The content followed preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P)
2.1. Eligibility criteria
2.1.1. Types of studies. This review will include all randomized controlled trials (RCTs) in English or Chinese and without the restriction of publication type. Non-RCTs, quasi-RCTs, uncontrolled trials, case series, case reports, crossover studies, letters, and laboratory studies will be excluded.
2.1.2. Types of participants. Patients with ONP were diagnosed according to the book named Neurology[16]. Information relating to their age, sex, race, education, nationality, or economic status is not taken into account.
2.1.3. Types of interventions
2.1.3.1 Experimental interventions. The forms of acupuncture therapy include body acupuncture, electro-acupuncture, auricular acupuncture, intradermal needle, scalp acupuncture, ocular acupuncture, fire needling, elongated needling, and plum blossom needle. Acupoint injection, laser acupuncture, moxibustion, cupping, and acupressure will be excluded.
2.1.3.2. Control interventions. Types of control interventions include placebo control, sham acupuncture (use acupuncture needle to insert into skin without penetrating exact acupoints), western medicine compare with acupuncture, drug therapy, other therapies, no therapy and acupuncture plus 1 treatment compares with the same treatment.
2.1.4. Types of outcome measures
2.1.4.1. Primary outcomes. The primary outcome included:
(1) Scores of diplopia: visual analog scale (VAS)[11,17]
(2) Palpebral fissure size: from midpoint of upper eyelid to midpoint of lower eyelid.[13,15,18]
(3) Therapeutic efficiency: refer to the State Administration of Traditional Chinese Medicine issued the Standard for the Diagnosis and Curative Effect of Disease and Syndromes of Traditional Chinese Medicine[18-19].
(4) The range of eye movement: the distance from the lateral canthus to the center of the pupil was taken as the datum and the distance between the two maximal activity points was recorded[18].
(5) Measure pupil diameter: measure pupil size under light[17].
2.1.4.2. Secondary outcomes. The secondary outcome included:
(1) Measure the patients’ quality of life: quality of life assessment scale SF-36(short form 36 questionnaires)[5]
(2) Adverse effects
2.2. Search strategy
To evaluate the efficacy and safety of acupuncture for ONP, the following databases will be searched: PubMed, Cochrane Library, Medline, Chinese Biomedical Literature Database, China National Knowledge Infrastructure (CNKI), Wanfang data, Chinese Scientific Journal Database. In addition, relevant references and RCTs cited in the reports will be researched as supplementary sources. We will also study the gray literature.
The search strategy for PubMed is detailed in Table 1.It will also be used for any other electronic databases.
Table 1. Search strategy used in PubMed databases
2.3. Data collection and analysis
2.3.1. Selection of studies. All reviewers will get trained to understand the aim and process of the system review and will select the trials and studies separately. Two reviewers will screen the titles, abstracts and keywords based on the inclusion criteria and the full text will be read for further assessment if necessary. Details of the research choices are shown and exclusive studies will be listed and explained. The process of study selection will be presented in PRISMA flow diagram (Fig.1)
2.3.2 .Data extraction and management. Three viewers (XHZ, SMZ and RSD) will independently extract the data from the studies and fill in the data collection form. The discrepancies and uncertainties in the process will be discussed and solved with a senior reviewer HC. We will contact the corresponding authors for more information if the details of trials were not completed. All data will be transferred into review manager software. We will extract information such as author, time of publication, participants information (age, sex), sample size, interventions, outcome indicators, and other details.
2.3.3. Risk of bias assessment. We will use Cochrane risk of bias assessment tools to evaluate 6 domains of bias(sequence generation, allocation concealment, blinding, incomplete outcome data, selective outcome reporting ,and other sources of bias ).The included studies will be divided into 3 parts: unclear , low risk, and high risk. The discrepancies will be solved with a senior reviewer called HC.
2.3.4. Assessment of heterogeneity. I square (I2) statistic will be used to assess heterogeneity in included studies, which describes the percentage of variation between studies due to heterogeneity. If I2<50%, we will choose the fixed-effect model to calculate risk ratio (RR) and mean difference(MD), otherwise use a random-effect model.
2.3.5. Measures of treatment effect. We used review manager 5.3 for meta-analysis to analyze data. We will use MD or standardized mean difference with 95% confidence interval(CI) to synthesize continuous variables. For dichotomous data, we will use the RR with 95% CI.
2.3.6. Dealing with missing data. We will contact the original authors to obtain relevant information when collected data is insufficient. If the missing data are unobtainable, we will analyze the available data and describe it in the discussion. We will discuss the impact of missing data if necessary.
2.3.7. Subgroup analysis and investigation of heterogeneity. If data are available, we will perform subgroup analysis for different intervention forms. We will analyze different acupuncture therapy types, the age of patients, and other control interventions.
2.3.8. Ethics and dissemination. This review is aim to evaluate the safety and efficacy of acupuncture to treat ONP.
Formal ethical approval is not required, as the data are not individualized. The results will be disseminated through peer-reviewed publication.
2.3.9. Assessment of reporting biases. We will use a funnel plot to test reporting biases if more than 10 trials are included in the meta-analysis.