Epiretinal Membrane – June 2016

June 2016

Case Presentation

A 68 year old man complained of gradual blurry vision with metamorphosia in his right eye over the past 1-2 years. He reports the distortion centrally to be getting worse with time. He has had cataract surgery in both eyes.

Examination

Visual acuity with myopic correction was 20/60 in the right eye and 20/30 in the left. The anterior segment was within normal limits with well-centered posterior capsular intraocular lenses. The posterior segment exam revealed diffuse epiretinal membrane (ERM) in the right eye.

Diagnostic Testing

Fundus photographs revealed the presence an ERM and optical coherence tomography confirmed the finding and elucidated its morphology. (Figure 1).

Figure1
Figure 1

Clinical Course

The patient elected to pursue pars plana vitrectomy with internal limiting membrane (ILM) and ERM peel. The membrane was removed without complication.
The following series of pictures reveal the process of removing a macular pucker.

Figure 2: Staining the ILM (and negatively stain the ERM) with a green dye.
Figure 3: Initiate membrane peel with looped instrument.
Figure 4: Engagement of ERM with forceps.
Figure 5: Majority of ERM grasped with forceps.
Figure 6: Underlying ILM grasped with forceps.
Figure 7: Post peel with typical intraretinal heme (which resolve without consequence).

Figure2
Figure 2
Figure3
Figure 3
Figure4
Figure 4

 

Figure5
Figure 5
Figure6
Figure 6
Figure7
Figure 7

 

The patient’s visual acuity has been improving slowly after surgery as might be expected. Six months after the surgery he has 20/40 visual acuity and reports much improved central distortion in his right eye (Figure 8).

Figure1
Figure 1 (Before)
Figure8
Figure 8 (After)

Discussion

When glial cells from the neurosensory retina proliferate and migrate to the surgace of the ILM they settle to form a semi-translucent fibrocellular sheath. This new glial scar tissue is commonly referred to as Cellophane Maculopathy, Macular Pucker, or Epiretinal Membrane (ERM).

Most ERM’s are idiopathic, and occur as a result of aging. This event occurs within the vitreoretinal junction where the posterior hyaloid membrane and the ILM meet. It is widely accepted that idiopathic ERM’s occur after these two entities separate, or detach from one another. The posterior vitreous detachment (PVD) may leave breaks within the ILM which allows for the migration and settlement of neurosensory support cells. This glial fibrocellular sheath is contractile in nature, and may cause distortion of all layers of the neurosensory retina. Macular contraction is also responsible for irregularities on the surface of the inner retina. As a result of this event patients will notice decreased visual acuity (VA), and metamorphosia (distortion).

Empiretinal membrane is a very common cause of distorted or blurry vision in patients above 50 years old. In this particular case, the patient had an uncomplicated cataract extraction and his residual blurry vision was thought secondary to epiretinal membrane. In this situation, one must decide between observation and surgery. If operating, what is the optimal visual acuity when surgical correction makes the most sense?

As with any ocular surgery, there are multiple factors including the patient’s age, ocular and systemic comorbidities, as well as his or her subjective visual symptoms that must be taken into account when deciding if or when to operate.

Optical Coherence tomography allows for direct visualization of the epiretinal membrane. One can ascertain qualities such as the area of the retina affected, thickness of the membrane, as well as the level of distortion of the underlying retina.

The procedure has progressed over the years, and now with small guage and new instrumentation, is often being considered sooner in the course of disease.

The majority of patients who undergo pars plana vitrectomy with ILM peel for epiretinal membrane have excellent visual outcomes.

References

Macular Pucker: To peel or not to peel the internal limiting membrane? A Microperimetric Response Ripandelli G, Carinci, F, Piaggi P, Guidi G, Pileri M, Cupo G, Sartini MS, Parisi V, Baldanzellu S, Giusti C, Nardi M, Stirpe M, Lazzeri S. Retinal. 2015 Mar;35(3)498-507

Preoperative and intraoperative prognostic factors of epiretinal membranes using chromovitrectomy and internal limiting membrane peeling Machado LM, Furlani BA, Navarro RM, Farah ME, Maia A, Magalhaes O Jr, Rodrigues EB, Moraes N, Maia M. Opthalmic Surg Lasers Imaging Retina. 2015 Apr;46(4):457-62

Foveal contour changes following surgery for idiopathic epiretinal membrane. Matthews NR, Tarima S, Kim DG, Kim JE. Invest Ophthalmol Vis Sci.2014 Nov 13;55(12):7754-60

Outer Retinal Morphological Changes and Visual Function after Removal of Epiretinal Membrane Rii T, Itoh Y, Inoue M, Hirota K, Hirakata A. Can J Ophthalmol. 2014 Oct;49(5):436-42