Light Therapy May Help Diabetics’ Vision

Sleeping with a light on may help prevent diabetics from developing a serious complication that can lead to blindness, according to a new study by British researchers.

The research, published last week in the British science journal the Lancet, suggests that even exposure to ordinary light levels through closed eyelids could prevent diabetic retinopathy, a condition that affects up to half of all diabetics.

Diabetes can damage tiny blood vessels in the light-sensitive tissue at the back of the eye, called the retina, causing them to weaken and cloud vision.

Diabetic retinopathy has no early warning signs. The blood vessels can bleed and leave a few specks of blood or spots which may disappear but sometimes do not clear. Large hemorrhages can happen more than once and often occur during sleep.

Standard treatments for the condition include laser surgery or, in advanced cases, an eye operation called a vitrectomy to remove the leakage. The drawbacks are that both treatments can be costly and can lead to side effects such as loss of peripheral vision.

Researchers from Cardiff University in Wales found that oxygen inhalation increased retinal cell activity. Exposure to light decreases the amount of oxygen consumed by the retina, lessening a diabetic’s chance of visual impairment.

When Neville Drasdo, a Cardiff researcher, and his colleagues studied the impact of nighttime light on seven patients with Type 2, or adult onset, diabetes and eight healthy volunteers, they found it helped to counteract the impact of the darkness in the diabetics.

The findings of the small study “encourage the belief that there may be a major breakthrough in the prevention of [diabetic retinopathy],” said Drasdo, a professor in the university’s department of optometry and vision sciences. “However, more research is needed before we could recommend immediate implementation of the idea. Some adverse effects might be possible.”

Drasdo said it is unknown at this stage how much of an effect sleeping with the lights on would have or what kind of light would be necessary.

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Reuters contributed to this report.