Clinical effect of Chinese medicine aerosol fumigation on demodex infection related meibomian gland dysfunction

Xiao-Yu Hou,Ya-Li Qin,Ting-Ting Deng,Ming Jin✉

1.Beijing University of Chinese Medicine,Beijing 100029,China

2.Zhongshan Ophthalmic Center,Sun Yat-sen University,Guangzhou 510060,China

3.China-Japan Friendship Hospital,Beijing 100029,China

Keywords:Demodex Meibomian gland dysfunction Chinese medicine Aerosol fumigation

ABSTRACT Objective:To explore the clinical effect of Chinese medicine aerosol fumigation on demodex infection related meibomian gland dysfunction.Methods:In this prospective study,60 patients(120 eyes) were selected and randomly divided into 2 groups:the treatment group(30 cases,60 eyes) was treated with Chinese medicine aerosol fumigation and meibomian gland massage,the control group(30 cases,60 eyes) was treated with meibomian gland massage.Observation of Demodex count,symptom scores,break-up time (BUT),Schirmer I test (SIT),meibomian gland secretion function scores and eyelid fat traits scores were used to compare the difference between before and after treatment.Results:There was no significant difference in Demodex count,symptom scores,BUT,SIT,meibomian gland secretion function scores and eyelid fat traits scores between the 2 groups before treatment(P>0.05).After treatment,symptom scores,meibomian gland secretion function scores and eyelid fat traits and Demodex count of the treatment group were significantly reduced(P<0.01).Conclusion:Chinese medicine aerosol fumigation can relieve symptoms of of demodex infection related meibomian gland dysfunctionand reduce the number of ocular Demodex.

1.Introduction

Meibomian gland dysfunction (MGD) is a chronic diffuse meibomian gland disease,it can damage tear film and cause ocular surface inflammation,resulting in eye discomfort.In severe cases,it may damage the cornea and affect the visual function [1].Demodex infection is closely related to MGD,and the positive rate of demodex in MGD patients in China is 57.0%～ 89.3%[2-3].Demodex folliculorum is a permanent parasitic mite,which can be divided into Demodex folliculorum and Demodex brevis [4].Clinical studies have found that the severity of demodex infection is positively correlated with meibomian gland loss,and can aggravate ocular discomfort [3].At present,tea tree oil and metronidazole are commonly used as anti-mite drugs in China [5].Tea tree oil has a certain inhibitory effect on demodex mite,but it is potentially toxic to human meibomian epithelial cells [6].Although oral metronidazole or external metronidazole has certain curative effect on demodex mite,improper use of metronidazole may cause dizziness,nausea and other systemic side effects [7].Traditional Chinese medicine external treatment has the advantages of simple use and less adverse reactions.Traditional Chinese medicine ophthalmology has a long history of using traditional Chinese medicine external treatment[8].With the increase of people's attention to Ocular demodicidosis,there have been many reports on the experimental studies on the inhibition of demodex by Chinese medicine in vitro,but there are few reports on the clinical prevention and treatment of demodex ophthalmoides by Chinese medicine.In this study,the effects of ultrasonic atomization of Traditional Chinese medicine on the ocular surface of MGD patients infected by demodex were observed.The ocular surface demodex count,ocular surface symptom score,tear film rupture time (BUT) score,tear secretion test (SIT) score,meibomian gland secretion function score and meibomian gland secretion character score were used as the observation indicators.In order to provide a reference for the clinical treatment of demodex related ocular surface diseases,the efficacy of ultrasonic atomization of Traditional Chinese medicine in the treatment of MGD patients infected by demodex was evaluated with 2 weeks as the treatment cycle.

2.Materials and Methods

2.1 Research objects

This study is a prospective study.60 patients (120 eyes) with MGD complicated with demodex infection treated in our hospital from April 2020 to January 2021 were randomly divided into experimental group and control group.Among the 60 cases,there were 22 males(44 eyes) and 38 females (72 eyes),aged from 24 to 80 years,with an average of 45.28 ± 18.22 years.The study was approved by the clinical research ethics review committee of China Japan Friendship Hospital (ethics batch No.:2020-12-k09).

2.2 Diagnostic criteria,inclusion criteria and exclusion criteria

2.2.1 diagnostic criteria of MGD

Refer to the diagnostic criteria proposed in the consensus of experts on the diagnosis and treatment of meibomian gland dysfunction in China (2017) [1] and ophthalmology [9].

2.2.2 Positive diagnostic criteria for demodex infection[6]

①Demodex in each stage was counted;② The Demodex count of any one of the four eyelids in adult patients reached 3/ 3 eyelashes.

2.3 Inclusion criteria

(1) They were between 18 and 80 years old,volunteered to take the test and signed the informed consent form;

(2) It meets the diagnostic criteria of MGD in China;

(3) It meets the positive diagnostic criteria of Demodex infection;

(4) Able and willing to accept the initial baseline evaluation and study follow-up in all time periods after treatment (baseline,2 weeks of treatment).

2.4 Exclusion criteria

(1) Allergic to therapeutic drugs;

(2) Entropion,ectropion,eyelid edema,eyelid spasm,incomplete eyelid closure and other abnormal eyelids;

(3) In recent 3 months,there were patients who received eye anti Demodex treatment or used glucocorticoids and antibiotics.

2.5 Research method

30 cases (60 eyes) in the experimental group were treated with traditional Chinese medicine ultrasonic atomization combined with meibomian gland massage,and 30 cases (60 eyes) in the control group were treated with meibomian gland massage.Composition of traditional Chinese medicine:Sophora flavescens,Scutellaria baicalensis,Fangfeng,mint,chrysanthemum,etc.(the prepared pieces and preparation process of medicinal materials are provided by the preparation room of China Japan Friendship Hospital).The above traditional Chinese medicine is made into 100ml Decoction and stored in the refrigerator.Before use,heat the packaged traditional Chinese medicine decoction with warm water to 40～50oc.Specific atomization method:inject 20ml Decoction into the atomizer container,aim the nozzle at the patient's eyes,and ask the patient's eyes to receive treatment alternately for 20 minutes.The frequency of ultrasonic atomization of traditional Chinese medicine is 1 time/ day,and 7 days is a course of treatment.All patients completed 2 courses of treatment.Meibomian gland massage treatment,all patients once a week for 2 weeks.Massage method of meibomian gland:in the supine position,drop obukaine hydrochloride eye drops into the conjunctival sac for surface anesthesia,turn over the upper and lower eyelids in turn,press from the fornix to the meibomian gland opening with a glass rod along the direction of meibomian gland tube,and finally wipe the eyelid margin with a cotton swab.

2.6 Observation index and inspection method

At baseline and 2 weeks after treatment,all enrolled patients were given eye Demodex count,symptom score,but,sit,meibomian gland secretion function score,meibomian gland secretion character score,etc.

2.6.1 Specific operation

For eye Demodex count,the modified Coston method is used to extract eyelashes [10].Use sterile micro tweezers to vertically lift eyelashes,rotate 45o clockwise for 3～ 4 circles,and then remove eyelashes.Remove 3 eyelashes from each eye's upper and lower eyelids respectively.There are 12 eyelashes in both eyes.The removed eyelashes are immediately placed on the slide and covered with a cover glass,Observe and count under an ordinary optical microscope (as shown in Figure 1).

Figure 1 Count of demodex ocular mite under optical microscope

2.6.2 The symptom score was scored by questionnaire,including the following clinical symptoms

(1) Dry feeling(2) Foreign body sensation(3) Burning sensation(4)Itching(5) Photophobia(6) Red eyes(7) Eye pain(8) Eyelash secretion in the morning(9) Tears(10) Blurred vision(11) Visual acuity fluctuation(12) Eye fatigue(13) Reading(14) Driving at night(15) Operate the computer(16) Watch TV(17) Windward(18) Dry or air-conditioned places(19) Environmental sanitation.In the past week,0 points were given for asymptomatic symptoms,1 point for mild symptoms,2 points for moderate symptoms,3 points for severe symptoms,and 4 points for very serious symptoms,totaling 0-76 points.

2.6.3 Tear film break-up time (BUT) and tear secretion test(SIT) refer to the detection methods in ophthalmology[9]

But after wetting the sodium fluorescein test paper with 0.9%normal saline,smear the lower eyelid conjunctival sac,ask the patient to blink for 5 times and look straight ahead.The measurer observes the time from the patient's eyes opening after the last blink to the first black spot on the cornea under the cobalt blue light of slit lamp microscope,repeat the measurement for three times and take the average value.

Schirmer I test without surface anesthesia.Fold the 5mm scale of the tear detection filter paper and put it in the conjunctival sac of the patient's lower eyelid from the middle to the outside.After 5min,remove the filter paper and read the scale value.

2.6.4 meibomian gland secretory function score[1]

Observe 15 glands on the upper eyelid (5 on the nasal side,middle side and temporal side respectively),and all 5 glands secrete 0 point;1 point for secretion of 3～ 4 glands;Secretion of 1～ 2 glands:2 points;No gland secretion,3 points.

2.6.5 Character score of meibomian gland secretion[1]

0 point for clear and transparent secretion;Secretion turbidimeter 1 point;2 points for turbid and granular secretions:3 points for thick secretions like toothpaste.

2.7 Statistical method

Statistical analysis:all data were analyzed by statistical software spss25.0,and the measurement data were tested for normality.But,sit and symptom scores were in line with normal distribution,expressed as mean ± standard deviation (x ± s).Paired t-test was used for comparison before and after treatment in the same group,and independent sample t-test was used for comparison between groups.The meibomian gland secretion function score,meibomian gland secretion character score and the number of ocular Demodex did not meet the normal distribution,expressed in the median(interquartile spacing) m (P25,p75).The Wilcoxon signed rank test was used for the comparison before and after treatment in the same group,and the Mann Whitney U test was used for the comparison between groups.The difference was statistically significant (P<0.05).

3.Results

3.1 Comparison of tear film rupture time (but) in group

There was no significant difference in but between the experimental group and the control group before and after treatment (P>0.05).There was no significant difference in but between the experimental group and the control group before and after self-treatment (P>0.05).

Table 1 Comparison of BUT between 2 groups before and after treatment(s,)

Table 1 Comparison of BUT between 2 groups before and after treatment(s,)

3.2 Comparison of tear secretion test (SIT) between the two groups

There was no significant difference in sit between the experimental group and the control group before and after treatment (P>0.05).There was no significant difference in sit between the experimental group and the control group before and after self-treatment (P>0.05).

Table 2 Comparison of SIT between 2 groups before and after treatment(mm,)

Table 2 Comparison of SIT between 2 groups before and after treatment(mm,)

3.3 Comparison of symptom scores between the two groups

There was no significant difference between the baseline value of symptom score between the experimental group and the control group (P>0.05).There was significant difference between the two groups after treatment (t=-7.022,P<0.01).There was significant difference in symptom scores before and after treatment in the experimental group (t=10.394,P<0.01),but there was no significant difference in symptom scores before and after treatment in the control group (P>0.05).

Table 3 Comparison of symptom scores between 2 groups before and after treatment(score,)

Table 3 Comparison of symptom scores between 2 groups before and after treatment(score,)

Note:* compared with that before treatment,P <0.05# Compared with the control group after treatment,P <0.05.

3.4 Comparison of secretory function scores of meibomian gland between the two groups

There was no significant difference in the baseline value of meibomian gland secretion function score between the experimental group and the control group (P>0.05).There was significant difference in meibomian gland secretion function score between the two groups after treatment (z=-4.704,P<0.01).There was significant difference in the score of meibomian gland secretion function before and after treatment in the experimental group (z=-4.116,P<0.01),but there was no significant difference in the score of meibomian gland secretion function before and after treatment in the control group (P>0.05).

Table 4 Comparison of meibomian gland secretion function scores between 2 groups before and after treatment(score,M(P25,P75))

3.5 Comparison of character scores of meibomian gland secretion between the two groups

There was no significant difference in the baseline score of meibomian gland secretion between the experimental group and the control group (P>0.05).There was no significant difference in the score of meibomian gland secretion between the two groups after treatment (P>0.05).There was significant difference in the character score of meibomian gland secretion before and after treatment in the experimental group (z=-2.495,P <0.01),but there was no significant difference in the character score of meibomian gland secretion before and after treatment in the control group (P>0.05).

Table 5 Comparison of eyelid fat traits scores between 2 groups before and after treatment(score,M(P25,P75))

3.6 Comparison of the number of ocular Demodex between the two groups

There was no significant difference in the baseline value of the number of ocular Demodex between the test group and the control group (P>0.05).There was significant difference in the number of ocular Demodex between the two groups after treatment (z=-4.704,P<0.01).There was significant difference in the number of ocular Demodex before and after treatment in the experimental group (z=-4.524,P<0.01),but there was no significant difference in the number of ocular Demodex before and after treatment in the control group (P>0.05).

Table 6 Comparison of Demodex count between 2 groups before and after treatment(M(P25,P75))

3.7 Safety observation

No adverse reactions occurred during the treatment.

4.Discussion

Meibomian gland dysfunction is the main cause of lipid abnormal dry eye and the main cause of eye discomfort in patients with dry eye [11].Epidemiological investigation results show that the incidence rate of MGD in China is 68% to 69.3%[12].Many ocular and systemic factors can lead to MGD,and demodex infection may be one of the important factors causing MGD [2].At present,the research on the pathogenesis of ocular demodex infection mainly includes three aspects:the physical and chemical damage caused by Demodex to the ocular surface,as a carrier of microorganisms and causing immune response and inflammatory response [13].The cortical Demodex parasitic on the meibomian gland not only mechanically blocks the meibomian gland duct and meibomian gland opening,but also stimulates the surrounding tissue to form chronic granuloma [14].Mechanical stimulation and repeated inflammatory reaction can cause the opening keratosis of meibomian gland,increase the resistance of lipid transport in gland tube,and disorder the function of meibomian gland.With the further development of the disease,the glandular duct of meibomian gland may expand,which may eventually lead to the obstruction of palpebral ester production and excretion,and the change of tear film lipid layer [15].

MGD belongs to the category of white astringent disease,eyelid string red rot and other diseases in traditional Chinese medicine[16].The etiology and pathogenesis of MGD in traditional Chinese medicine are still inconclusive.Now it is mostly considered that it is caused by exogenous wind,dampness and heat evil,internal injury to the spleen and stomach,accumulation of phlegm and dampness,upper invasion of the eyelid,rheumatism and heat evil,beating on the eyelid edge for a long time,blocking the Qi machine,resulting in poor operation of Qi and blood and loss of nourishment [17].The early studies on the inhibition and killing of eye Demodex by traditional Chinese medicine were mainly in vitro experiments.Huang Lijuan et al.[18] extracted 30 effective components of traditional Chinese medicine by 80% ethanol thermal reflux method.It was found that traditional Chinese medicine such as clove,Xanthium sibiricum,dandelion,wormwood leaf,Sophora flavescens,Stemona,mint and so on had a good effect on killing eye Demodex in vitro.At present,there are few clinical observations and studies on the treatment of Demodex related eye diseases with traditional Chinese medicine at home and abroad.In the traditional Chinese medicine compound selected in this study,Sophora flavescens clearing heat and dampness,killing insects and relieving itching;Scutellaria baicalensis can clear away heat,dry dampness,purge fire and detoxify;Windproof,wind dispelling and dehumidification;Peppermint expels wind and heat,clearing and benefiting the leader;Chrysanthemums disperse wind heat,calm the liver and brighten the eyes.The combination of various drugs can dispel wind,clear away heat,remove dampness and relieve itching.In this study,traditional Chinese medicine is directly applied to the lesion in the form of ultrasonic atomization to promote the drug force to reach the affected area.On the other hand,it can also promote the local blood circulation of eyelid and enhance the penetration ability of drug effect,so as to give full play to the drug effect [19] Compendium of Materia Medica [20]:"the bitter and cold of Sophora flavescens can tonify the kidney,cover its bitter,dry and wet,and eliminate heat.Heat generates wind and dampness generates insects,so it can cure wind and kill insects ".Relevant modern pharmacological studies show that the alkaloids contained in Sophora flavescens can resist bacteria and inflammation,and show antibacterial efficacy against Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa,Proteus and other pathogenic bacteria[21].In addition,in vitro experiments showed that Sophora flavescens had good anti Demodex activity[22].Demodex is the carrier of some microorganisms.They both participate in the pathogenesis of Demodex related diseases.The anti-inflammatory,anti microbial and anti Demodex effects of Sophora flavescens are beneficial to the treatment of Demodex related eye diseases.However,the anti Demodex activity of Sophora flavescens has not been confirmed by clinical trials.In the future,the in-depth study of its anti mite activity will help to solve the treatment problems of Demodex related eye diseases.

The observation results of this study show that traditional Chinese medicine ultrasonic atomization treatment can alleviate the clinical symptoms of patients with meibomian gland dysfunction complicated with demodex infection,improve the secretion function and secretion properties of meibomian gland,reduce the number of ocular Demodex to a certain extent,and has good safety.We believe that traditional Chinese medicine may achieve clinical therapeutic effect by improving the secretory function of meibomian gland and inhibiting the survival of ocular Demodex.There was no significant difference in but score and sit score before and after treatment,which may be related to the short observation cycle of the study.

Author's contribution:Hou Xiaoyu and Qin Yali are responsible for patient diagnosis,data collection,article data sorting,statistics and article writing;Jin Ming is responsible for the treatment of patients before and after treatment and the revision of articles;Deng Tingting:responsible for the overall planning of articles and data review.