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Comparison of current paediatric contrast sensitivity assessments using simulated reduced contrast thresholds
Paula Amores Morillo1, Ashli Milling1, Anna O'Connor1
1Orthoptics, School of Health Sciences, Institute of Population Health, University of Liverpool.
Insights
The Double Happy (DH) test shows better agreement and sensitivity to contrast changes than the Hiding Heidi (HH) test, making it more suitable for clinical use in assessing contrast sensitivity.
Area of Science:
- Ophthalmology
- Visual Science
- Clinical Measurement
Background:
- Contrast sensitivity (CS) testing in children is limited.
- The Hiding Heidi (HH) test has a ceiling effect.
- The Double Happy (DH) test's ability to detect contrast changes is not well-established.
Purpose of the Study:
- Compare contrast thresholds and agreement between the HH and DH tests.
- Evaluate these tests against the Pelli Robson (PR) chart.
- Assess performance under normal, dim, and reduced visual clarity conditions.
Main Methods:
- 50 adult participants (age 18-62) were tested.
- Contrast sensitivity was measured uniocularly using PR, HH, and DH tests.
- Testing was conducted under bright (20,900 lux) and dim (2,000 lux) light, with and without simulation spectacles.
Main Results:
- 94% of participants reached the maximum score on the HH test, compared to 18% on the DH test.
- The reduction in CS under dim conditions was -0.21 logCS units for PR and DH, but only -0.04 logCS for HH.
- The DH test demonstrated better agreement with the PR chart than the HH test.
Conclusions:
- The DH test is superior to the HH test in detecting changes in contrast sensitivity.
- DH shows better agreement with the established PR chart.
- DH is recommended for clinical practice due to its improved performance and sensitivity.
Purpose:
There are limited tests of contrast sensitivity (CS) for use in children. The Hiding Heidi (HH) is suitable for all cognitive abilities, but has a ceiling effect. The Double Happy (DH) test has comparable thresholds to the Pelli Robson (PR), however the ability to detect changes in contrast has not been established. This study aims to compare contrast thresholds and agreement between HH and the DH, comparing to the PR chart in normal conditions and under reduced visual and lighting conditions.
Methods:
Tests were repeated under different conditions to reduce the contrast. Room illumination was 20,900{plus minus}2% lux in bright conditions and 2,000{plus minus}2% lux in dim conditions, both conditions were repeated with the addition of simulation spectacles to reduce the clarity of vision. Participants' CS was measured uniocularly using the PR, HH and DH tests.
Results:
50 participants, age 18-62 years (mean{plus minus}standard deviation: 24.5{plus minus}7.98), were assessed. On HH 94% (n = 47) reached the maximum score, with the DH it was 18% (n = 9). The difference in reduction between conditions was smaller with HH in comparison to PR and DH, but significantly different from baseline conditions. Under dim conditions the reduction in PR and DH was -0.21 logCS units, but only -0.04 logCS for HH.
Conclusion:
The DH test has better agreement with PR than HH and is better at detecting CS changes, highlighting the advantages of use in clinical practice.
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