Purpose:
To describe the clinical characteristics, optical coherence tomography (OCT), and surgical outcomes with histopathology of epiretinal membranes (ERMs) in patients with foveal herniation.
Methods:
An interventional, retrospective case series of six eyes in six patients with ERMs and foveal herniation. Data collected included demographics, ophthalmic examination, OCT findings, and histopathology. Preoperative visual acuity (Vac) and OCT foveal thicknesses were compared to postoperative values.
Results:
Clinically, ERMs with foveal herniation were most opaque surrounding the central area of foveal herniation that markedly accentuated the xanthophilic pigment centrally. Five of six patients had a coexisting peripheral retinal break (1hole, 4 tears). OCT imaged concentric folds of the inner retinal layers without a retinal detachment. Mean diameter of foveal prolapse was 832 ±251um. Mean logMAR Vac [Snellen equivalent] improved from 1.78 ±0.87 [20/1200] to 0.57 ±0.30 [20/ 72]; (p= 0.018). Mean highest foveal thickness decreased from 974±288um to 538±264um; (p= 0.017) after ERM removal. Histopathology revealed fibrocellular membranes that stained positively for smooth muscle actin and retinal pigment epithelial (RPE) marker (CAM 5.2), consistent with metaplastic RPE cells in all cases with glial elements noted in 2 specimens.
Conclusions:
ERMs with foveal herniation result from circumferential contraction and folding of the inner retina with prolapse of the foveola centrally, without the presence of a retinal detachment. Risk factors may include peripheral retinal breaks and liberated RPE cells that appear to contribute to ERM formation and contraction. Surgical removal of these membranes can result in improvement in visual acuity and retinal thickness.
Keywords: macula/fovea • vitreoretinal surgery • imaging/image analysis: clinical