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Accommodative response in pre-presbyopes with visual impairment and its clinical implications
1School of Optometry, University of Waterloo, Waterloo, Ontario, Canada.
Investigative Ophthalmology & Visual Science
|July 27, 2007
Summary
Reduced eye accommodation is common in individuals with low vision, with deficits increasing with demand. This accommodation impairment is not linked to age or visual acuity, suggesting complex underlying factors.
Area of Science:
- Ophthalmology
- Vision Science
Background:
- Isolated reports indicate reduced accommodative response in low vision populations.
- Understanding factors influencing accommodation in visually impaired individuals is crucial.
Purpose of the Study:
- To quantify accommodative response in a diverse group of pre-presbyopic individuals with low vision.
- To identify potential factors affecting accommodation within the low vision population.
Main Methods:
- Dynamic retinoscopy measured accommodative responses to demands of 4-10 D.
- Compared 21 low vision subjects (ages 3-35) with 40 age-matched controls.
- Calculated accommodative function slope and mean error.
Main Results:
- 86% of low vision subjects exhibited accommodative responses outside the normal range.
- Accommodation deficit worsened with higher accommodative demands.
- Impairment was independent of age, visual acuity, nystagmus, refractive error, or onset time.
Conclusions:
- Accommodative response in low vision is influenced by multiple interacting factors.
- Accommodation errors in low vision can exceed predictions based on depth of focus.
- Further research is needed to elucidate the complex mechanisms involved.
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