AIM: To study the relationship between blood lead level and abnormal eye blinking in children.

METHODS: The patients with chief complaint of frequent eye blinking, whose diagnosis of abnormal eye blinking, were randomized to experimental group. The patients in this group carried out vision and the slit-lamp examination, detected corneal fluorescein staining and tear break-up time, and improved the level of blood lead and trace elements examination. The patients in control group with chief complaint of health physical examination in our hospital, excepted of blood lead level, the other body check results were normal and were divided into boys group and girls group according to the gender. The changes of the experimental group and control group in blood lead level were compared.

RESULTS: Totally 371 cases(male: 295 cases; female: 76 cases)with mean age was 6.56±2.41 years and 6.08±2.82 years respectively were in experimental groupe. In control group, there were 300 cases(male: 186 cases; female: 114 cases)with mean age was 6.99±3.01 years and 6.56±2.80 years respectively. The average of blood lead level of boys in experimental group was 63.82±24.56μg/L and 53.98±15.42μg/L in control group. The average of blood lead level in experimental group was higher than that in control group. The difference between of the two group was statistically significant(χ²=16.96, P<0.01). The average of blood lead level of girls in experimental group was 56.96±16.69μg/L and 48.18±12.35μg/L in control group. There was no difference between of the two group(χ²=5.77, P=0.56). In control group, the average of blood lead level with <3 years, 3～6 years and >6 years children were 48.73±11.67μg/L, 51.39±14.87μg/L,52.98±14.45μg/L respectively. In expirement group, the results were 56.57±17.89μg/L, 59.92±18.46μg/L and 67.00±32.55μg/L in <3, 3～6 and >6 children, respectively. There was no significant difference with <3 years(χ²=3.54, P=0.17). The difference with 3～6 years and >6 years children were statistically significant(χ²=9.62, P=0.008)and(χ²=19.22, P=0.000)respectively. The blood lead level were divided into three grades: <50μg/L, 50～100μg/L, >100μg/L, and relative risk(RR)were 0.65, 1.22, and 10.11 respectively.

CONCLUSION: Blood lead level of experimental group is higher than that of control group. The relationship between blood lead level and abnormal eye blinking in children is positive correlation.