June 12, 2003 -- Age-related macular degeneration -- a major cause of blindness -- is much more dangerous in obese people.
But there's also some good news in the report by Harvard researchers Johanna M. Seddon, MD, and colleagues. They find that physical activity at least three times a week cuts the risk that macular degeneration will get worse.
The bottom line: People with macular degeneration should lose weight and exercise more. The study doesn't prove that this will prevent blindness. But the circumstantial evidence is very strong.
"These results have potential public health significance," Seddon and colleagues write in the June issue of the Archives of Ophthalmology. "A substantial number of people may benefit from these results. A decade ago, we had little advice for patients with age-related macular degeneration, and now we have an extensive body of evidence."
Seddon and colleagues followed 261 patients with mild age-related macular degeneration for an average of 4.6 years. All were at least 60 years old when the study began.
- Obese patients were more than twice as likely to get worse.
- The bigger a person's waistline, the higher the risk of vision loss.
- Exercising at least three times a week cut the risk of getting worse by 25%.
Age-related macular degeneration destroys central vision by damaging the part of the eye called the macula. The macula provides the clear, sharp, central vision that you use for focusing on what is in front of you. Everyday activities, such as reading, driving, and watching television require central vision.
SOURCE: Archives of Ophthalmology, June 2003.