MONDAY, Aug. 13 (HealthDay News) -- Current and former smokers are much more likely to develop the eye disease age-related macular degeneration (AMD) than people who never smoked, an Australian study finds.

AMD, the leading cause of blindness in affluent countries, is a progressive disease that affects the central portion of the retina.

Researchers at the University of Sydney followed the 2,454 study participants for 10 years.

They found that, compared to nonsmokers, current smokers were four times more likely to develop AMD and former smokers were three times more likely to have "geographic atrophy," an advanced form of AMD.

Combinations of current smoking, low levels of HDL ("good") cholesterol, a high ratio of total cholesterol to HDL cholesterol, and low fish consumption were associated with a higher risk of late AMD than the effect of any risk factor alone, the researchers said.

"In summary, the findings from this large population-based prospective study add evidence to a possible causal relationship between smoking and the long-term risk of late, but not early, AMD," the researchers concluded.

The study is published in the journal Archives of Ophthalmology.

More information

The U.S. National Eye Institute has more about AMD.