Prevalence of Age-Related Macular Degeneration in Indigenous and Nonindigenous Australians
Understanding Age-Related Macular Degeneration
Age-related macular degeneration (AMD) is a significant contributor to irreversible blindness in Australia and the western world. This condition affects the macula, a highly pigmented area of the eye crucial for high-resolution, colored vision. In addition to its impact on vision, AMD detracts from quality of life and imposes substantial economic costs, totaling approximately $750 million annually for the Australian government. AMD can be categorized into two types: dry (atrophic) macular degeneration, marked by small deposits on the retina, and wet (neovascular) macular degeneration, which results from abnormal blood vessel growth near the macula.
Importance of Studying AMD Prevalence
Investigating the prevalence of AMD is essential for developing effective policies to provide quality eye care for the Australian population.
National Eye Health Survey Overview
Study Design and Participants
The National Eye Health Survey (NEHS), published in JAMA Ophthalmology, was a comprehensive population-based study conducted from March 2015 to April 2016. The survey focused on the prevalence and causes of vision impairment and blindness among both indigenous and nonindigenous Australians. A total of 4,836 participants were recruited, including 3,098 nonindigenous Australians aged 40 to 92 years and 1,738 indigenous Australians aged 50 to 98 years.
Data Collection Methods
Information was gathered through an interviewer-administered questionnaire that assessed sociodemographic factors, ocular health, and medical histories. AMD was classified following the Beckman classification system, categorizing it into early, intermediate, or late stages.
Findings of the NEHS
Prevalence Rates
The study revealed that the overall prevalence of age-related macular degeneration was lower among indigenous Australians compared to their nonindigenous counterparts.
Associated Risk Factors
In the nonindigenous population, AMD was linked to several factors, including older age, male sex, European ethnicity, and living in geographically isolated areas. For the indigenous population, associated factors included older age, male sex, lower educational attainment, and self-reported history of stroke. After adjusting for various covariates, age remained a significant factor influencing AMD prevalence in both groups, while self-reported stroke continued to be a risk factor for intermediate AMD among indigenous individuals.
Conclusions and Implications
Comparative Insights
The NEHS findings indicate a lower prevalence of AMD in indigenous Australians, aligning with studies from the United States that report similar trends among African American and Latino populations. The reduced occurrence of AMD in these groups may be attributed to the protective effects of melanin against oxidative damage.
Healthcare Recommendations
The survey also highlighted that a substantial number of both nonindigenous and indigenous Australians with intermediate AMD had not consulted an optometrist or ophthalmologist in the past year. To enhance early detection of age-related macular degeneration, healthcare policies should focus on public education and encourage regular eye examinations.
Author and Citation
Written by Haisam Shah, BSc.
Citation: Keel, S., Xie, J., Foreman, J., van Wijngaarden, P., Taylor, H. R., & Dirani, M. Prevalence of Age-Related Macular Degeneration in Australia: The Australian National Eye Health Survey. JAMA Ophthalmology.