Spontaneous epiretinal membrane separation.

Introduction

Idiopathic epiretinal membranes (ERM) occur mainly in patients above 50 years of age, and are bilateral in up to 20% of cases.[1] ERM undergoes spontaneous separation most commonly in young subjects, women, and myopes; it occurs in approximately 1–3% of cases overall, and generally results in visual improvement.[2-5] Several retinal diseases and mechanisms resulting in spontaneous ERM separation have been described.[6] It has been noted to occur in patients with Toxoplasmic retinochoroiditis, Stargardt macular dystrophy, and Leber’s multiple military aneurysms, and has been associated with trauma and laser treatment.[6-9] Here, we present spectral-domain optical coherence tomography (SD-OCT) images documenting sequential spontaneous ERM separation.

Case Report

A 68-year-old woman presented with 1–2 months of decreasing vision in her right eye. Past ocular history included bilateral radial keratotomy 16 years prior. Visual acuity (VA) was 20/60 in the right eye and 20/30 in the left eye. Anterior segment evaluation and intraocular pressures were normal. Metamorphopsia was present on Amsler grid. Posterior vitreous detachments (PVD) were noted bilaterally. SD-OCT showed an ERM bilaterally [right eye shown in [Figure 1a]. We decided to observe the patient without surgery. Left eye VA and ERM remained stable throughout subsequent examinations. At 4 months, VA in the right eye was unchanged. SD-OCT showed spontaneous ERM separation temporal to the fovea where it remained attached [Figure 1b]. At 7 months, VA was 20/60 in the right eye. SD-OCT showed further separation of the ERM from the fovea [Figure 1c]. At 12 months, best-corrected VA was 20/40 in the right eye. SD-OCT showed a lamellar hole with continued separation of the ERM crossing the fovea and remaining attached nasal to the fovea [Figure 1d].

Figure 1

(a) At presentation. Epiretinal membrane (ERM) is fully attached at and nasal to the fovea, (b) 4 months later. ERM scrolled-up (white star) and separated temporal to the fovea. ERM is still attached at the fovea, (c) 6 months later. ERM scrolled-up edge (white star) continues to separate. It now appears detached from the fovea. ERM created a pseudohole and pulled up the retina temporal to the fovea, (d) 12 months later. ERM has fully separated from the fovea and is now separating nasal to the fovea (white star). Perifoveal cystoid change is present (white arrows)

Comment

Surgical removal of ERM results in visual improvement in 75-85% of eyes.[1011] Conservative treatment of our patient obviated the need for surgery because the ERM spontaneously peeled across the fovea. This process may have been associated with PVD observed in our patient, and supports previous similar observations.[1213] Non-surgical approach has been previously shown in the literature to result in improved vision in select circumstances.[4814] Vision improved from 20/60 to 20/40 in our patient.

While ERM are known to spontaneously peel, this is a rare event and should not influence decision for surgical intervention. Conversely, monitoring spontaneous ERM peel on SD-OCT may defer surgical intervention and indicate observation for further relief of traction on the fovea.