New classification needed for urban conjunctivitis, presenter says

BUENOS AIRES — Although it has distinctly different characteristics than dry eye or allergic conjunctivitis, there is not a pathological diagnosis in existence for urban conjunctivitis due to ambient pollution, a presenter said here.

Alejandro Berra

"The principal Latin American cities — Santiago in Chile, San Paulo in Brazil, Mexico City in Mexico and Buenos Aires — present with ambient contamination levels higher than those recommended by the World Health Organization," Alejandro Berra, PhD, said at the Argentinean Society of Ophthalmology Annual Course.

He suggested that these pollutants could have a pathologic response in the eye, one that does not fall under allergic or dry eye diagnoses.

Gases such as carbon dioxide, nitrogen and oxygen, metals and particulate materials can be found in the atmosphere, in which the ocular surface comes into contact with 10,000 liters of air per day, he said.

Dr. Berra said there was a correlation between exposure to contaminated ambient gases and changes in the ocular surface in 8,377 patients from Buenos Aires who complained of ocular discomfort and irritation between 2000 and 2006.

In another study, when exposed to one quartile of nitrogen dioxide, 38.5% of patients complained of irritation, but when exposed to four quartiles, 92.9% complained of irritation, he said.

"All of these show that chronic exposure to environmental pollutants of large cities cause symptoms and signs in the ocular surface that can differentiate them from allergic conjunctivitis and dry eye," Dr. Berra said, suggesting that there should be a new classification for urban conjunctivitis due to ambient contamination.

Specifically, he said that irritation, rather than dry eye and itching, showed a statistically significant change. He said that pollution had a unique set of signs and symptoms when compared with dry eye, allergy and toxicity.