Molecule may play a role in macular degeneration

Researchers have discovered a molecule known as interleukin-4 (IL-4) that is supposed to be anti-inflammatory and suppress blood vessel growth, but may actually do the opposite in people who have macular degeneration. A team of researchers at the Division of Ophthalmology and Visual Science at Tottori University in Japan published their findings in eLife.

The study involved 234 people with the wet form of macular degeneration and samples from the aqueous humor of 104 older people undergoing cataract surgery were used as controls. Researchers measured the levels of IL-4 in the aqueous humor in both groups and found that the people with the wet macular degeneration had higher levels of the IL-4 than the control group.

Researchers also examined mice that had a condition similar to macular degeneration and found that they had higher levels of IL-4 in their eyes. In order to see if IL-4 is actually harmful, the research team injected IL-4 into the bloodstream of the mice and found that it caused excessive blood vessel growth in their eyes. An antibody that blocks Il-4 production was then injected and it reduced the blood vessel growth.

The study findings will hopefully help to create treatments that could either block IL-4 directly or the receptors to which the molecule binds. Additional research, however, will be needed.