Comparison of preferential looking acuity and pattern reversal visual evoked response acuity in pediatric patients.

BACKGROUND: We compared the visual acuities obtained with preferential looking (PL), the most widely used method of pediatric vision assessment, with those obtained with the spatial frequency sweep pattern-reversal visual evoked response (SPVER). METHODS: Eighty patients (ages 1.5 months to 12 years) with various ocular pathologies participated in this study. The PL acuity was determined using the up-and-down staircase procedure. The PVER was recorded with the spatial frequency sweep method using 10 spatial frequencies; the acuity was determined by placing the best-fit regression line on the descending slope of the PVER amplitude-spatial frequency function toward the higher spatial frequency to the baseline. RESULTS: The PL acuities ranged from 20/25 to < 20/1600 (mean 20/155). The correlation between the two methods was good (r = 0.847). Fifty-six patients (70%) had an acuity agreement within 1.0 octave. When the PL acuity was > 20/128, it was on average better than the PVER acuity. When the PL acuity was lower, the PVER acuity was usually better. This tendency was marked when the visual acuities were very poor (y = 0.552x + 0.362). CONCLUSION: The methods correlate well, although there is a dissociation of acuities in the presence of very low vision. PVER may be a useful addition to PL in assessment of vision in infants and young children.