By Xinhua
Washington : US researchers say they have created the first animal model of age-related macular degeneration (AMD), an important first step in developing treatments.
AMD is the most common cause of vision loss in elderly people, affecting more than 10 million people in the US and about 50 million worldwide.
The study, which appeared in the October issue of Human Molecular Genetics, said that some forms of the AMD are inherited, and one type is thought to be caused by a mutation in the Efemp1 gene.
The researchers at the University of Pennsylvania created a mouse model of this inherited disorder by introducing the disease-causing mutation into the Efemp1 gene of mice. The resulting Efemp1-mutant mice developed the same basal deposits in its eyes as people with the AMD.
“By making this particular mutant mouse, we’ve made a model of early macular degeneration that’s caused by a mutation we know produces macular degeneration in people,” said lead author Eric Pierce. “It’s going to be a good model to study the pathogenesis of basal deposits.”
Although the AMD is a common and debilitating condition, prevention and treatment options are limited because it is a difficult condition to study.
The AMD develops late in life — patients typically show symptoms of the AMD after 60, and the only samples researchers could use for study were from people who died while they had the early stages of the AMD. At that point, the tissue is of no use for studying the progression of the condition.
“To better develop treatments for preventing the progression of the AMD, we need to understand the real biochemical details of how the AMD occurs,” said Pierce. “To do that, we need a model, and now we have one.”
The research team now plans to use the Efemp1-mutant mice to study how basal deposits form and what they are made of. The mice can also be used to test potential treatments to prevent basal deposit formation.