title: Influence of epiretinal membrane on the measurement of peripapillary retinal nerve fibre layer thickness using spectral-domain coherence tomography.
abstract: OBJECTIVE
  To investigate the effect of epiretinal membrane (ERM) on peripapillary retinal nerve fibre layer (RNFL) thickness measurements using spectral-domain optical coherence tomography (Spectralis; Heidelberg Engineering).
  
  
  METHODS
  A total of 134 patients with idiopathic ERM and 63 healthy controls were included in this observational comparative study. We categorised ERMs into three severity grades, based on retinal appearance in macular scans. All eyes with ERM were classified into two groups; those involving the peripapillary scan area (ERM+pp, n=68 eyes) and not involving the peripapillary scan area (ERM-pp, n=66 eyes) using the macular disc scan. Peripapillary RNFL thickness was compared between related subgroups as (ERM+pp) or (ERM-pp) group.
  
  
  RESULTS
  Temporal peripapillary RNFL thickness was significantly greater in the ERM+pp group (109.44±22.91 μm), followed by the ERM-pp (82.60±11.77 μm, p<0.001) and control (75.42±10.49 μm, p<0.001) groups. Temporal peripapillary RNFL thickness significantly increased with ERM grade in the ERM+pp and ERM-pp groups (both p<0.001). The peripapillary RNFL thickness was overestimated (exceeded 99th percentile) in the temporal sector in 49 eyes (72.1%) in the ERM+pp group and in 5 eyes (7.6%) in the ERM-pp group.
  
  
  CONCLUSIONS
  Temporal and global peripapillary RNFL thickness is significantly higher in eyes with ERM, especially when the ERM extends into the peripapillary area. However, some eyes with an ERM that does not involve the peripapillary scan area still show peripapillary RNFL thickening. Measured peripapillary RNFL thickness was significantly and positively correlated with ERM severity.
authors.affiliation: Tae Ophthalmic Clinic, Anyang, Korea.
authors.forename: Yun Ha
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyoung Won
authors.initials: HW
authors.lastname: Bae
authors.affiliation: Department of Ophthalmology, Maryknoll Medical Center, Busan, Korea.
authors.forename: Sang Jin
authors.initials: SJ
authors.lastname: Seo
authors.affiliation: Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sang Yeop
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seok Ho
authors.initials: SH
authors.lastname: Beon
authors.affiliation: Department of Ophthalmology, Eyereum Ophthalmic Clinic, Seoul, Korea.
authors.forename: Sungyong
authors.initials: S
authors.lastname: Kang
authors.affiliation: Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Chan Yun
authors.initials: CY
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D019773:Epiretinal Membrane / Q000175:diagnosis*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity
keywords: Diagnostic tests/Investigation