Scientists studied a common eye disease called AMD that causes blindness in older people around the world. They looked at data from 1990 to 2021 to understand who gets this disease and why. They found that AMD is a bigger problem in poorer countries and affects more women than men. Interestingly, they discovered that certain fats in your blood might protect you from AMD, while others might increase your risk. The study suggests that as populations grow and age, more people will develop this eye disease unless we take action to prevent it.

The Quick Take

  • What they studied: How common age-related macular degeneration (AMD) is around the world, who gets it most, and what blood fats might protect or harm your eyes
  • Who participated: This wasn’t a traditional study with volunteers. Instead, researchers analyzed global health data collected from 1990 to 2021 from countries around the world, looking at patterns in millions of people
  • Key finding: AMD causes about 570,000 years of lost health worldwide each year. The disease is much more common in poorer countries, especially in Africa. Women experience more vision loss from AMD than men. Surprisingly, higher triglyceride levels (one type of blood fat) may protect against AMD, while higher HDL cholesterol (often called ‘good’ cholesterol) may increase risk
  • What it means for you: If you’re over 50, especially in a developing country, you should get regular eye exams. The findings about blood fats are interesting but need more research before changing your diet or medications. Talk to your doctor about your personal risk factors

The Research Details

Researchers didn’t conduct a new experiment with people. Instead, they gathered and analyzed existing health information from the Global Burden of Disease database, which tracks health problems across the world from 1990 to 2021. They looked at how many people had AMD, how severe it was, and how these numbers changed over time in different countries and regions.

They also used a special statistical method called Mendelian randomization to study whether certain blood fats actually cause AMD or just happen to be present when people have it. This method uses genetic information to figure out cause-and-effect relationships that are hard to prove in regular studies.

The researchers examined patterns by age, sex, and how wealthy different countries are. They also made predictions about what might happen by 2045 if current trends continue.

This approach is important because it shows the big picture of AMD worldwide rather than just in one hospital or country. By looking at trends over 30 years, scientists can see whether the problem is getting better or worse. The genetic analysis helps explain why some people get AMD while others don’t, which could lead to better prevention strategies

This study used data from a well-respected global health database that many countries contribute to, making it reliable for worldwide patterns. However, the study couldn’t prove cause-and-effect for all findings because it analyzed existing data rather than conducting controlled experiments. The genetic analysis (Mendelian randomization) is a strong method but works best when confirmed by other studies

What the Results Show

In 2021, AMD affected about 94 people per 100,000 worldwide, and caused about 570,000 years of lost health globally. The good news is that AMD rates have been slowly decreasing since 1990, but scientists predict this trend may reverse and rates could go up by 2045 as populations age.

The disease burden is not evenly spread around the world. Poorer countries, especially in sub-Saharan Africa, have much higher rates of AMD and more severe vision loss. Women experience more disability from AMD than men at every age group studied.

When researchers looked at blood fats, they found something unexpected: higher triglyceride levels (a type of fat in your blood) appeared to protect against AMD. For every increase in triglyceride levels, AMD risk dropped by about 18%. In contrast, higher HDL cholesterol (often promoted as ‘good’ cholesterol) seemed to increase AMD risk by about 15%.

The study found that population growth and aging are the biggest drivers of AMD cases worldwide. As countries develop economically, AMD rates tend to decrease, suggesting that better healthcare, nutrition, and living conditions help prevent the disease. The analysis showed that AMD affects people starting in middle age but becomes much more common in people over 75

This research confirms what other studies have shown: AMD is a major cause of blindness in older adults and is a bigger problem in developing countries. However, the findings about blood fats are surprising and somewhat contradict common health advice that higher HDL is always protective. This suggests that the relationship between cholesterol and eye health may be more complex than previously thought and needs further investigation

This study analyzed existing data rather than following people over time, so it can’t prove that blood fats directly cause AMD changes. The genetic analysis is strong but needs to be confirmed by other research. The study couldn’t account for all possible factors that might affect AMD risk, such as smoking, sun exposure, or diet quality. Different countries may report health data differently, which could affect accuracy. The predictions for 2045 assume current trends continue, but new treatments or prevention methods could change this

The Bottom Line

Get regular eye exams starting at age 50, especially if you have family members with AMD (moderate confidence). Maintain a healthy diet rich in leafy greens and fish, which previous research suggests may help eye health (moderate confidence). Don’t make changes to your cholesterol medications based on this study alone—talk to your doctor first (high confidence). If you live in a developing country, prioritize access to eye care and early screening (moderate confidence)

Anyone over 50 should know about AMD risk, especially women and people in developing countries. People with family history of AMD should be extra vigilant. People taking cholesterol medications should discuss this research with their doctor but shouldn’t change medications without medical guidance. Healthcare policymakers in low-income countries should use this data to plan eye care services

AMD develops slowly over years, so you won’t notice changes overnight. Regular eye exams can catch early signs before vision loss occurs. If you make dietary changes, it may take months to years to see any benefit. The predictions in this study extend to 2045, showing this is a long-term health challenge

Want to Apply This Research?

  • Log eye exam dates and results, including any early AMD signs noted by your eye doctor. Track this annually starting at age 50
  • Set a reminder for annual eye exams. If you’re over 50, schedule an appointment with an eye care professional if you haven’t had one in the past year
  • Keep a record of eye exam findings over time. Note any changes in vision, such as difficulty reading or blurred central vision. Track this alongside general health metrics like cholesterol levels and diet quality

This research provides important information about AMD patterns worldwide but should not replace professional medical advice. The findings about blood fats and AMD are preliminary and need confirmation through additional research. Do not change your cholesterol medications or diet based solely on this study—consult with your doctor or eye care specialist about your individual risk factors and treatment options. This study analyzed global trends and may not apply to your specific situation. If you experience vision changes, blurred central vision, or difficulty reading, contact an eye care professional immediately