Causes Of Excessive Blinking In Children Aged 4-12 Years

Objective: This study aimed to investigate the causes of excessive blinking in children aged 4~12 years,which may provide evidence for the clinical treatment of abnormal blinking in children.Methods: A total of 578 children complaining of excessive blinking and aged 4 ~ 12 years were recruited from the ophthalmology clinic between December 2016 and November 2018,and 370 children without excessive blinking served as controls.Medical record and family history were reviewed,autorefractor,cycloplegic retinoscopy,allergen examinations were performed.The children with excessive blinking were divided into 3 age groups(4~6y,7~9y,10~12y).SPSS version 22.0 was used for the analysis of causes of excessive blinking.Results: Among 578 children with excessive blinking,there were 341boys(59.00%)and 237 girls(41.00%).Among children without excessive blinking,there 220(59.45%)boys and 150(40.55%)girls.Children with frequent blink may have a single etiology,and multiple etiology together.In children with excessive blinking,allergic conjunctivitis in 283(48.95%;188 boys and 95 girls),positive corneal fluorescein staining in247(42.73%;143 boys and 104 girls),conjunctival lithiasis/trichiasis in 37(6.40%;22 boys and 15 girls),refractive error in 78(13.49%;45boys and33 girls),tic disorder was found in 23 children(3.99%;16 boys and 7 girls).Mean time of video display terminal in the three age groups was respectively(1.27±0.55)h/d,(2.08±0.87)h/d,(2.82±0.94)h/d,the degree was respectively(1.47±1.61)D,(-0.49±1.37)D,(-1.00±1.10)D,breakup time of tear film was respectively(8.57±2.77)s,(8.44±2.49)s,(7.87±1.86)s.Allergen examination showed most children were allergic to dust mite(61.23%).There were significant differences in tear break-up time(r=-0.175,P<0.001),allergic conjunctivitis(r=-0.192,P<0.001),corneal epithelial injury(r=-0.103,P=0.013),diopter of children with ametropia(r=-0.607,P=0.001)and time of video display terminal(r=0.626P<0.001)among the three age groups,but no difference in conjunctival lithiasis/trichiasis(P>0.05)and tic disorder(P>0.05).Allergic conjunctivitis(r=-0.814,P<0.001),positive corneal fluorescein staining(r=-0.748,P<0.001),conjunctival lithiasis/trichiasis(r=-0.311,P<0.001),and time of video display terminal(r=-0.307,P<0.001)had a negative relationship with breakup time of tear film,but tic disorder(P>0.05)and gender(P>0.05)had no relationship with breakup time of tear film.Allergic conjunctivitis(r=0.769,P<0.001)and conjunctival lithiasis/trichiasis(r=0.153,P<0.001)had positive relationships with corneal fluorescein staining.Time of videodisplay terminal was positively related to the diopter of myopia-related ametropia(r=-0.141,P=0.001),and all were mild ametropia.The occurrence of frequent blinking is negatively correlated with children's age(r=-0.944,P<0.001)and is effected by sex(t=3.54,P=0.008),the number of boys with frequent blinking is more than girls.In addition,with no significant difference in the age,sex,and tear meniscus height between the two groups,there was significant difference in the breakup time of tear film between two groups(t=-4.43,P=0.047).Boys have more allergic conjunctivitis than girls,but allergic conjunctivitis as well as breakup time of tear film,corneal epithelium damage,conjunctival calculus/trichiasis,refractive error,tic disorder has no correlation with sex(P>0.05).Conclusion: Ocular surface diseases,refractive error,time of video exposure and tic disorder are the causes of excessive blinking.Of these factors,ocular surface diseases and time of video display terminal have relationships with breakup time of tear film.Moreover,these factors may interact with each other,causing the deterioration of excessive blinking.