Methodological quality of the review: Medium confidence
Author: Haixia Gao, Lei Zhang, Jianghong Liu
Region: China and Taiwan
Subsector: Auricular acupressure for myopia treatment
Equity focus: No
Study population: Children and adolescents
Type of programme: Community based
Review type: Other review
Quantitative synthesis method: Systematic review
Qualitative synthesis method: Not applicable
Background: Myopia is a condition in which visual images come into focus in front of the retina of the eye, rather than on the retina itself as in normal vision, resulting in a blurred view of distant objects. Myopia has emerged as a global public health concern. It tends to lead to additional vision difficulties for those affected by the disorder, especially for children and young adults. In 2010, uncorrected refractive error was estimated to be the most common cause of distance vision impairment and the second most common cause of blindness worldwide. Given the rapidly increasing prevalence of myopia in children and young adults, its profound impact on vision health, and the economic burden on family and society, there is a pressing need for interventions to help eliminate myopia or slow its progression in children and young adults. Unlike these current treatment methods, auricular acupressure has been described as an easy, non-invasive, and low-cost technique to mitigate the progression of myopia. It is difficult for clinicians and researchers to determine precisely whether treatment effects could be ascribed to auricular acupoint pressure alone, to a combination of auricular acupoint pressure and other methods, or to other therapies alone. Now, new randomised-controlled trials evaluating the effect of auricular acupressure on myopia are available.
Objectives: To identify and assess the evidence showing the efficacy of auricular acupressure alone for myopia in children and adolescents.
Main findings: 10 RCTs were included to be qualitatively summarised, of which five studies with a total of 724 participants (1,145 eyes) qualified for the meta-analysis. Only two studies (20%) had clearly reported random sequence generation by computer or a table of random numbers. Most of the studies (80%) did not report either the method of allocation concealment or the method of blinding caregivers and personnel. However, nine studies (90%) displayed a low risk of bias at blinding of outcome assessment. All 10 studies (100%) provided acceptable incomplete outcome data and important outcomes, thus, they can be considered as at a low risk of bias from either incomplete outcome data or selective outcome reporting. Eight studies were published in Chinese, and two in English. All participants of the 10 studies were aged from 5 to 18. For the control group, eyedrops were used in five studies, acupuncture was used in two studies, eye exercise was used in one study, and no treatment was used in two studies. Regarding the auricular acupressure intervention, participants were instructed to self-administer acupressure in nine studies, while the professional oculist gave children auricular pressure treatment in one study. All studies had standardised selection of 2-13 acupoints. All of the studies included the LO5 (Eye) and CO12 (liver) acupoints, nine studies included the CO10 (kidney) acupoint, seven studies included the TG2b (anterior intertragal notch), AT1b (posterior intertragal notch) and TF4 (Shenmen) acupoints. Eight studies reported the strength of acupressure whenever participants experienced mild acid, numbness, swelling and pain, whereas two studies had not reported it. The meta-analysis of five trials showed superior effects of auricular acupressure on the efficacy rate in improving visual acuity for myopic children and adolescents when compared with using eyedrops (Chi2=48.14, P<0.00001, I2=92%) (Fig. 3). One study demonstrated that the efficacy rate in improving visual acuity was found to be significantly higher in the auricular acupressure group when compared to the eye exercise group (86.15% versus 60.61%, P<0.01). A study reported that children aged 8 to 9 years who received auricular acupressure for three months had a significant improvement in binocular naked vision in comparison with children undergoing examination of visual function every other day for three months (0.71 ± 0.15 versus 0.61 ±0.15; P=0.003). Similarly, the Chen et al. study found that myopic children treated by auricular acupressure showed visual acuity improvement in contrast with no treatment. Two RCTs examined the effect of auricular acupressure on refractive error of myopic children and adolescents. In the Zheng study, although the post-intervention mean diopter was not significantly different between the auricular acupressure group and the acupuncture group (-1.02 ± 0.614 versus -1.02 ± 0.533, P>0.05), there were significant differences in refractive error before and after intervention for the two groups, respectively (auricular acupressure group: pre -1.47 ± 0.521, post -1.02±0.614, P<0.01; acupuncture group: pre -1.46±0.469, post -1.02± 0.533; P<0.01. In another trial, Chen et al. reported the effects of auricular acupressure in improving children’s refractive error compared with no intervention (auricular acupressure group: 1.98 ±2.04 versus -2.98 ±1.94; P=0.04). No study reported whether or not any adverse events occurred in auricular acupressure.
Authors conclude that auricular acupressure could slow the progression of myopia in children and adolescents. However, there is a need for further studies with higher methodological quality and sufficient follow-up.
The inclusion criteria followed the PICO format: P (population): We included studies in which participants were younger than 18 years old and were diagnosed with myopia using cycloplegic refraction or an age-appropriate vision test for confirmation. Additionally, participants did not have ocular pathology by external and internal eye examination. I (intervention): Only those trials in which auricular acupressure alone was applied to treat myopia were included, regardless of what ear acupoint, manual pressing mode, frequency, duration, or taped object was used. C (comparison): To capture a general trend, trials in which auricular acupressure was compared with any alternative interventions, such as blank control (no treatment)/sham auricular acupressure/drugs/surgery/acupuncture, massage, and so on were used.
O (outcome): The following outcomes were used to evaluate the efficacy and safety of auricular acupressure for treating myopia: efficacy rate in improving visual acuity, mean visual acuity, mean refractive error, mean change in axial length, mean change in corneal radius of curvature, and adverse outcomes, such as pain, psychological distress, infection, bleeding or vomiting, etc.
This systematic review was conducted following the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions, and results were reported according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) [24,25]. Searches were conducted for all articles, from inception to March 2019, in databases including PubMed, Web of Science, OVID, FMRS (Foreign Medical Literature Retrieval Service), China Knowledge Resource Integrated Database (CNKI), The Chinese Biological Medicine Database (CBM), Wanfang Database and Chongqing VIP Information. English search terms included (nearsightedness OR myopia OR refractive error OR visual acuity OR short-sightedness OR dioptres OR myopia prevention OR nearsightedness OR near sight OR short-sight) and (auricular acupressure OR auricular acupoints OR auricular application pressure OR auricular-point-pressing therapy OR ear acupressure OR auricular pressing OR auricular pressure). The search was also conducted in Chinese. The first two authors independently reviewed titles and abstracts, and selected the relevant articles. The quality of RCTs was assessed by the first two authors using the Cochrane Risk of Bias assessment tool. Data was independently extracted from all included studies using a standardised extraction form by two reviewers (the first two authors), which included publication year and country, author information, participants’ characteristics (age, sex, course of myopia), intervention characteristics (for example, ear acupoints, manual pressing mode, frequency and duration of auricular acupressure, taped objects) and outcomes (including outcome measures and the result).
Applicability/external validity: For the external applicability of this review, the authors mention that the results and conclusions of this systematic review should be treated carefully, because of some limitations which undermine the strength of the review. The authors reported language restriction: Japanese and Korean papers were excluded which may cause publication bias. Evidence on the efficacy of auricular acupressure for myopia in children and adolescents was low. The quality of included trials was generally moderate, or even poor, with considerable heterogenicity.
Geographic focus: Not discussed.
Summary of quality assessment:
In conclusion, this review was attributed medium confidence. Despite the rigorous methodology, some details on data analysis were lacking. Moreover, the authors reported language restrictions, where Japanese and Korean papers were excluded, increasing the risk of language and publication bias. In addition, authors did not conduct a thorough search of the literature to ensure that all relevant studies were included, which could impact on the reliability of findings.
Few studies were included, reducing the evidence on the efficacy of auricular acupressure for myopia in children and adolescents. The quality of included trials was moderate and heterogenicity was poor.