Reflections on a Pioneering Vision Study
Adele Schneider, MD, director of Clinical Genetics at Einstein Medical Center Philadelphia, recently led a team of genetic researchers and vision experts to the island of Weno, part of Chuuk State in the nation of Micronesia, hoping to learn about the genetic underpinnings of anophthalmia/microphthalmia (A/M), which causes blindness in children.
They focused on trying to determine whether certain environmental factors might contribute to A/M, and provided badly needed ophthalmological services.
Dr. Schneider answered questions about the trip after returning to the U.S.:
Q. How many children did you see while you were in Chuuk?
A. We saw 29 families and some of them had more than one child. Altogether, we saw 32 or 33 children. Interestingly, though, there were three families from one of the outer islands, Tonoas. It turns out they have a different eye disorder which was diagnosed by the ophthalmologist. They had never had an eye exam.
Their eyes look small from the outside, but when we examined them their eyes were normal size, but they’re small because the kids poke them a lot and the fat around their eye has decreased.
So the eyes are sunken. They have a different disorder that will need to be studied, but one of the first cousins to that family also has microphthalmia.
The gene studies are going to be really, really interesting because there are those families on that island that are pretty closely related that have both disorders. We expect to solve that with gene studies.
Our theory is that everybody there is somewhat related, but we actually saw close relationships in some of the families that they knew about and talked about. If you live on a small island, you don’t have that much breadth, you know, in terms of the people that you are going to meet for marriage. The poverty there is just unbelievable. There isn’t a lot of mobility. People stay where they are. They stay local and they don’t have a lot going on there.
Q. How did you get the word out about the study?
A. Everybody has a transistor radio. That’s how they communicate. If they need information, there are certain times that they have to listen to get the Chuuk information. When they were recruiting families for our study, it was announced on the radio.
The other way, the priests announced it at church. That was so interesting. Everybody goes to church; everybody is very religious. Church is a big event. The priests have a lot of authority. If a priest announces something, the families will trust it.
Q. You said before the trip that you wanted to do more than conduct a study. You wanted to bring some immediate aid to the people of Chuuk. How did that work out?
A. This eye problem has been there a long time, and nobody paid attention until we came. Coming with an ophthalmologist was the best thing we did. Those kids had never seen an ophthalmologist. If they had an eye that worked a little bit, he looked at what prescription they could use, and he took that back with him and he found someone who would make glasses for them. He will send those back to them. That’s a big leap forward because the kids with at least one working eye will get glasses that will help their vision work with the residual vision they have.
Q. You went to Chuuk thinking that vitamin A deficiency might have something to do with the children’s vision problems. Do they have vitamin A deficiency, and how bad is it?
A. We got histories from the moms that showed that at least half, maybe more, had symptoms of vitamin A deficiency during pregnancy, with night blindness. When their pregnancies were over, their vision at night was better. That definitely shows that there is not enough vitamin A for the mother and the fetus.
Some of them have night blindness all the time, so they’re really deficient all the time. What we don’t know yet is where the gene that we find, whatever it will be, is influenced by the vitamin A level and why do some of the kids have bilateral anophthalmia and others have microphthalmia. Some have no eyes and are completely blind, some have small eyes and they have a little bit of vision, and is that in some way related to the mother’s vitamin A level? Our theory that vitamin A is in some way involved is probably right, but until we find the gene, we can’t be sure.
Q. Why are they vitamin A deficient?
A. They don’t have vegetables there. All the vegetables are imported. At the Chuuk Women’s Council they have a USAID program teaching people how to grow vegetables. They’re hoping people will have their own vegetable gardens at home and grow things like carrots and tomatoes, and in that way decrease the vitamin A deficiency. Finding the right amount of vitamin A is best done with the diet.
They also don’t have milk there. They have to import it. They don’t have the supplements from milk with vitamin A and D that we have.
Q. What else can be done to prevent these diseases?
A. The optimal thing would be for carriers (of the defective gene) not to marry each other. There is none of the sophisticated stuff you can do here to prevent the birth of an affected child if both parents are carriers. We need an education program and it is going to have to be through the teachers, the public health nurses, the priests and the doctors, and they’re all going to have to educate the community. We’re going to have to screen everybody, and the head pediatrician and the head of public health suggested that you do it routinely in 5th grade because kids tend to drop out after that. The goal will be, when the kids start dating, one of the first questions they will ask is: Are you a carrier?