experienced surgeon. Incomplete removal of the ERM has been identified as a risk factor for ERM recurrence. Several investigators have recommended ILM peeling as a way of reducing the risk of recurrence after ERM removal.5 The use of intraocular dyes such as indocyanine green, trypan blue, and brilliant blue G during vitrectomy has facilitated visualization and peeling of the ILM.6
Even though the ability to stain these tissues has made ILM peeling safer, the procedure is not without complications. Nerve fiber layer damage, retinal edema, retinal hemorrhages, electrophysiologic changes, and visual field changes have all been reported after ILM peeling.7
Figure 4. Postoperative SD-OCT confirming the presence of the paracentral full thickness macular hole.
The case described above illustrates the occurrence of a relatively unusual complication following ILM peeling: development of eccentric or paracentral macular hole. Paracentral macular holes have been reported to occur in 0.6% to 2.6% of macular surgeries with ILM peeling.8-11 They appear to occur at the site where ILM peeling has been initiated or completed.9,11
The pathogenesis of these eccentric or paracentral macular holes remains unclear. It has been suggested that ILM peeling causes Müller cell damage, which in turn causes structural weakening of the retina, leading to macular hole formation.12 According to Mason et al,8 ILM peeling may cause glial apoptosis and reduced retinal function. Others believe that iatrogenic surgical trauma during grasping of the ILM with forceps is responsible for this complication.8,11 Alternatively, it may be that contraction of the remaining edge of the peeled ILM or ERM leads to continued traction and secondary hole formation.8,10
If the paracentral macular hole is relatively far from the fovea, visual prognosis is good.8 Therefore, it is wise to initiate the ILM peel far from the fovea. For the most part, iatrogenic paracentral macular holes do not require additional treatment.9-11
CONCLUSION
Peeling of the ILM in the surgical management of symptomatic ERMs remains controversial. The literature suggests that there is no added benefit in terms of visual outcomes, when eyes that underwent ILM peeling are compared with eyes that did not have the ILM peeled. ILM peeling may reduce the incidence of recurrent ERM. However, many recurrent ERMs are not visually significant.13
1. Carpentier C, Zanolli M, Wu L, et al; Pan-American Collaborative Retina Study Group. Residual internal limiting membrane after epiretinal membrane peeling: results of the Pan-American Collaborative Retina Study Group. Retina. 2013;33(10): 2026-2031.
2. Kwok AK, Lai TY, Li WW, et al. Indocyanine green-assisted internal limiting membrane removal in epiretinal membrane surgery: a clinical and histologic study. Am J Ophthalmol. 2004;138:194-199.
3. Park DW, Dugel PU, Garda J, et al. Macular pucker removal with and without internal limiting membrane peeling: pilot study. Ophthalmology. 2003;110:62-64.
4. Shimada H, Nakashizuka H, Hattori T, et al. Double staining with brilliant blue G and double peeling for epiretinal membranes. Ophthalmology. 2009;116:1370-1376.
5. Schechet SA, DeVience E, Thompson JT. The effect of internal limiting membrane peeling on idiopathic epiretinal membrane surgery, with a review of the literature [published online ahead of print September 9, 2016]. Retina.
6. Hernandez F, Alpizar-Alvarez N, Wu L. Chromovitrectomy: an update. J Ophthalmic Vis Res. 2014;9:251-259.
7. Almony A, Nudleman E, Shah GK, et al. Techniques, rationale, and outcomes of internal limiting membrane peeling. Retina. 2012;32:877-891.
8. Mason JO 3rd, Feist RM, Albert MA Jr. Eccentric macular holes after vitrectomy with peeling of epimacular proliferation. Retina. 2007;27:45-48.
9. Sandali O, El Sanharawi M, Basli E, et al. Paracentral retinal holes occurring after macular surgery: incidence, clinical features, and evolution. Graefes Arch Clin Exp Ophthalmol. 2012;250:1137-1142.
10. Rush RB, Simunovic MP, Aragon AV 2nd, Ysasaga JE. Postoperative macular hole formation after vitrectomy with internal limiting membrane peeling for the treatment of epiretinal membrane. Retina. 2014;34:890-896.
11. Rubinstein A, Bates R, Benjamin L, Shaikh A. Iatrogenic eccentric full thickness macular holes following vitrectomy with ILM peeling for idiopathic macular holes. Eye (Lond). 2005;19:1333-1335.
12. Steven P, Laqua H, Wong D, Hoerauf H. Secondary paracentral retinal holes following internal limiting membrane removal. Br J Ophthalmol. 2006;90:293-295.
13. Roh M, Eliott D. Internal limiting membrane peeling during idiopathic epiretinal membrane removal: literature review. Int Ophthalmol Clin. 2015;55:91-101.
Section Editor Albert Augustin, MD
• professor and chairman of the department of ophthalmology, Staedtisches Klinikum Karlsruhe, in Karlsruhe, Germany
Section Editor Ehab N. El-Rayes, MD, PhD
• professor of ophthalmology, Institute of Ophthalmology in Cairo, Egypt; vitreoretinal consultant, The Retina Clinic, in Cairo, Egypt
Section Editor, Masahito Ohji, MD
• professor and chairman of the department of ophthalmology, Shiga University of Medical Science, in Otsu, Shiga, Japan
Section Editor, Stanislao Rizzo, MD
• chair of the department of ophthalmology, University of Florence, in Florence, Italy
Lihteh Wu, MD
• consulting surgeon, Asociados de Mácula Vítreo y Retina de Costa Rica in San José, Costa Rica
• financial interest: none acknowledged
• +506-2222-1115; LW65@cornell.edu