DEC 07, 2009
Researchers sought to determine the probability of measuring quantitative (logMAR) visual acuity in children with cerebral palsy (CP). Subjects in the study were 76 children with CP, varying levels of gross motor function and a mean age of 5.9 years. The researchers were able to measure logMAR acuity in 88 percent of subjects using either optotypes or spatial-sweep visually evoked potentials (SSVEP). The success rate decreased with increasing severity on the five-point Gross Motor Function Classification Scale (GMFCS), although logMAR acuities were obtained in 56 percent of children with the most severe GMFCS level.
Results were similar when CP severity was classified using physiological-anatomical subtype, with logMAR acuities obtained in 98 percent of subjects with hemiplegic or diplegic CP and 76 percent with quadriplegic CP. Mean logMAR acuity was around 2 Snellen-equivalent lines worse in the children with CP compared with age-matched controls without CP (20/48 vs. 20/33). Visual acuity was immeasurable and paired with flash visually evoked potentials (FVEP) evidence of substantial sensory visual pathway damage in only eight percent of the study's subjects with CP.