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Contrast sensitivity evaluation in a population-based study in Shahroud, Iran
Hassan Hashemi1, Mehdi Khabazkhoob, Ebrahim Jafarzadehpur
1Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran.
Ophthalmology
|December 14, 2011
Summary
Contrast sensitivity, a key measure of vision, declines with age, high myopia, and astigmatism. This study establishes normal ranges and determinants in a general population.
Area of Science:
- Ophthalmology
- Vision Science
Background:
- Contrast sensitivity is crucial for visual function and daily activities.
- Understanding normal ranges and influencing factors is essential for diagnosing visual impairments.
Purpose of the Study:
- To determine the normal range of contrast sensitivity in a population-based sample.
- To identify determinants of contrast sensitivity, including age, refractive errors, and visual acuity.
Main Methods:
- A population-based cross-sectional study was conducted in Shahroud, Iran.
- 6311 individuals aged 40-64 were sampled, with 5190 participants responding.
- Contrast sensitivity was measured using CVS1000 grating charts in 965 randomly selected participants.
Main Results:
- Mean contrast sensitivity varied across spatial frequencies, with significant declines observed with increasing age and lower uncorrected visual acuity.
- Women exhibited worse contrast sensitivity than men at lower spatial frequencies.
- High myopia (>5.0 diopters) and astigmatism were significantly associated with reduced contrast sensitivity.
Conclusions:
- The study provides reference values for contrast sensitivity in a general population.
- Age, high myopia, and astigmatism are significant factors affecting contrast sensitivity.
- Considerable variability in contrast sensitivity exists, even among individuals with normal visual acuity.
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