Just as people affect one another by communication. So do all the cell types in the body. Yes, there have been some epidemiologic studies of people who have dry eye syndromes for instance. There are some people here at our institute who are involved in those kinds of studies. In terms of demography and regional variations, we know that there are seasonal variations in how the ocular surface is affected.
Allergic conjunctivitis is obviously a big problem with ocular surface and that is seasonal.
And in terms of regional variations, places that are hot, dry, when you are exposed to a lot of dust, that sort of thing, people have a predilection to ocular surface drying. Q. How about age. I think are probably over 50. There is a predilection for postmenopausal women to have dry eye syndrome. People are looking towards understanding hormone regulation of these epithelial activities.