title: Visual function in Vogt-Koyanagi-Harada patients.
abstract: BACKGROUND
  Vogt-Koyanagi-Harada (VKH) disease presents with anterior segment inflammation, choroiditis and exudative retinal detachment. Following resolution of the inflammation, VKH patients have been noted to complain of visual disturbances despite good visual acuity. We therefore investigated the visual function deficits of convalescent VKH patients.
  
  
  METHODS
  A cross-sectional observational nonrandomized controlled study of convalescent VKH patients from the Uveitis Service of the Singapore National Eye Centre, and normal subjects was performed. The best-corrected visual acuities (BCVA) and multifocal electroretinograms (mfERGs) of VKH patients with and without peripapillary atrophy (PPA) were compared with those of the normal eyes. The mfERG results were subdivided into those obtained from the peripapillary area and those from the rest of the macular.
  
  
  RESULTS
  Eleven VKH eyes with large PPA to disc ratios (PPA/D ratio >2), 15 VKH eyes with PPA/D ratios<1 and 6 normal eyes were included in the study. Five eyes (54.5%) of VKH patients with PPA/D>2 had a BCVA of less than 20/40. All the other eyes had 20/20 vision. Nine of the 11 VKH eyes with PPA/D>2 also had large areas of chorioretinal atrophy. The mfERG responses of VKH eyes with PPA/D ratio >2 were markedly reduced in amplitude (p<0.001) and delayed in implicit time (p<0.001) throughout the entire macular area. VKH patients with PPA/D ratio<1 had significantly reduced mfERG amplitudes throughout the entire macular area, as well as delayed implicit times at the peripapillary region (p=0.026). Sub-division of VKH eyes with PPA/D<1 into eyes with no PPA and eyes with a small PPA, showed that both groups had a similar reduction in response amplitude over the entire macular region. However, the implicit time was significantly delayed in eyes with small PPA when compared to those without PPA (p<0.03).
  
  
  CONCLUSIONS
  VKH patients with large PPA have clinically significant visual dysfunction. VKH patients without PPA also have subclinical retinal dysfunction. The mfERG may be a useful adjunct in the management of VKH by detecting early retinal damage.
authors.affiliation: Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, Singapore. sneccsp@pacific.net.sg
authors.forename: Soon-Phaik
authors.initials: SP
authors.lastname: Chee
authors.forename: Chi D
authors.initials: CD
authors.lastname: Luu
authors.forename: Ching-Li
authors.initials: CL
authors.lastname: Cheng
authors.forename: Wee-Kiak
authors.initials: WK
authors.lastname: Lim
authors.forename: Aliza
authors.initials: A
authors.lastname: Jap
mesh_terms: D003430:Cross-Sectional Studies; D004596:Electroretinography; D006801:Humans; D009896:Optic Atrophy / Q000503:physiopathology; D012160:Retina / Q000503:physiopathology*; D014607:Uveomeningoencephalitic Syndrome / Q000503:physiopathology*; D014786:Vision Disorders / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology*