title: EPIRETINAL MEMBRANE IN NONEXUDATIVE AGE-RELATED MACULAR DEGENERATION: Anatomical Features, Visual Outcomes and Prognostic Factors.
abstract: OBJECTIVE
  To evaluate clinical characteristics, assess surgical outcomes, and determine prognostic factors after vitrectomy for epiretinal membrane (ERM) associated with nonexudative age-related macular degeneration (AMD).
  
  
  METHODS
  This study comprised 171 consecutive patients with idiopathic ERM (n = 132) or nonexudative AMD-associated ERM (AMD-ERM, n = 39) undergoing vitrectomy. Preoperative morphologic characteristics on spectral-domain optical coherence tomography images and postoperative outcomes of the two groups were compared. Factors influencing postoperative best-corrected visual acuity in the AMD-ERM group were also analyzed.
  
  
  RESULTS
  The AMD-ERM group was more likely to have an ERM with a smooth appearance (P = 0.009), a less severe vessel traction score (P = 0.002), a thinner central foveal thickness (P = 0.016), and more photoreceptor disruption than idiopathic ERM group. Mean central foveal thickness improved from 404.92 ± 82.08 and 369.87 ± 68.17 μm at baseline to 339.77 ± 39.27 and 331.72 ± 45.76 μm 1 year after surgery in eyes with idiopathic ERM and AMD-ERM, respectively (all P < 0.001). Mean logarithm of the minimum angle of resolution best-corrected visual acuity improved from 0.30 (20/40) ± 0.21 and 0.32 (20/42) ± 0.18 at baseline to 0.02 (20/21) ± 0.09 and 0.13 (20/27) ± 0.17 1 year after surgery in the idiopathic ERM and AMD-ERM groups, respectively (all P < 0.001). Baseline integrity of the ellipsoid zone line (P = 0.009) and preoperative best-corrected visual acuity (P = 0.024) were significantly correlated with visual outcome in the AMD-ERM group.
  
  
  CONCLUSIONS
  Morphologic differences between AMD-ERM and idiopathic ERM were identified. Vitrectomy resulted in significant anatomical and visual improvements in eyes with AMD-ERM, but final visual outcome was worse in these eyes than in those with idiopathic ERM.
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Eun Kyoung
authors.initials: EK
authors.lastname: Lee
authors.forename: Sang-Yoon
authors.initials: SY
authors.lastname: Lee
authors.forename: Hyeong Gon
authors.initials: HG
authors.lastname: Yu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019773:Epiretinal Membrane / Q000503:physiopathology / Q000601:surgery*; D005122:Exudates and Transudates; D005260:Female; D057092:Geographic Atrophy / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007431:Intraoperative Complications; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011379:Prognosis; D015593:Retinal Drusen / Q000175:diagnosis; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology*; D014821:Vitrectomy