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Hypo-accommodation responses in hypermetropic infants and children.
Anna M Horwood1, Patricia M Riddell
1School of Psychology and Clinical Language Sciences, University of Reading, Earley Gate, Reading, UK. a.m.horwood@reading.ac.uk
The British Journal of Ophthalmology
|July 7, 2010
Summary
Infants and children with hypermetropia show reduced accommodation, especially for near tasks. This suggests that some hypermetropic children may not need refractive correction to achieve normal vision.
Area of Science:
- Ophthalmology
- Pediatric Optometry
- Vision Science
Background:
- Accommodation plays a role in emmetropization, the process of developing normal vision.
- Understanding accommodation responses in hypermetropic children is crucial for guiding treatment strategies.
Purpose of the Study:
- To compare accommodation responses in emmetropizing infants and hypermetropic children.
- To identify characteristics and differences in accommodation across age groups and refractive conditions.
Main Methods:
- Utilized a PlusoptiXSO4 photorefractor in a laboratory setting.
- Collected binocular accommodation data from 38 infants (6-26 weeks) and compared with data from hypermetropic children (n=15), strabismus patients (n=14), and controls (n=27).
- Participants viewed a detailed picture target at distances ranging from 33 cm to 2 m.
Main Results:
- Hypermetropic individuals of all ages demonstrated under-accommodation compared to controls (p < 0.00001).
- Accommodation lag correlated with manifest refraction.
- Emmetropizing infants showed the greatest under-accommodation at distance, while hypermetropic groups under-accommodated most at near.
Conclusions:
- Hypermetropic children who naturally develop normal vision exhibit better near than distance accommodation.
- This finding supports a conservative approach to refractive correction in these children.
- Hypermetropic children with reduced distance acuity may not habitually accommodate to overcome under-correction.
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