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Is vision screening in 3-year-old children feasible? Comparison between the Lea Symbol chart and the HVOT (LM) chart
1Division of Ophthalmology, Linköping University Hospital, SE-581 85 Linköping, Sweden.
Insights
Visual screening for children aged 3 years is effective, though testability is lower than at age 4. Both the HVOT and Lea Symbol charts are suitable for visual acuity testing in young children.
Area of Science:
- Ophthalmology
- Pediatric Health
- Vision Screening
Background:
- Early detection of visual impairments is crucial for child development.
- Vision screening at age 3 and 4 years allows for timely intervention.
- Comparing different screening tools and ages is essential for optimizing public health strategies.
Purpose of the Study:
- To compare the effectiveness of visual screening at 3 years versus 4 years of age.
- To evaluate two different visual acuity charts: the HVOT chart and the Lea Symbol chart.
- To assess testability rates, examination time, and predictive values of visual screening at different ages.
Main Methods:
- A prospective study involving 478 three-year-old children and 229 four-year-old children.
- Children were tested using both the HVOT chart and the Lea Symbol chart.
- Data collected included testability rates, testing time, and visual acuity assessment.
Main Results:
- Testability rates were high for both charts at age 4 (over 92%) and improved from age 3 (around 83%) to age 4 (around 96%).
- The Lea Symbol chart showed a slightly shorter, though not statistically significant, mean testing time.
- The positive predictive value for visual impairment was lower at age 3 (58%) compared to age 4 (74.6%).
Conclusions:
- Three-year-old children demonstrate good cooperation during visual acuity testing.
- Visual screening at age 4 yields higher testability rates and shorter examination times compared to age 3.
- Both the HVOT and Lea Symbol charts are equally effective for visual screening in 3- and 4-year-old children.
Purpose:
The aim of this prospective study was to compare visual screening at the age of 3 years with screening at 4 years using two different charts.
Methods:
A total of 478 3-year-old children were tested at four child health care centres (CHCCs). Of these children, 440 were tested again at the age of 4 years. A third group, a control group, consisting of 229 children, was examined only at the age of 4 years. All children were tested with both the HVOT chart and the Lea Symbol chart.
Results:
Testability rates for 3-year-olds were almost the same with the Lea Symbol chart and the HVOT chart (82.8% and 84.8%, respectively). The corresponding rates for the same children tested at 4 years of age were 96.5% and 97.0%, and for the 4-year-olds not previously tested 92.9% and 92.8%. The mean testing time was somewhat shorter for the Lea Symbol chart in all three groups, but the difference was not statistically significant. The difference in the assessment of visual acuity between the two charts was small and less than 1/10th of a line. The positive predictive value was lower at 3 years (58%) than has previously been found at 4 years (74.6%).
Conclusion:
Three-year-old children co-operate well in visual acuity testing. However, the examination time is a little longer and the testability rate is about 10% lower than at 4 years. Both 3-year-old and 4-year-old children can be tested equally well with the HVOT and the Lea Symbol charts.
