Researchers at the University of Kentucky, led by Dr. Jayakrishna Ambati, have reached a breakthrough regarding geographic atrophy, related to dry age-related macular degeneration. Geographic atrophy, or GA, is an as-of-yet untreatable affliction resulting from the death of retinal pigmented epithelial cells, or RPE cells.
GA is a widespread cause of blindness that has affected millions.
Dr. Ambati is a professor of physiology, and professor and vice chair of ophthalmology at the University of Kentucky. He is a leading researcher in issues pertaining to macular degeneration.
Data collected by Ambati and a team of researchers, published in the publication Nature, show that there is a lack of enzyme DICER1 in human eyes with GA, which leads to an excess of harmful Alu RNA molecules in the retinal pigmented epithelium.
According to the paper Cell, these RNA molecules collect in the eye and thus activate an immune complex called the NLRP3 inflammasome. Consequently, this causes the production of the IL-18 molecule, which leads to death of retinal pigmented epithelial cells and loss of vision by triggering a critical protein, MyD88.
As found to be evident by Ambati and his colleagues, the inflammasome, IL-18, and MyD88 all have increased rates of activity in human eyes afflicted with GA. However, they indicated that cutting off these components could hinder or halt retinal degeneration in multiple disease models. The researchers are hopeful that these results could bring to light new therapy methods for GA, which still has no treatment. The market opportunity for developing treatments for GA is in excess of $1 billion.
Age-related macular degeneration stems from dry macular degeneration, which then advances and worsens to become “wet” macular degeneration (blood vessels impeding on the retina and causing loss of central vision) or geographic atrophy (the wearing away of, and damage to, photoreceptors in the eye). The eye conditions result in a blurring and loss of central vision, while maintaining healthy peripheral vision. This hinders activities such as reading, driving, writing, and recognizing faces.
The National Eye Institute, the Doris Duke Charitable Foundation, the Burroughs Wellcome Fund, and Research to Prevent Blindness, all supported the research.
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