Researchers at Columbia University have synthesized large quantities of a derivative of vitamin A that accumulates with age in human eyes and may contribute to the onset of age-related macular degeneration.
The Columbia team also was able to isolate and quantify compounds from individual donor eyes, including the vitamin A derivative, called A2E. Quantification of A2E in human cells could allow for a direct correlation of the amount of this material with macular degeneration. The work appears in the Dec. 8 issue of the Proceedings of the National Academy of Sciences.
The new synthesis is critical to biological and chemical experiments needed to pinpoint the relationship between A2E and age-related changes in the retina, the scientists say. The synthesis uses simple starting materials and can provide a 50 percent yield of A2E, an enormous increase over previous methods. Now, laboratories at Columbia and elsewhere will be able to make enough of the compound to forge ahead in the quest to understand the disease. The Columbia team already has developed several hypotheses describing the role of A2E in macular degeneration and is proceeding with experiments to refine their understanding.
"Although we are not certain that A2E is implicated in macular degeneration, it is certainly a leading candidate," said Craig Parish, a postdoctoral chemistry researcher at Columbia and first author of the work. Other collaborators, all at Columbia, were Masaru Hashimoto, postdoctoral chemistry researcher; Koji Nakanishi, Centennial Professor of Chemistry, and Janet Sparrow and James Dillon, associate professors of ophthalmology at Columbia's College of Physicians & Surgeons.
Age-related macular degeneration, or AMD, is believed to cause severe
visual impairment or blindness in approximately 1.7 million of the 34 million
Americans over the age of 65 and is the leading cause of blindness in that age
group, according to the Nati
Contact: Bob Nelson