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[Measurement of visual acuity in infants in 6 minutes: Teller's Acuity Cards]
1Service d'Ophtalmologie, CHLS, Pierre-Bênite.
Insights
Early detection of infant visual acuity is crucial for development. The Teller Acuity Cards offer a reliable and quick method for assessing visual acuity in preverbal infants, aiding early intervention for visual disorders.
Area of Science:
- Pediatric ophthalmology
- Developmental neuroscience
- Optometry
Context:
- Infant visual development peaks in the first year.
- Early detection of visual and oculomotor impairments like amblyopia is critical.
- Existing orthoptic and ophthalmological tests lack convenience for visual acuity measurement in preverbal infants.
Purpose:
- To introduce and evaluate the Teller Acuity Cards, a new commercial preferential looking test.
- To assess the reliability and convenience of the Teller Acuity Cards for measuring visual acuity in infants.
- To establish normative visual acuity data for infants aged 4-12 months using this new method.
Summary:
- The Teller Acuity Cards provide a rapid (5-6 minutes) and engaging method for estimating visual acuity in preverbal infants.
- Studies on 50 infants (4-12 months) showed higher grating acuity values compared to projection methods.
- Binocular acuity reached 13 cycles/deg (approx. 5/10) by 12 months, with monocular acuity being approximately half an octave lower.
Impact:
- Facilitates timely diagnosis and treatment of visual impairments in infants, preserving acuity.
- Highlights the importance of early (first year) therapeutic intervention when visual plasticity is highest.
- Offers a practical tool for pediatricians and ophthalmologists to monitor infant visual health effectively.
Abstract:
Most of the development of infant visual function occurs during the first year of life. Early pathological symptoms affecting visual or oculomotor processes, particularly ocular misalignment or amblyopia, should be detected and treated at the earliest age. Orthoptic and ophthalmological tests have been available for a long time but there remained a need for a convenient test for measuring visual acuity. Preferential looking techniques fulfill this demand and have been proven reliable and convenient to estimate visual acuity in preverbal infants. A new commercial presentation of the test, called Teller Acuity Cards, is described. Testing an infant was rapid, 5 to 6 minutes for a normal child, and easy because the child enjoys the convivality of the situation. Space requirement is reduced. Measures were taken from a population of 50 normal children aged 4 to 12 months. All children responded in the three situations, binocular and monocular (there was no blind eye in the group). Grating acuity values were higher than those obtained by projection preferential looking techniques. Binocular acuity was 6.5 cycles/deg (approximately 2.5/10) at 4 months of age, 9.8 cycles/deg (approximately 3.3/10) at 9 months and up to 13 cycles/deg (approximately 5/10) around 12 months. Acuities were found to be half an octave lower in monocular condition as compared to binocular. Orthoptic and ophthalmological check-up of infants is important, especially in case of children at risk of visual disorder. In most instances acuity can be preserved by therapeutic action provided it is initiated during the first year of life, when sensitivity to appropriate stimulation is at its peak.(ABSTRACT TRUNCATED AT 250 WORDS)