Abstract
Purpose:
Yellow dust, also Asian dust, is originated from Northern China. The dust is picked up by the wind and spreads over China and some part of Japan. Yellow dust has been known as the major air pollutant affecting the respiratory organ in China. Increased number of acute conjunctivitis patients in Fukuoka, Japan during the season of yellow dust has been reported. Our study was to determine the presence of the yellow dust by analyzing the optically invisible small particulate matter in patients suffering from conjunctivitis and its correlation with clinical findings scores for conjunctivitis.
Methods:
Thirty eight patients [men : women = 23 : 15, 49.6 ±22.7 years old (mean ± S.D.) ] with newly diagnosed acute conjunctivitis from March 12 to May 24, 2013 in Fukuoka area were selected as candidates. The investigation period was based upon the weather report of the aerial yellow dust. The degree of inflammatory reaction, itchy sensation, hyperemia, lid swelling, were clinically recorded and scored. The eyes were washed by physiological solution and collected with a special collecting apparatus. Solid particles collected from the washing solution were observed by a scanning electron microscope. Ingredients of the particles were analyzed by X-ray scatter spectrometry. The results of material study and clinical findings score were analyzed.
Results:
Thirty seven out of thirty eight samples (97.4%) consisted of elements of Si and Al which were components of aerial yellow dust. The presence of the percentage of the yellow dust particle varied from 7 to 56 % (average= 26%). Higher clinical findings scores was observed in the subgroup with yellow dust/whole particulate ratio was higher than the average of 26%. (t-test : P<0.01, 9.0 vs 5.8, respectively)
Conclusions:
Presence of optically invisible small particles of yellow dust on ocular surface was confirmed in seasonal conjunctivitis. This is a first report on the correlation between the amount of yellow dust exposure on the ocular surface and the severity of clinical manifestations.
Keywords: 475 conjunctivitis