Nearly 40 years ago, ophthalmologist Dr. Alfred Sommer moved his young family to Indonesia to confront an epidemic of xerophthalmia, a childhood blinding disease caused by vitamin A deficiency. He had no idea his work would end up saving not only the eyesight, but also the lives of millions of children in developing countries for decades to come.
Sommer, now dean emeritus of the Bloomberg School of Public Health at Johns Hopkins University, talked about that work and more at the Global Health Vision Lecture sponsored recently by NEI’s Office of International Program Activities. The talk drew an audience from 18 countries where people tuned in to watch it by live videocast.
Sommer explained that vitamin A is critical for making rhodopsin. A pigment in cells of the light-sensitive retinal tissue at the back of the eye, rhodopsin is important for low
light vision. Anyone who has ever stepped from a sunny place to a dark one knows it takes a few minutes for your eyes to adjust before you can see anything. During those first moments in the dark, your eye is regenerating rhodopsin. Someone who is vitamin A-deficient isn’t able to generate it and experiences night blindness. When vitamin A deficiency is more severe, the cornea can become dry and skin-like. When left untreated, the cornea can develop ulcers and even melt entirely, leading to severe inflammation and blindness.
In the 1970s, when Sommer was working in Indonesia, the World Health Organization’s recommended care for xerophthalmia was to administer a water-based vitamin A solution by injecting it into muscle. However, water-based injectable preparations were not even commercially available. Seeking an alternative, he discovered that oil-based vitamin A supplements were readily available, inexpensive and just as effective for preventing and curing xerophthalmia.
By Sommer’s calculation, 2 cents worth of oral vitamin A per patient could help prevent the country’s more than 63,000 new cases—and Asia’s 500,000 new cases—of corneal ulcers each year and prevent the associated blindness.
But it was another discovery that would forever change WHO policy on vitamin A supplementation in poor and underserved parts of the world.
NEI director Dr. Paul Sieving (l) and NEI deputy director Dr. Belinda Seto welcome Dr. Alfred Sommer (second from r) to NIH. Sommer’s lecture was arranged by Dr. Gyan Prakash (r), associate director of NEI’s Office of International Program Activities.
Photo: Sherrita Walls
A few years after returning home to the U.S., digging through reams of data from an 18-month follow-up study of mild xerophthalmia among 5,000 Indonesian children, Sommer spotted a pattern: Many children who had reported night blindness at baseline were not around for follow-up visits months later. That’s because they had died at a staggering three-fold greater rate compared to children without any signs of the eye disease. Children who at baseline had Bitot’s spots (foamy white lesions on the surface of the eye that are associated with slightly more severe vitamin A deficiency than night blindness and develop as the cells lose their mucus membrane layer) had a six-fold increase in mortality.
“I thought, ‘Holy cow, what’s going on here?’” Sommer said.
Initially, the assumption had been that night blindness and Bitot’s spots were warning signs of mild vitamin A deficiency. Yet children with these supposedly “early” warning signs were dying at much higher rates than were children without the early signs. Even after adjusting for other factors, such as malnutrition and pneumonia, he found a strong relationship between vitamin A deficiency and death.
Further research conducted by Sommer and his team revealed that the children were dying primarily from measles and severe diarrhea and that vitamin A deficiency was likely increasing their vulnerability to these conditions.
By 1992, large-scale, randomized controlled trials in Nepal, Indonesia and India shored up the evidence: Preventing vitamin A deficiency decreased all-cause mortality by one-third, while treating children already suffering from severe measles with oral vitamin A reduced their case-fatality rate by 50 percent.
“Now…we can look back on that remarkable finding and say that Dr. Sommer saved the lives of more children than any other person,” said NEI director Dr. Paul Sieving. Sommer received a Lasker Award in 1997 for this research.
In addition to his work on xerophthalmia, Sommer has conducted research on other blinding eye diseases worldwide.
Efforts to treat and eradicate trachoma, a leading infectious cause of blindness in the developing world that scars the inside of the eyelid, causing eyelashes to turn inward and scrape against the cornea, brought Sommer to Bedouin communities of Saudi Arabia and to remote villages in Chiapas, Mexico. From a survey comparing children in Chiapas with and without trachoma, the key difference turned out to be the frequency with which they washed their faces with water. This simple intervention became a core of the public health trachoma strategy known as SAFE (surgery, antibiotics, facial cleanliness and environmental hygiene).
The Global Health Vision Lecture series is also sponsored by the NIH global health interest group and Fogarty International Center. To watch a videocast of Sommer’s lecture, visit http://videocast.nih.gov/summary.asp?Live=15252&bhcp=1.