A Randomized Controlled Trial of Auricular Acupressure Combined with Sodium Hyaluronate for Abnormal Blink Reflex in Children

Summary

Auricular acupressure combined with sodium hyaluronate significantly improved blink rate, tear film stability, and ocular symptoms in children with abnormal blink reflex, suggesting a safe and effective complementary therapeutic approach.

Abstract

Abnormal blink reflex in children is a common ocular symptom with complex causes, including ocular surface diseases like dry eye and inflammation, as well as neuromuscular dysfunction. Current treatments show limited efficacy, highlighting the need for improved therapeutic options. This study evaluates the clinical efficacy and safety of auricular acupressure combined with sodium hyaluronate eye drops. A randomized controlled design included 97 children aged 3–10 years with abnormal blink reflex. Participants were randomly assigned to three groups: the control group (Group A, n = 32), treated with sodium hyaluronate eye drops; the experimental group (Group B, n = 33), receiving eye drops combined with auricular acupressure using Vaccaria seed patches; and the sham stimulation group (Group C, n = 32), receiving ear patches without Vaccaria seed. The treatment lasted for three cycles. The primary outcome was the blink rate, and secondary outcomes included tear film break-up time (FBUT), corneal fluorescein staining (FL) score, Visual Analog Scale (VAS) scores for ocular dryness and photophobia, clinical efficacy, and adverse events. Compared with Groups A and C, Group B showed a significant reduction in blink rate (P<0.05), a significant increase in FBUT (P<0.05), a notable decrease in FL score (P<0.05), and a significant reduction in VAS scores for ocular dryness and photophobia (P<0.05). No statistical differences in clinical symptoms and signs were observed between Groups A and C (P>0.05). The total effective rate was 78.13% for Group A, 93.94% for Group B, and 84.38% for Group C, with Group B showing significantly higher efficacy. No serious adverse events were observed in any group. Auricular acupressure with Vaccaria seed improves the clinical symptoms of abnormal blink reflex in children, enhances tear film stability, and provides corneal protection. It is a safe and effective new intervention for the treatment of abnormal blink reflex in children.

Introduction

Blinking is a normal motor activity of the eyes that may occur spontaneously, voluntarily, or as a reflex. Typically, the blink rate is about 10 to 15 times per min¹. Blinking helps spread tears across the surface of the eyeball and aids in the secretion of glands in the eyelids, prolonging the duration of tear film on the ocular surface. The blink rate and blink interval are influenced by the characteristics of the ocular surface². Abnormal blinking is generally defined as blinking frequency and/or force beyond the normal physiological range. Abnormal blinking in children is a common symptom in ophthalmology³. Its main causes include eyelid disorders, habitual eye muscle twitching, uncorrected refractive errors, intermittent strabismus, and neurogenic blepharospasm, and other neurological conditions such as trigeminal neuralgia and facial nerve paralysis^3,4,5,6,7,8. A previous study shows that 6% of patients under the age of 16 have vision-threatening diseases, which are often easily detected during standard clinical examinations⁹. Therefore, a comprehensive evaluation of the causes of abnormal blinking in children and early intervention is crucial for preventing visual impairment and improving quality of life.

In clinical practice, for children with excessive blinking, the primary task is to differentiate between benign, reversible factors (such as dry eye, ocular surface inflammation, or environmental irritants) and neuropsychiatric causes (such as tic disorders). In most cases of excessive blinking in children, medication is not required. The first step is to identify triggers (such as fatigue, stress, allergies, and ocular surface irritation) and provide symptomatic treatment¹⁰. Warm compresses (WC) have been shown to decrease partial blink frequency (PBF) and partial blink rate (PBR) (p = 0.002 in both cases)¹¹. Although the efficacy of WC has been confirmed in various studies, poor compliance due to the required time and temperature cannot be overlooked¹². 0.1%–0.4% hyaluronic acid artificial tears can significantly improve signs and symptoms of dry eye and are suitable for children with excessive blinking associated with dry eye and ocular surface irritation¹³. For blinking related to tic disorders, comprehensive behavioral interventions (CBIT, based on Habit Reversal Training, HRT) have a reliable evidence base; several randomized controlled trials and comparative studies have shown that CBIT significantly reduces tic severity and improves daily functioning, with a low risk of adverse effects. The CDC has also listed CBIT as an effective behavioral treatment option¹⁴. Although existing interventions can improve symptoms of excessive blinking in children to some extent, issues such as poor compliance, varying efficacy, and lack of individualized treatment strategies remain. Therefore, further exploration of the mechanisms and evidence-based treatments for excessive blinking is important for optimizing clinical management and improving long-term outcomes for children.

In recent years, traditional Chinese medicine therapies have shown promising efficacy in treating abnormal blinking in children. For example, Muzha Formula has been used to treat frequent bilateral blinking for three weeks, with no recurrence observed after one year¹⁵. A study by Dong Wu et al.¹⁶ demonstrated that laser acupuncture can improve the blink reflex. Acupuncture treatment in two children with frequent blinking resulted in complete resolution of symptoms, with no recurrence after one year of follow-up¹⁷. Auricular acupressure using Vaccaria segetalis seeds is an emerging traditional Chinese medicine therapy¹⁸. Auricular acupressure using Vaccaria segetalis seeds is a traditional Chinese medicine-based, noninvasive therapy. Vaccaria seeds are natural botanical seeds attached to specific auricular acupoints with adhesive tape to provide prolonged mechanical stimulation. Auricular therapy involves stimulating specific points on the external ear and, according to traditional Chinese medicine theory, is believed to regulate qi and meridian function. In the 1950s, Paul Nogier proposed the “inverted fetus map” theory, which contributed to the foundation of modern auricular therapy¹⁹. Vaccaria seeds are applied to auricular points to provide continuous, non-invasive stimulation, potentially improving ocular function and alleviating blinking. Based on these findings, this study aims to evaluate the clinical efficacy and safety of auricular acupressure combined with sodium hyaluronate eye drops for treating abnormal blinking in children with dry eye. This study seeks to provide a more optimized and effective treatment option for clinical management of this condition.

Protocol

This study was registered as a randomized controlled clinical trial on the International Traditional Medicine Clinical Trial Registration Platform (No: ITMCTR2025001972). The study was conducted at the Ophthalmology Outpatient Department of the Affiliated Hospital of Changchun University of Traditional Chinese Medicine, in accordance with the ethical principles outlined in the Declaration of Helsinki and Good Clinical Practice (GCP). Ethical approval was obtained from the hospital's Medical Ethics Committee (No: CCZYFYLLSQ2025039). Written informed consent was obtained from the parents of all participants prior to participation in the study.

Patient Recruitment

This randomized controlled trial was designed to assess the therapeutic effect of auricular acupressure using Vaccaria seeds in children with abnormal blinking classified as the Spleen Deficiency and Liver Excess type. Participants were recruited from the ophthalmology outpatient clinic at the Affiliated Hospital of Changchun University of Traditional Chinese Medicine from April to December 2025 through hospital publicity and electronic posters. Figure 1 shows the experimental setup and participant recruitment process. The inclusion criteria were: (1) subjective symptoms of blinking with a blink frequency >15 times/min; (2) no associated facial muscle spasms or other systemic diseases; (3) relatively independent clinical symptoms, with no neurological diseases; (4) primary cause identified as dry eye; (5) consent to participate in the study and sign an informed consent form.

The exclusion criteria included: (1) alternating blinking or other symptoms related to movement disorders; (2) severe heart, liver, kidney, or ocular organic diseases; (3) severe psychiatric disorders or communication barriers; (4) allergies to any components of the study intervention; (5) recent history of other interventions or surgeries.

Baseline Examination

Sample Size Calculation

Sample size calculation software was used to estimate the required sample size based on the expected difference in blink rate before and after treatment, with the significance level (α) set at 0.05 and the statistical power (1−β) set at 0.80. The calculated sample size was 30 participants per group. Considering a 20% dropout rate, the final sample size was set at 36 participants per group, resulting in a total sample size of 108 participants across the three groups²⁰.

Randomization and Allocation Concealment

Participants were randomly assigned to Group A, Group B, or Group C in a 1:1:1 ratio using block randomization with a block size of 6. The randomization sequence was generated using statistical software (version 4.0.3) with the “blockrand” package. To ensure allocation concealment, the intervention materials, including the Vaccaria seed auricular acupressure patches and control ear patches, were prepared and coded by an independent researcher who was not involved in participant recruitment, treatment administration, or outcome assessment. Each intervention package was labeled with a unique code corresponding to the randomization sequence, sealed, and distributed sequentially according to participant enrollment order.

Blinding

Participants, their parents or caregivers, treatment providers, and outcome assessors were blinded to group allocation throughout the trial. Subjective outcomes, particularly the visual analog scale (VAS) scores for ocular dryness and photophobia, were assessed by blinded evaluators. When caregiver assistance was required, caregivers were instructed to report symptoms without knowledge of the treatment assignment to minimize potential assessment bias. The blinding process was maintained throughout the study to ensure unbiased evaluation while preserving the comfort and cooperation of the children.

Intervention Procedure

Participants were randomly assigned to one of three groups: Group A received sodium hyaluronate eye drops; Group B received sodium hyaluronate eye drops combined with Vaccaria segetalis seed auricular acupressure patches; and Group C received sodium hyaluronate eye drops combined with sham ear patches.

All participants received treatment for 3 cycles, each lasting 5 days, for a total intervention period of 15 days. Sodium hyaluronate eye drops were administered as 1 drop, 3 times daily. Participants and caregivers were instructed to ensure hand hygiene before administration. During the intervention, participants were monitored for skin irritation, allergic reactions, or discomfort at the auricular patch site. The intervention was discontinued if any adverse reaction occurred.

For participants in Group B, the auricle was disinfected with medical alcohol before patch application. Auricular acupressure patches containing Vaccaria seeds were applied to the following auricular acupoints: eye, brainstem, liver yang, subcortical, liver, spleen, endocrine, and sympathetic. The acupoint locations were identified according to the standardized auricular acupoint atlas used in traditional Chinese medicine. Each patch was firmly attached to the selected acupoint, and gentle pressure was applied with the thumb and index finger until the participant reported a sensation of soreness or distension. Each acupoint was pressed for approximately 1 minute, with a total stimulation time of about 8 minutes per session.

Each 5-day cycle consisted of 4 days of patch application followed by a 1-day rest period. During the 4-day application period, the patches were replaced every other day. To ensure consistency, all auricular acupressure procedures were performed by the same trained practitioner using a standardized protocol.

Follow-up Evaluation

Outcome assessments were performed at baseline, at the end of each treatment cycle, and after completion of the final treatment cycle.

4.1 Primary Outcome Measures

Blink Rate

Conduct assessments in a quiet, undisturbed environment. Observe the child's blink rate during natural conversation with the examiner. Blink rate was manually counted by the examiner during natural conversation with the child in a quiet and undisturbed environment. Each observation lasted 1 min, and the blink rate was recorded three consecutive times. The average value of the three recordings was calculated and used for analysis. Categorize the blink rate into four levels of efficacy. Cure was defined as a blink rate ≤15 blinks/min after treatment. For participants whose blink rate remained >15 blinks/min, treatment efficacy was evaluated based on the percentage reduction from baseline: marked improvement (51%–75% decrease), effective (25%–50% decrease), and ineffective (no significant improvement). The total effective rate was calculated as (Cure + Marked Improvement + Effective cases) / Total cases x 100%.

Secondary Outcome Measures

Fluorescein Staining Tear Film Break-Up Time (FBUT)

Moisten fluorescein sodium test strips with 0.9% saline and apply them to the inferior conjunctival sac of the child’s lower eyelid under sterile conditions. Observe the first black spot that appears on the cornea during the last blink under cobalt blue light. Repeat this process three times and calculate the average time. Ensure the FBUT value is normal (10–45 s)²¹. Record a tear film break-up time of <10 s as indicating instability.

Corneal Fluorescein Sodium Staining Score (FL)

Observe the corneal epithelial staining under cobalt blue light. Score the staining degree (0 for negative, 1 for punctate, 2 for localized patchy, and 3 for confluent block). Evaluate in four quadrants (superior nasal, inferior nasal, superior temporal, and inferior temporal). Sum the scores from each quadrant to get the total score (ranging from 0 to 12)²².

VAS Scores for Ocular Dryness and Photophobia

Visual Analog Scale (VAS) scores were used to evaluate ocular dryness and photophobia. A 10-cm horizontal line was presented to the participant, with the left end labeled “no symptoms” (score = 0) and the right end labeled “worst imaginable symptoms” (score = 10). The child, with assistance from a caregiver when necessary, was asked to mark a point on the line that best represented the severity of their symptoms at the time of assessment. The distance from the left endpoint to the marked point was measured and recorded as the VAS score. For younger children who had difficulty completing the scale independently, the caregiver assisted in reporting the symptoms under the guidance of the investigator. The VAS method is widely used for assessing subjective symptoms such as ocular discomfort and has demonstrated good reliability and validity in clinical research²³.

Safety Indicators

Monitor safety throughout the trial. Record any signs of drug allergies or discomfort before and after treatment. Assess adverse events during treatment and follow-up, such as rash, local irritation, or other symptoms. Calculate the incidence of adverse events as (number of adverse events / total cases) x 100%. Monitor serious adverse events (loss of function, disability, or life-threatening conditions) and calculate the incidence as (number of serious adverse events / total cases) × 100%.

Data Analysis

Organize and analyze data using statistical analysis software. For normally distributed data, use mean ± standard deviation (X ± s). For non-normal data, use the median and interquartile range [M (P25, P75)]. Perform inter-group comparisons using one-way analysis of variance (ANOVA). Express data as frequency or percentage. Use the chi-square test for inter-group comparisons. Set p-value < 0.05 as statistically significant. Create statistical graphs using GraphPad Prism 10 software.

DATA AVAILABILITY:

The datasets used and analyzed during the current study are available at https://doi.org/10.6084/m9.figshare.31866238

Results

Baseline Characteristics

A total of 108 children with abnormal blinking were enrolled. Four participants discontinued due to failure to complete consecutive treatments, three did not follow the prescribed auricular acupressure regimen, three voluntarily withdrew, and one was terminated due to concomitant allergic conjunctivitis. As a result, 97 participants completed the study (Group A: n = 32; Group B: n = 33; Group C: n = 32).

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Discussion

This study, using a randomized controlled design, evaluated the efficacy of auricular acupressure with Vaccaria seed combined with sodium hyaluronate eye drops in the treatment of abnormal blinking in children. The results showed that auricular acupressure with Vaccaria seed significantly reduced the blink rate, prolonged tear FBUT, improved corneal FL scores, alleviated clinical symptoms of ocular dryness and photophobia, and increased the total effective rate. These findings suggest that this interven...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Fluorescein Sodium Test Strips	Tianjin Jingming New Technology Development Co., Ltd.	Medical Device Registration No.: 20222160497	Used for corneal injury assessment and tear film stability testing
GraphPad Prism 10	GraphPad Software, San Diego, CA, USA	N/A	Used for generating statistical charts
IBM SPSS Statistics 27	IBM Corp., Armonk, NY, USA	N/A	Used for data processing and analysis
PASS 21.0	NCSS, LLC, Kaysville, Utah, USA	N/A	Used for sample size estimation
Sodium Hyaluronate Eye Drops	Santen Pharmaceutical (China) Co., Ltd.	National Drug Approval Number: H20173248	Administer 1 drop, 3 times per day
Vaccaria Seed Auricular Acupressure Patches / Ear Acupressure Patches	Shanghai Taicheng Technology Development Co., Ltd.	Model No.: E-S	Complete each session in 1 minute, totaling 5 minutes per session. Apply the patches for 4 days without changing. Reapply patches every other day, without further changes.