title: Visual impairment in children with spastic cerebral palsy measured by psychophysical and electrophysiological grating acuity tests.
abstract: BACKGROUND
  This study measured grating visual acuity in 173 children between 6-48 months of age who had different types of spastic cerebral palsy (CP).
  
  
  METHODS
  Behavioural acuity was measured with the Teller Acuity Cards (TAC) using a staircase psychophysical procedure. Electrophysiological visual acuity was estimated using the sweep VEP (sVEP).
  
  
  RESULTS
  The percentage of children outside the superior tolerance limits was 44 of 63 (69%) and 50 of 55 (91%) of tetraplegic, 36 of 56 (64%) and 42 of 53 (79%) of diplegic, 10 of 48 (21%) and 12 of 40 (30%) of hemiplegic for sVEP and TAC, respectively. For the sVEP, the greater visual acuity deficit found in the tetraplegic group was significantly different from that of the hemiplegic group (p<0.001). In the TAC procedure the mean visual acuity deficits of the tetraplegic and diplegic groups were significantly different from that of hemiplegic group (p<0.001). The differences between sVEP and TAC means of visual acuity difference were statistically significant for the tetraplegic (p<0.001), diplegic (p<0.001), and hemiplegic group (p=0.004).
  
  
  CONCLUSIONS
  Better visual acuities were obtained in both procedures for hemiplegic children compared to diplegic or tetraplegic. Tetraplegic and diplegic children showed greater discrepancies between the TAC and sVEP results. Inter-ocular acuity difference was more frequent in sVEP measurements.
  
  
  CONCLUSIONS
  Electrophysiologically measured visual acuity is better than behavioural visual acuity in children with CP.
authors.affiliation: Department Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, São Paulo, Brazil. costamf@usp.br
authors.forename: Marcelo Fernandes
authors.initials: MF
authors.lastname: Costa
authors.forename: Dora Fix
authors.initials: DF
authors.lastname: Ventura
mesh_terms: D002547:Cerebral Palsy / Q000150:complications / Q000503:physiopathology*; D002675:Child, Preschool; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D014786:Vision Disorders / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D014787:Vision Tests; D014792:Visual Acuity / Q000502:physiology*