title: [Comparison of objective assessment using the sweep pattern visual evoked response acuity (SPVERA) and illiterate E visual acuity].
abstract: OBJECTIVE
  To compare the vision objectively assessed by SPVERA with the illiterate E Acuity in normal subjects.
  
  
  METHODS
  The effect of artificially induced image defocusing on visual acuities (Vas) measured by SPVEP and illiterate E chart measurement was studied in 14 normal subjects. SPVEP was recorded using vertical gratings of 8 different spatial frequencies ranging from 0.235 9 to 30.203 2 c/deg. The responses were averaged and displayed through the discrete Fourier transform on the monitor display. SPVERA was determined by extrapolating the PVER amplitude -spatial frequency function to baseline. SPVERA was compared with illiterate E visual acuity measured under the same conditions of optical defocus.
  
  
  RESULTS
  With moderate defocusing (<+1.0 diopter (D),VA > 0.42), the SPVERA were equal to or poorer than the illiterate E visual acuity. With more defocus (> +2.0 diopter (D), VA < 0.3),the SPVERA became better than the illiterate E chart Visual Acuity. The correlation between the two acuities was r2 = 0.919.
  
  
  CONCLUSIONS
  SPVERA and the illiterate E visual acuity correlated to a certain degree. We conclude that the SPVERA is effective in estimating vision objectively.
authors.affiliation: Institute of Forensic Science, Ministry of Justice, P. R. China, Shanghai 200063, China.
authors.forename: Rui-Jue
authors.initials: RJ
authors.lastname: Liu
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Liu
mesh_terms: D000328:Adult; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation; D014786:Vision Disorders / Q000503:physiopathology*; D014787:Vision Tests / Q000379:methods*; D014792:Visual Acuity / Q000502:physiology*