NATIONAL - Macular degeneration is the leading cause of blindness in the US. But now, scientists have discovered a genetic variation in two genes that could one day lead to new treatments.
At age 90, former mountain climber Lewis l. McArthur is still hale and hardy. His eyesight's really his only ongoing health problem.
Lewis suffers from the wet form of macular degeneration. "I do have my peripheral vision, but I have a blindspot in the center of the left eye."
Dr. Peter Francis explains, "it's this area of the retina particularly that's affected in age-related macular degeneration."
There are two kinds of macular degeneration, wet and dry. Both cloud the vision and can lead to blindness.
Scientists have known for some time that genes play a big part in this disease. Now they've also discovered that variants in two genes in particular, can cause the disease to progress from bad to worse.
Dr. Francis says, "Having specific changes within those genes confirm a markedly increased risk of developing the advanced form of the condition."
These new genetic findings hold true for both wet and dry forms of the disease.
Lifestyle choices can also make matters worse. Dr. Francis says, "If you had the genetic variants that increase risk and you smoked and you're overweight you had an approximately 19-fold increase in your rate of progression to the blinding consequences of the disease."
Doctors now hope to develop new treatments and drug therapies to help stop what can be a devastating march towards blindness for almost two million Americans.
Recently, researchers discovered having one of the two genes in the study makes you six or seven times more at risk of the disease progressing.