The range and variability of ophthalmological parameters in normal children aged 4 1/2 to 5 1/2 years

Some standards for childhood ophthalmological variables exist. However, for most parameters, the range of variation found in normal children remains poorly defined.

We have determined the range of normal function for a number of commonly measured ophthalmological variables in 162 children, classified normal by Gold Standard ophthalmological examination. This group is representative of almost 12,000 normal children aged 4 1/2 to 5 1/2 in Nova Scotia.

In 56.8% of eyes the visual acuity was 6/4.5. The use of a chart with crowding bars was more discriminating between differences in higher levels of acuity and highlighted differences in acuity between the two eyes. Randot stereoacuity showed a uniform, non-Gaussian distribution of scores. Cycloplegic refractive errors were distributed about a modal value of between +0.5 and +1.0 diopter. Forty percent of eyes had no detectable astigmatism. Ninety-seven percent of subjects had no heterophoria. Fusional vergence data are presented.

Our results document the complete normal range for selected ophthalmological parameters in normal preschoolers. The values obtained were in general better than expected.