A bibliometric analysis of systematic reviews and meta-analyses in ophthalmology

Abstract

Background: Bibliometric analysis is a quantitative method which applies mathematical and statistical tools to evaluate the inter-relationships and impacts of publications, authors, institutions and countries in a specific research area. Systematic reviews and meta-analyses (SRMAs) are summaries of the best available evidence to address a specific research question via comprehensively literature search, in-depth analysis and synthesis of results. To date, there have been several studies summarizing the publication trends of SRMAs in research specialties, however, none has conducted specifically in ophthalmology. The purpose of this study is to establish the scientometric landscape of SRMAs published in the field of ophthalmology over time.

Methods: We retrieved relevant ophthalmological SRMAs and the corresponding bibliometric parameters during 2000 to 2020 from Web of Science Core Collection. Bibliometric analysis was performed using bibliometrix package. Pre-registration and guideline compliance of each article was independently assessed by two investigators.

Results: A total of 2,660 SRMAs were included, and the average annual growth rate was 21.26%. China and the United States were the most productive countries, while Singapore was the country with the highest average citations per document. Wong TY was not only the most productive, but also the most frequently cited author. The most productive affiliation was National University of Singapore (n = 236). Systematic reviews and meta-analyses output in most subspecialties had steadily increased with retina/vitreous (n = 986), glaucoma (n = 411) and cornea/external diseases (n = 303) constantly as the most dominant fields. Rates of pre-registration and guideline compliance had dramatically increased over time, with 20.0 and 63.5% of article being pre-registered and reported guideline in 2020, respectively. However, SRMAs published on ophthalmology journals tended to be less frequently pre-registered and guideline complied than those on non-ophthalmology journals (both p < 0.001).

Conclusion: The annual output of SRMAs has been rapidly increasing over the past two decades. China and the United States were the most productive countries, whereas Singapore has the most prolific and influential scholar and institution. Raising awareness and implementation of SRMAs pre-registration and guideline compliance is still necessary to ensure quality, especially for ophthalmology journals.

Keywords: bibliometric analysis; ophthalmology; publication productivity; research trend; systematic reviews and meta-analyses.

Figure 1

Flow diagram demonstrates the screening process of systematic reviews and meta-analyses in ophthalmology.

Figure 2

Author production and collaboration. (A) Top 10 productive authors. (B) Top 10 productive authors. (C) Top 10 relevant affiliations. (D) Collaboration network at author-level. The thickness of the line is proportional to the strength of co-authorship. Top 10 productive authors are highlighted in red.

Figure 3

Country production and citation. (A) A heat map is presented displaying the number of publications from different countries according to the occurrence of authors. (B) Corresponding author’s country. (C) Top 10 cited countries. SCP, single country publication; MCP, multiple country publication.

Figure 4

Publication in subspecialties. (A) Numbers of publications in different ophthalmological subspecialties. (B) The trends of publications in five major ophthalmological subspecialties from 2000 to 2020. (C) The proportion of different types of study content in five major ophthalmological subspecialties. (D) A Sankey diagram reveals the relationship between subspecialties and different bibliometric indicators.

Figure 5

The percentage of pre-registered studies (A) and guideline complied studies (B) indexed by web of science core collection over time.