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RESEARCH STUDY

RESEARCH

Visual Acuity and the Causes of Visual Loss in Australia. The Blue Mountains Eye Study

AUTHOR:

Karin Attebo

SPONSOR/INSTITUTION:

Australian Department of Health, Housing and Community Services, the Save Sight Institute, University of Sydney, the Ophthalmic Research Institute of Australia & the Western Sector Public Health Unit

YEAR PUBLISHED:

1996

PUBLICATION:

Ophthalmology

KEY HIGHLIGHTS:

  • Increasing age and female sex are independent predictors of visual impairment.

SUMMARY

The Blue Mountains Eye Study is a population-based study of vision and the causes of visual impairment and blindness in a well-defined urban, Australian population 49 years of age and older.


Refraction improved visual acuity by one or more lines in 45% of participants and by three or more lines in 13%. Visual impairment (visual acuity 20/40 or worse in the better eye) was found in 170 participants (4.7%). Mild visual impairment (Snellen equivalent 20/40 to 20/60 in the better eye) was found in 3.4%, moderate visual impairment (20/80 to 20/160 in the better eye) in 0.6%, and severe visual impairment or blindness (20/200 or worse in the better eye) in 0.7%. Visual impairment increased with age from 0.8% of persons 49 to 54 years of age to 42% of persons 85 years of age or older. Visual impairment was significantly more frequent in females at all ages.


Among persons with severe visual impairment, 79% were female. After adjusting for age, females were less likely to achieve 20/20 best-corrected visual acuity than males (odds ratio, 0.57; confidence interval, 0.48-0.66). After adjusting for age and sex, no association was found between visual acuity and socioeconomic status. Age-related macular degeneration was the cause of blindness in 21 of the 24 persons with corrected visual acuity of 20/200 or worse.


Conclusion: Increasing age and female sex were independent predictors of visual impairment.