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Development of visual acuity in preschool children as measured with Landolt C and Tumbling E charts
Yu-Hung Lai1, Hwei-Zu Wang, Hsin-Tien Hsu
1Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
Insights
Visual acuity in preschool children improves with age, with the Tumbling E chart yielding higher scores than the Landolt C chart in younger children. Age- and test-specific thresholds are crucial for accurate assessment.
Area of Science:
- Ophthalmology
- Pediatric Optometry
- Vision Science
Background:
- Accurate visual acuity assessment in preschool children is vital for early detection of vision impairments.
- Standardized charts like Landolt C and Tumbling E are used, but their performance in young children may differ.
- Understanding age-specific visual development is crucial for establishing appropriate screening criteria.
Purpose of the Study:
- To compare visual acuity development using Landolt C and Tumbling E charts in preschool children aged 3-6 years.
- To determine if age-specific and test-specific visual acuity thresholds are necessary for this age group.
Main Methods:
- Retrospective analysis of visual acuity data from 821 children (Tumbling E chart) and 212 children (Landolt C chart) aged 3-6 years.
- Inclusion criteria: healthy children with specific refractive error limits (hyperopia <4.5 D, myopia <3.0 D, astigmatism <2.0 D, anisometropia <2.0 D).
- Comparison of best-corrected visual acuity (BCVA) between the two chart groups and across age bands (3-4 years vs. 5-6 years).
Main Results:
- Mean BCVA improved significantly with age in both groups (P < 0.001).
- Children assessed with the C chart had significantly greater astigmatism than those with the E chart (P < 0.001).
- The E chart yielded significantly better BCVA than the C chart in 3-4 year olds (P < 0.001), but this difference diminished in 5-6 year olds.
Conclusions:
- Visual acuity measurements using C and E charts converge towards adult values in children aged 5-6 years.
- The Tumbling E chart provides a higher visual acuity score compared to the Landolt C chart in younger preschool children (3-4 years).
- Normal visual acuity thresholds for preschool children (3-6 years) must be specific to both the child's age and the testing chart used.
Purpose:
To investigate the visual acuity development as measured by Landolt C and Tumbling E charts ("C chart" and "E chart") in preschool children.
Methods:
Visual acuity measurements of healthy children ages 3-6 years who had been evaluated with the use of E charts (during kindergarten screening) and C charts (in a hospital setting) from 2005 to 2007 were studied. Inclusion criteria were hyperopia <4.5 D, myopia <3.0 D, astigmatism <2.0 D, and anisometropia <2.0 D. The best-corrected visual acuity (BCVA) in each group was analyzed.
Results:
There were 821 children in the E chart group and 212 in the C chart group (mean age, 5 years). The mean BCVA improved from between age 3-4 years and age 5-6 years in both groups (P < 0.001). Children in the C chart group had significantly greater astigmatism compared with those in the E chart group (0.66 D ± 0.47 vs 0.28 D ± 0.39; P < 0.001). The BCVA obtained by E chart was greater than that obtained by C chart at age 3-4 years (logMAR 0.0246 ± 0.0646 vs 0.1158 ± 0.1462, P < 0.001), but not at age 5-6 years.
Conclusions:
When children reach 5-6 years of age, visual acuity values obtained by C and E charts approach those observed in adults. In younger patients, the E chart obtains a greater visual acuity score than the C chart. Thus, thresholds for normal visual acuity in preschool children ages 3-6 years should be both age specific and test specific.
