Yellow foveal pigment could be key to AMD

A tiny yellow pigment may be the main thing standing between many older people and macular degeneration, according to a study at the Medical College of Georgia in Augusta.

By measuring this macular pigment that sits on the fovea, Dr. John Nolan, vision scientist at the MCG department of ophthalmology, hopes to better understand what a healthy, normal pigment looks like.

The idea is that thinning of this pigment, comprised of yellow antioxidants that come from food or dietary supplements, opens the door for retinal cell destruction, the hallmark of macular degeneration.

The hope is that measuring this protective pigment will one day be part of routine vision screening.

Dr Max Snodderly, another vision scientist at MCG, said: ‘This pigment is thought to protect the retina from damage by light and excess oxidation, which over a lifetime can accumulate and contribute to the process of macular degeneration.’

Dr Snodderly's studies of monkeys raised on a synthetic diet lacking components of the pigment - lutein and zeaxanthin - showed they also lacked the pigment until the components were added to the diet. ‘The retina was able to take it up, even though it had never seen it before,’ he said of the natural pigments found in dark green leafy vegetables such as spinach, turnips and collards, as well as fruit and egg yolk.

Studies of more than 800 people age 20-60 with good vision in Ireland have parallel findings: that the protective macular pigment can be increased with dietary change and/or dietary supplements of lutein and zeaxanthin.

Dr Nolan’s studies, based at the Waterford Institute of Technology, included a subset of 200 people with healthy vision whose parents had macular degeneration.

‘This group with perfect vision had significantly lower levels of macular pigment than the control group. This reinforces the macular pigment story,’ he said.