The Prevalence Of Ocular Demodex Folliculorum And Influencing Factors In Healthy Young Males

ObjectiveTo investigate the prevalence and influencing factors of Demodex folliculorum in the eyelashes of healthy young males,and evaluate the relationship between Demodex folliculorum and ocular symptoms.MethodsA crowd-based prevalence survey using cluster sampling was conducted.We established a survey site in September 2019 at the 2nd outpatient department of the900th Hospital of PLA.We conducted visual acuity,eye-related examination,eyelash microscopic examination and Demodex folliculorum count of recruits in Fujian Province in 2019.A sample of 6 eyelashes was taken aseptically from left eye of the subjects and studied under a light microscope.The presence of Demodex folliculorum of any stage in at least one of the 6 eyelashes was defined as Demodex-positive.The presence of Demodex folliculorum was analyzed according to age,myopia correction surgery,annual household income,educational level,long-term residence,sleep time,time of using electronic products,smoke and drinking habits.χ~2test and logistic regression analysis were used to analyze the data.ResultsA total of 2253 males were included in this study,with an average age of19.61±1.52.The prevalence of Demodex folliculorum was 20.73%(467/2253).The positive rate of upper eyelid and lower eyelid were 63.60%and 50.54%,respectively.A total of 846 Demodex folliculorums were detected,the degree of upper and lower eyelid detection was 0.35 and 0.24 per eyelash,respectively.Subjects with previous history of myopia correction surgery had a statistically significant increase in the detection rate of Demodex folliculorum(P<0.001).The detection rate was higher in patients with ocular symptom than in those without symptoms,and the difference was statistically significant(P<0.05),but the detection degree was the same,all being 0.30 per eyelash.There was no significant difference in the detection rate of Demodex folliculorum among subjects with different educational levels,annual household income,long-term residence,sleep time,time of using electronic products,smoke and drinking habits(all P>0.05).According to the multivariate logistic regression analysis,the history of myopic surgery was the risk factors of Demodex folliculorum positive(P<0.001),and the risk of infection was 1.437 times higher in the population with the history of myopic correction surgery than in the population without.There was no correlation between ocular symptom and Demodex folliculorum positive(P>0.05).Conclusion1.The detection rate of Demodex folliculorum of healthy young males was relatively high,attention should be paid to the ocular Demodex in this population.2.The detection rate of Demodex folliculorum on upper eyelid was higher than lower eyelid.It was suggested that upper eyelid eyelash can improve the detection rate in optical microscope examination.3.The history of ocular surgery was an independent risk factor for Demodex folliculorum infection.For people who have undergone ocular surgery,more attention should be paid to preventing Demodex infection.4.Education levels,long-term residence,annual family income,smoking and drinking habits,use of electronic products and sleep time had no influence on the detection rate of Demodex folliculorum.5.No correlation between ocular symptom and Demodex folliculorum infection had been found in healthy people.But the possibility of latent infection cannot be ruled out.The relationship between the two needs to be further clarified.