EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/137624
16 EW NEWS & OPINION June 2013 Increasing allergies worldwide will affect ophthalmologists by Vanessa Caceres EyeWorld Contributing Writer Current research focuses on allergy upswing and climate change F orget about "Got milk?"— how about "Got itchy eyes?" The impacts of global climate change will affect your practice going forward—and likely has already taken a toll. You'll see more patients with ocular allergies and common related conditions such as dry eye, said Leonard Bielory, MD, principal investigator for the U.S. Environmental Protection Agency (EPA) on climate change and allergic airway disease, Rutgers University, and attending, Robert Wood Johnson University Hospital, New Brunswick, N.J. Dr. Bielory's research has tracked dramatic changes in allergy rates over the past few decades and predicts more changes to come.1,2 For example, ocular and nasal allergy symptoms have more than doubled in the past 35 years, particularly for tree pollen, Dr. Bielory said. Other types of allergies also have increased in that time period, including food allergies. Although the exact connection is not clear, research seems to point to environmental factors that are prompting the increased allergic response, such as temperature increases, precipitation, and rising carbon dioxide concentrations. Poor air quality and increasing greenhouse gases will likely affect the number of people worldwide who are affected by ocular allergies or dry eye.1 Dr. Bielory's research indicates a possible 30% increase in pollen by 2030, although he notes that prediction fits a "perfect" test-tube world. Still, a pollen increase as well as increases in various other types of allergies are part of the future, which will naturally affect the number of people who suffer from allergies and how badly they suffer from it. Allergic diseases, including asthma, hay fever, rhinitis, and atopic dermatitis, already affect one third of the U.S. population, Dr. Bielory reported recently.1 Dr. Bielory gave a current example of how climate changes can affect allergies. For example, he explained why the allergy season has seemed particularly fierce so far this year, especially in the Northeast. It ties back to the effects of Hurricane Sandy. "In the Northeast, Hurricane Sandy saturated the ground and provided a lot of nutrients. That saturation inland helped trees to be well fed by the time they had their pollen production," he said. Ten years ago, an experiment spearheaded by Lewis H. Ziska, PhD, research plant physiologist, Crop Systems & Global Change, U.S. Department of Agriculture, was published and showed how pollen production would increase with climate change.3 In that study, Dr. Ziska and co-investigators planted ragweed in inner-city Baltimore as well as a nearby rural area. They did this because urban temperatures and carbon dioxide concentration levels would naturally be higher. They found that ragweed did indeed flower more rapidly in the urban area. "Ragweed grew faster, flowered earlier, and produced significantly greater above-ground biomass and ragweed pollen at urban locations than at rural locations," the investigators wrote. Research indicates that climate change has a greater impact in northern versus southern areas, Dr. Ziska said. However, that doesn't mean that warmer areas are left unscathed. For example, warmer yearround temperatures in a state like Florida, which tends to have a lot of moist air, leads to greater levels of mold—yet another allergic trigger, Dr. Ziska said. Dr. Ziska is currently working with Dr. Bielory to track the effect of carbon dioxide on summer weeds and allergenicity. Dr. Bielory's ongoing research with the EPA is focused, among other things, on growing plants at different concentrations of carbon dioxide at different temperatures to see if or how pollen levels, size, duration, and amount increase. Meanwhile, allergist Jeffrey G. Demain, MD, director, Allergy, Asthma & Immunology Center of Alaska, Anchorage, and associate clinical professor, University of Washington, Seattle, who also does research into allergy and climate change, has a true window into how increasing temperatures are affecting daily life. "We're on the front line of climate change here in Alaska," he said. Some examples include a proliferation of stinging insects, less viable caribou and seal hunting,