Recent Discovery Shows Progress Toward Curing Type of BlindnessBy Robert Cooke
Pioneering experiments in animals now show it's possible to block the damage that leads to diabetic retinopathy, the most common form of blindness in the working population, scientists report.
If treatments can be derived from the new findings, the researchers said, 25,000 Americans annually might be saved from blindness. The experiments show that eye damage can be blocked by keeping tiny blood vessels in the eye from growing abnormally.
After several years of study, two research teams have discovered independently that excess amounts of a hormone-like agent, VEGF, overstimulate the growth of tiny blood vessels in the eye. Now they've also found that blocking VEGF's activity can halt the damage in the animals' eyes.
Their discovery means that "in the next few years, the chances of a drug being used to inhibit the growth of blood vessels (in the eye) are very good," said ophthalmologist Lloyd Paul Aiello.
Aiello, at the Joslin Diabetes Center in Boston, and ophthalmologist Anthony Adamis, at Massachusetts Eye and Ear Infirmary and Children's Hospital, also in Boston, both have shown that abnormal growth of capillaries is what leads to bleeding, tearing and scarring of the retina, the light-sensing organ at the back of the eye. Blindness is the result.
Adamis could not comment on the findings, pending formal publication of his results Jan. 15 in the Archives of Ophthalmology, a scientific journal. The discovery was announced by Dr. Napoleon Ferrara, of the for-profit Genentech Inc. in San Francisco, who works with both Boston research teams.
Adamis and a collaborator, ophthalmologist Joan Miller, also at the Eye and Ear Infirmary, use monkeys to study the disease. Aiello and his colleagues are experimenting in mice, and have obtained very similar results, blocking retinopathy. Experiments in monkeys are generally considered to closely resemble what may be seen in humans.