title: Detection of early visual impairment in patients with epiretinal membrane.
abstract: OBJECTIVE
  Patients with epiretinal membrane sometimes complain of impaired central visual function, despite good best corrected visual acuity (BCVA), as measured by visual acuity (VA) charts. Here, we evaluate early epiretinal membrane-induced changes in central VA.
  
  
  METHODS
  Subjects were 72 eyes of 36 patients with epiretinal membrane in only one eye and a BCVA in each eye better than 1.0, as measured by conventional Landolt C chart, at the Retina Division Clinic of the Department of Ophthalmology, Keio University Hospital, between December 2010 and November 2011. The conventional Landolt VA, functional VA (FVA) and contrast VA measurements were taken after a general eye examination. For the FVA, Landolt optotypes were sequentially displayed every 2 seconds, which size was changed according to the correctness of the answer. To exclude the influence of other diseases, a standard Schirmer test was performed to diagnose dry eye, and corneal and lens densities were evaluated.
  
  
  RESULTS
  Average BCVA measured by Landolt C chart was not changed between affected and unaffected fellow eyes. However, the affected eyes showed a poorer FVA score (0.21 ± 0.12, affected; 0.09 ± 0.12, fellow) and visual maintenance ratio (VMR) (0.90 ± 0.04, affected; 0.94 ± 0.04, fellow), measured by the FVA system, and contrast VA score (0.35 ± 0.11, affected; 0.25 ± 0.14, fellow) than fellow eyes. The FVA and contrast VA values were correlated with the presence of epiretinal membrane, but not with the presence of dry eye, cataract and corneal densities.
  
  
  CONCLUSIONS
  FVA and contrast VA results reflected early changes in central visual function caused by epiretinal membrane, which were not detected by conventional Landolt BCVA.
authors: Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.
authors: Yasuyo
authors: Y
authors: Nishi
authors: Hajime
authors: H
authors: Shinoda
authors: Atsuro
authors: A
authors: Uchida
authors: Takashi
authors: T
authors: Koto
authors: Hiroshi
authors: H
authors: Mochimaru
authors: Norihiro
authors: N
authors: Nagai
authors: Kazuo
authors: K
authors: Tsubota
authors: Yoko
authors: Y
authors: Ozawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015350:Contrast Sensitivity; D042241:Early Diagnosis; D019773:Epiretinal Membrane / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009887:Ophthalmoscopy / Q000379:methods; D012189:Retrospective Studies; D014786:Vision Disorders / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D014787:Vision Tests / Q000379:methods*; D014792:Visual Acuity
keywords: contrast visual acuity; epiretinal membrane; functional visual acuity; visual function measurement