The 100 most influential articles in myopia: a bibliometric analysis

INTRODUCTION

Myopia (short-sightedness or near-sightedness) is becoming a major public health concern and is causing a huge economic burden. The prevalence of myopia has expanded greatly over the past 50-60y and has reached epidemic levels in young adults in East and Southeast Asia. With the increasing attention of myopia, a large volume of studies are published every year to provide new insights into the development of myopia, and treatment techniques have undergone a seismic revolution of the last decades.

Literature retrieval, screening and analysis follow the methods established in previously published articles. The Web of Science (WOS) Core Collectiondatabase was used for conducting a literature search on March 25, 2020. The index terms used for the search were “TOPIC:(myopia) OR TOPIC: (myopic) OR TOPIC: (nearsightedness)OR TOPIC: (shortsightedness) OR TOPIC: (near-sighted) OR TOPIC: (short-sighted) OR TOPIC: (high myopia) OR TOPIC:(pathological myopia)”, a year of publication ranging from 1975 until 2020. Languages, document type and the WOS category were not restricted in the search.

总体上正在向多样化发展，四川、青海等省份制定了旅游产业发展大会申办办法，每年举办旅游节事活动和招商活动，中国医疗保健国际交流促进会开辟了多种国际交流途径。涉外活动也越来越受到大众关注，仅2018年以来，就先后举行了多场与健康旅游相关的重量级活动，博鳌“一带一路”与健康产业发展论坛在海南博鳌举办，国际中医药文化节首次登陆中国内地，世界中医药学会联合会首届非物质文化遗产高峰论坛在北京举行。2020年，北京还将举办世界休闲大会，倡导休闲生活，发展健康旅游。与“引进来”形成对比的是，“走出去”推介的力度还显不够。

水利质量检测人员的专业能力直接影响着质量检测的结果，所以水利企业要重视质量检测人员的能力培训，定期的组织质量检测人员进行专业培训，这样可以有效地提高他们的质量检测能力，还要对检测人员进行职业素养教育，让他们具备较高的社会责任心和职业素养，这样才能在质量检测的过程中切实的负起责任，按照相关的标准要求规范检测，保证质量检测的准确性和真实性。另外，水利企业招聘质量检测人员的时候，要尽可能多招聘一些专业的质量检测人才，并且要质量检测经验丰富的，这样更能保证质量检测的准确性。

云计算作为一种全新的互联网应用模式，将成为未来人们获取服务和信息的主导方式[5]。云计算是一种方便的使用方式和服务模式，通过互联网按需访问资源池模型(例如网络、服务器、存储、应用程序和服务)，可以快速地管理工作，为用户提供服务[6]。云计算技术相关研究得到大力推动并继续稳步、快速、深入进行。与此同时，随着新业务需求日益增长，基于云计算平台的各种应用不断涌现。白酒行业在保留传统工艺的基础上，引入现代化云计算技术来提升白酒发酵的精细化水平，对提高成品酒质量具有重要意义。基于云计算平台的白酒发酵智能专家系统在此基础上展开。

MATERIALS AND METHODS

In addition to the impact factor (IF) of journals, the number of citations of an article is also an important reflection of its contribution to that particular field. Bibliometric analysis can reveal the evolution of a field by objectively identifying seminal studies among a population of papers. Since Garfield published the first bibliometric study inin 1987, this field has been developed and more and more articles have been published.

在划定的地下水资源开发区，科学勘察，合理布置井位，采用先进的机械设备和现代化的工艺凿至含水层，用井管保护井壁，以获取深层地下水来满足饮水需求。

A total of 22 509 published articles were retrieved, and then these articles were sorted in descending order according to total citations (TCs). Articles conforming to the abovementioned conditions were evaluated and preliminarily analyzed by two independent readers (Wang XJ and Chou YY) to ensure its relation to myopia. The 100 most cited articles were determined by reviewing the titles and abstracts of these articles, and the full text if necessary. Articles focusing only on animals (, chickens and monkeys) were excluded from the screening process.

The 100 most cited articles that meet the screening criteria were then analyzed further. Article title, first and corresponding authors, journal, 2018 IF of Journal Citation Reports (JCR), IF of most recent 5-year, publication date,country of origin, institution, TCs, annual citations (ACs),citation number of most recent 5-year, research focus and study type were recorded for the top 100 most influential articles on myopia. The number of ACs was calculated by dividing TCs by the number of years since the manuscript was published.

The data were usually distributed in the form of mean and standard deviation, while the skewed data were presented in the form of median and range. The Shapiro-Wilk test was used to test the normality of the distribution of individual variables. Correlations among non-parametric variables were evaluated by Spearman’s correlation analysis.Mann-Whitneytest was used to compare the difference between non-parametric variables. Analyses were performed with SPSS v.25 (IBM Corp., NY, USA). A two-sided-value<0.05 was considered to be statistically significant.

RESULTS

A total of 22 509 papers related to myopia were published from the WOS Core Collection database. These papers were sorted by TCs, and the top 100 papers in the field of myopia were identified. The details of the top 100 most cited articles can be found in Supplementary Table 1.

The 100 most influential articles were published between 1983 and 2016. Most of them were published between 2000 to 2009 (=60), followed by 1990-1999 (=28) and 2010-2019 (=10), whereas only 2 articles were published between 1980 to 1989 and none before 1980.Figure 1 shows TCs for every paper in each year. Figure 2 shows the number of papers in each year. The TCs of an article was independent of its publication date (>0.05). However,the number of ACs and citations in recent 5y are significantly correlated with publication date (=0.774,<0.01;=0.597,<0.01).

Among the top 100 most-cited articles, 85 were original articles and 15 were review articles. Three of the 15 review articles were systematic reviews and Metaanalysis. The highest TCs and ACs articles among the 100 most-cited articles were both review articles from Australia.The original articles comprised 52 observational studies and 33 experimental studies, the latter covers 10 randomized controlled trials (RCTs). Observational studies consisted of 38 cross-sectional studies, 6 cohort studies, 5 case series, and 3

case‐control studies. According to the time logic classification,the original articles included 38 cross-sectional studies, 37 prospective studies, and 10 retrospective studies. There was no difference in the number of TCs between the original articles and the review articles (Mann-Whitneytest=0.141), while the number of ACs of review articles was significantly higher than that of original articles [Mann-Whitneytest<0.05,median=22, range (9-109)median=17, range (7-45)].

(2)专业知识。具体到客服人员涉及的行业与企业，专业知识主要体现在行业背景、业务流程、产品知识、营销知识、心理学知识等。

A total of 28 772 citations were obtained for the top 100 most influential articles. The number of TCs was highest at 537 for Morganand lowest at 193 for Goh.The number of ACs was highest at 109 for Holden. The median number of TCs and ACs were 266 and 16. Ninety-one articles were cited more than 200 times and 14 papers were cited more than 400 times. Table 1 shows the top 10 articles ranked by ACs.

Spearman correlation analyses revealed a significant positive association between the trends of TCs and ACs (=0.572,<0.01). Five of the top 10 articles ranked by TCs were listed in the top 10 articles ranked by ACs. The numbers of ACs of articles published in recent 10y [median=44, range (21-109)] were significantly higher than that of the other mostcited articles [median=16, range (7-45); Mann-Whitneytest,<0.01]. Nevertheless, there was no such correlation for the average number of TCs (Mann-Whitneytest=0.667). The recent 5-year citation number was also positively correlated with TCs (=0.477,<0.01). We believe that the number of citations in the last 5y can reflect the current research hotspots and trends better than TCs.

With too many medical papers indexed in the database every day, it is difficult for clinicians and researchers to quickly find important articles in their fields of interest in the vast ocean of digital information. The bibliometric analysis can determine the most influential articles in a certain field of interest, and help clinicians and researchers grasp the changing pattern of clinical practice, current research priorities, and research trends in the future. We conducted a bibliometric analysis of articles in the field of myopia and identified the 100 most influential articles, aiming to systematically determine the research trend of myopia.

The top 100 most influential papers were published in 21 journals. The journals of publication, journal IF according to the 2018 JCR and TCs for each journal are listed in Table 2. Specialized journals published most (94%) of the top 100 articles, leading with(29 papers and 8122 citations) and(23 papers and 6531 citations). None of the specialized journals listed in Table 2 had an IF of more than 12. Generalized journals published 6 papers and the IFs were all greater than 12. Thehad the highest IF of 59.1, and its only article is also the article with the most TCs. The IF is not statistically correlated with TCs (>0.01).

Uncorrected or undercorrected myopia is the main cause of visual impairment, and it has become an increasingly serious public health problem worldwide. Myopia brings further vision challenges since high myopia multiplies the risk of pathologic changes such as glaucoma, cataract, and myopic macular degeneration. The global potential productivity loss in 2015 was estimated at $244 billion from uncorrected myopia and $6 billion from myopic macular degeneration.

Bibliometric analysis has been widely used in several medical fields, such as asthma, obesity, diabetes, orthopedics, liver cancer, and pituitary adenoma. A number of bibliometric studies have also been published in the field of ophthalmology,such as cataract surgery and dry eye. However, similar bibliometric studies have not been conducted in the field of myopia. In this study, we aimed to identify and characterize the basic characteristics of the 100 most cited articles in myopia in recent few decades. We also intend to identify factors that contribute to the increase in citations, such as journals and publication time.

CBTC(基于通信的列车控制)系统能够确保列车灵活、高效运行。但近年来，采用CBTC系统的线路仍时有事故发生。2011年9月11日，上海轨道交通10号线发生列车追尾事故，造成295人受伤；2017年11月15日，新加坡地铁发生列车碰撞事故，造成28人受伤。这些事故都造成了巨大的社会影响和经济损失。事故原因是，CBTC系统地面设备故障，事故列车无法识别其他列车，因而不能实施有效控制。那么，如果列车具有自主运行能力，并且各车之间能够直接通信，就可有效避免列车追尾或碰撞事故的发生。这一技术将成为新一代CBTC系统的一个重要着力点。

DISCUSSION

The top 100 most cited articles were originated from 14 countries led by the United States (=43; Figure 4). The most productive institution with the highest TCs was the National Institutes of Health (NIH)of USA, which has published 12 articles and the TCs reached 3655. The top 7 institutes or academies contributing to the top 100 most-cited articles were listed in Table 3. Leon B.Ellwein’s from the National Eye Institute of NIH has published the largest number of most influential articles on myopia (=9)and was thus the most-cited author in this field. The authors with more than three articles were listed in Table 4.

水分是行鞭、孕笋的一个重要条件，当夏季连续高温干旱时，进行补水；补水应选择晚上温度回落后进行，补水量以林地浇透即可。8月底至9月中下旬，如再遇连续干旱，可再行浇灌补水1次，用量与前次相当。

Treatment (=27) and prevalence (=27)of myopia was the most widely studied topic, accounting for more than half of the top 100 papers. Figure 3 shows the topics of articles. Among 38 studies focused on treatment and surgical complications of myopia, 25 were related to laser in situ keratomileusis (LASIK) and excimer laser photorefractive keratectomy (PRK), 3 for femtosecond laser small incision lenticule extraction (SMILE) and 3 for orthokeratology. The geographical range of epidemiological research was vast,including China, USA, India, Nepal, Singapore, Australia,Japan, South Africa, Malaysia, Chile and Western Europe. Of the 15 articles that studied the etiology of myopia, 10 articles studied children or teenagers. The most studied risk factors were parental history, near work, outdoor activities and genes.

The number of citations of a paper has become a valuable indicator for evaluating the efforts made by authors and journals as a measure of its impact on a particular field. The TCs of the 100 most influential articles in myopia ranged from 193 to 537. This number is considerably higher than that in dry eye, for which the TCs ranged from 96 to 610, and cataractsurgery, for which the TCs ranged from 85 to 281. When the table is sorted in descending order according to ACs, the influence of year of publication on TCs can be reduced. The correlation between ACs and publication date indicated that the newer the literature, the more likely it is to cover the topics of the greatest concern among eye care professionals. The most-cited paper is “Myopia” by Morganpublished in Thein 2012. This is a comprehensive review article of the biological basis, definition, epidemiology, pathology, risk factors of myopia, as well as interventions to control myopia.IF can only represent the quality of the journal in a certain specialty and not enough for assessing the impact of specific articles. Spearman’s correlation analysis showed the correlation between the ⅠF and TCs is not statistically significant. This may due to that almost all of the 100 most influential papers were published by journals in the ophthalmology category, and the IF of these journals were not as high as that of comprehensive journals. Among all journal categories ranked by the number of journals in 2018 JCR (a total of 236 categories),ophthalmology ranks 126with 60 journals, with a median IF of 1.889 and aggregate IF 2.551.

Treatment of myopia is the most studied topic, with 38 articles published after 1990. From these articles, we can discern the various intervention to control myopia and the main evolution course of refractive surgery over the past decades. Most articles published around the 1990s were about PRK and LASIK. In 1991, Seiler and Wollensakproved PRK is an efficient procedure to correct or lower myopia up to -7.0 D. An RCT conducted by Pallikaris and Siganosin 1994 concluded LASIK was more effective than PRK in higher myopes. In 1999, Oshikafound PRK and LASIK increase the wavefront aberrations of the cornea and change the relative contribution of coma- and spherical-like aberrations. This finding attributed to the smaller transition zone of the laser ablation in the LASIK. The 3 articles about SMILE were published during 2008-2011. Sekundoconducted the first prospective clinical experiment in Germany to evaluate the feasibility of femtosecond lenticule extraction(FLEx) in 2008 and performed myopic FLEx through a small incision using SMILE procedure in 2011. He found SMILE was a promising new flapless minimally invasive refractive procedure to correct myopia. In 2008, Shahin India carried out the first clinical study outside Germany performing SMILE with a single incision, proving all-in-one femtosecond refractive correction using a small incision technique was safe, predictable, and effective in treating myopia and myopic astigmatism. In 2004, the FDA performed a prospective clinical trial of implantable collamer lens (ICL) surgery and results supported the safety, efficacy, and predictability to treat moderate to high myopia. In 2005 and 2012, Chopublished 2 studies confirming orthokeratology had both corrective and preventive/control effects in childhood myopia. In 2006, Chuaconducted an RCT and proved topical atropine was well tolerated and effective in slowing the progression of myopia and ocular axial elongation in Asian children.

Epidemiology is also a popular topic of myopia, with a total of 27 articles. The geographical range of epidemiological research was vast, with 8 articles from China and 5 articles from the United States, and also included India, Nepal,Singapore, Australia, Japan, South Africa, Malaysia, Chile and Western Europe. The U.S. NIH contributes 12 articles in the field of epidemiology of myopia. The article with the largest ACs, entitled “Global prevalence of myopia and high myopia and temporal trends from 2000 through 2050”, is a systematic review and Meta-analysis published inin 2016, exerting far-reaching influences on the estimation of the prevalence trends of myopia. In this article, Holdenincluded data from 145 studies covering 2.1 million participants and predicted that by 2050, myopia will show a significant increase in prevalence globally, affecting almost 5 billion people (50% of the world population), of which nearly 1 billion are high myopia (9.8% of the world population). The prevalence of myopia in high-income countries in the Asia-Pacific region is much higher than in any other region, and all regions will increase year by year over time. In 2000, the most myopic patients were between 10 and 39 years old. However,the research showed that this distribution will expand in 2050 due to the cohort effect and age effect, and most myopic patients will last between the ages of 10 and 79.

These 100 citations are landmark articles that have inspired clinical and basic research in myopia over the past decades.Our research may be worthwhile for several reasons. First of all, we found that myopia is a booming research hotspot, and the exploration on its epidemiology and treatment is in the ascendant. Second, our study offers new and old generations hints about what makes an article a most frequently cited classic. The eye care professors and their groups have to propose a surgical or medical innovation, worldwide influential clinical description, or discovery that has a long‐lasting effect on clinical practice. Third, the top 100 articles reflect the major evolution of the treatment of myopia. In recent years,corrective treatment has shown a diversified trend, with treatment methods including PRK, SMILE, and ICL. Last but not least, our observations show that the authors of citation classics in myopia have produced more highly cited articles than many colleagues in other ophthalmology specialties.Of course, some limitations of this study cannot be ignored.First, we selected the WOS database that is most commonly used in bibliometrics research, which resulted in the neglect of documents from other databases. Second, due to the use of TCs for evaluation, the importance of recently published articles may be weakened. Finally, we did not analyze selfcitation, citations in textbooks, and lectures. Inappropriate selfcitations might influence the results of the analysis. Some of the authors may have cited articles from the journal in which they hoped to publish their research. There may be “snowball effect” which means the previously high‐cited articles may be cited more not because of their values but simply due to the tendency of complying with an established paradigm.In conclusion, we conducted a bibliometric analysis of studies in the field of myopia, and identified the 100 most influential articles that have had the greatest impact on myopia research in the past few decades. This study emphasizes significant contributions in the field of myopia research, from which we can explore the future perspectives of myopia research.

The authors would like to thank Dr. Bao Jin, MD., Department of Liver Surgery, Peking Union Medical College Hospital, for his kind help and advices regarding this article.

Zhong Y, Li Y, and Luo Y conceived the study; Wang XJ and Chou YY collected the data; Wang XJ, Chen D and Jiang Y participated in data analysis and interpretation; Wang XJ wrote the first draft; Zhong Y and Ma J revised the manuscript. All authors read and approved the final manuscript.

None;None;None;None;None;None;None;None.