Who cites optometry journals?
Optometry journals have been published for over a century ; these play an important role in providing an evidence-based rationale for the procedures, techniques and treatment paradigms adopted by clinical optometrists. As well, optometry journals serve as a vehicle for testing information generated by scientists and academics working in the field, disseminating important findings to the optometric research community and beyond, and constitute as a valuable written repository for the work that is undertaken. Considerable human and physical resources, and significant associated fiscal expenditure, are required to sustain academic journals relating to a small discipline such as optometry, which perhaps raises the question of the value of these journals. The benefits of optometry journals to optometrists in clinical practice are difficult to measure objectively. Much of the evidence reported in optometry journals is eventually adopted by clinicians, whereby 'todays research becomes tomorrows practice' – a still-used theme first adopted in 2003 by the American Academy of Optometry. One difficulty that complicates the measurement of clinical impact of research is the time lag of knowledge translation from publication to clinical utilisation, which has been estimated to be around 17 years. , , From the perspective of optometric research, the question of value can be addressed by exploring the degree to which the information published in optometry journals is used, where it is used, and the impact of that usage. Examination of journal citations can assist in this regard. All scientific work relies on, and builds upon, previously published literature; invariably, scientific authors cite this literature at the end of papers they write. Modern bibliographic tools are available to search and analyse these citations, thus providing a means of assessing the extent to which specific research papers are valued, as well as the overall impact of a body of literature. Taking this a step further, the impact of entities such as journals, authors, institutions, or countries citing a defined body of literature can be evaluated by calculating the h-index – a single metric that combines productivity (number of papers) and quality (number of citations). The h-index of an entity is defined as the maximum value of h, whereby an entity has published h papers that have each been cited at least h times. The aim of this paper is to determine the extent to which articles published in optometry journals (referred to throughout this paper as ‘optometry articles’) are cited as a whole, and then to drill down to determine the most impactful papers and authors citing optometry articles, as well as the most impactful journals, institutions, and countries that cite the optometry journal literature. This will provide a quantitative assessment of the impact of optometry journals.   Search protocol A preliminary search was undertaken to find all optometry journals in the Scopus database (Elsevier). 'Optometric journals' were defined as journals with ‘optometry’, ‘optometric’ or ‘optometrist’ in the title, as well as journals that do not have the stem ‘optom’ in the title, but are principally organized by the optometric profession or a primarily optometric organization. Eighteen optometry journals were found; these are listed in , ranked in order of impact factor for year 2021 (Clarivate ), then the total number of papers for that journal on the Scopus database. A search term was derived to interrogate the Scopus database and find all articles published between January 1, 1970, and September 25, 2022, that cited at least one paper from any of the 18 optometry journals listed on that database (spanning from 1920 to the present time; see ). This search term used journal International Standard Serial Numbers (ISSN) or source titles. The search criteria were refined through several iterations, resulting in the following equation being derived: (ref ISSN (1040-5488) OR ref ISSN (0275-5408) OR ref ISSN (0816-4622) OR ref ISSN (0003-0244) OR ref ISSN (0817-881x) OR ref ISSN (1888-4296) OR ref ISSN (1705-4850) OR ref ISSN (1050-6918) OR ref ISSN (1529-1839) OR ref ISSN (0141-7037) OR ref ISSN (1444-0938) OR ref ISSN (0093-7002) OR ref ISSN (13670484) OR ref ISSN (0007-1218)) OR REFSRCTITLE (optomet*) OR REFSRCTITLE (hindsight AND saint AND louis AND mo) OR REFSRCTITLE (international AND contact AND lens AND clinic) AND (EXCLUDE (SRCTYPE, “b”) OR EXCLUDE (SRCTYPE, “Undefined”)) AND (EXCLUDE (DOCTYPE, “ch”) OR EXCLUDE (DOCTYPE, “bk”)) AND (LIMIT-TO (LANGUAGE, “English”)) Supplementary information included in this paper, such as the year range of publication of journals, professional and production publishers of journals, professional background of authors and organisational arrangements of institutions in respect of optometry schools, was determined by searching the internet for websites of the journals, authors and institutions of interest. Assessing impact A h-index for “optometry journal citations” (the “h OJC -index”) was derived, to serve as a measure of the impact of the search result across journals, authors, institutions, and countries. This technique has been used extensively by the current authors. , , , In brief, the h OJC -index of a given entity was determined by sorting the subset of optometry articles for that entity by rank order of citations to those articles (from highest to lowest) and working down the list, starting with the article that had the highest number of citations, to determine the article with a rank number that was larger than its number of citations. Taking the example of 'authors', the h OJC -index for that author was identified as the number of the entry above the identified article. This was repeated for each of the 100 most prolific authors of optometry articles; the top 20 were then identified and ranked in order of h OJC -index. The same approach was applied to identify the most impactful journals, institutions and countries that cite optometry articles.   A preliminary search was undertaken to find all optometry journals in the Scopus database (Elsevier). 'Optometric journals' were defined as journals with ‘optometry’, ‘optometric’ or ‘optometrist’ in the title, as well as journals that do not have the stem ‘optom’ in the title, but are principally organized by the optometric profession or a primarily optometric organization. Eighteen optometry journals were found; these are listed in , ranked in order of impact factor for year 2021 (Clarivate ), then the total number of papers for that journal on the Scopus database. A search term was derived to interrogate the Scopus database and find all articles published between January 1, 1970, and September 25, 2022, that cited at least one paper from any of the 18 optometry journals listed on that database (spanning from 1920 to the present time; see ). This search term used journal International Standard Serial Numbers (ISSN) or source titles. The search criteria were refined through several iterations, resulting in the following equation being derived: (ref ISSN (1040-5488) OR ref ISSN (0275-5408) OR ref ISSN (0816-4622) OR ref ISSN (0003-0244) OR ref ISSN (0817-881x) OR ref ISSN (1888-4296) OR ref ISSN (1705-4850) OR ref ISSN (1050-6918) OR ref ISSN (1529-1839) OR ref ISSN (0141-7037) OR ref ISSN (1444-0938) OR ref ISSN (0093-7002) OR ref ISSN (13670484) OR ref ISSN (0007-1218)) OR REFSRCTITLE (optomet*) OR REFSRCTITLE (hindsight AND saint AND louis AND mo) OR REFSRCTITLE (international AND contact AND lens AND clinic) AND (EXCLUDE (SRCTYPE, “b”) OR EXCLUDE (SRCTYPE, “Undefined”)) AND (EXCLUDE (DOCTYPE, “ch”) OR EXCLUDE (DOCTYPE, “bk”)) AND (LIMIT-TO (LANGUAGE, “English”)) Supplementary information included in this paper, such as the year range of publication of journals, professional and production publishers of journals, professional background of authors and organisational arrangements of institutions in respect of optometry schools, was determined by searching the internet for websites of the journals, authors and institutions of interest.   A h-index for “optometry journal citations” (the “h OJC -index”) was derived, to serve as a measure of the impact of the search result across journals, authors, institutions, and countries. This technique has been used extensively by the current authors. , , , In brief, the h OJC -index of a given entity was determined by sorting the subset of optometry articles for that entity by rank order of citations to those articles (from highest to lowest) and working down the list, starting with the article that had the highest number of citations, to determine the article with a rank number that was larger than its number of citations. Taking the example of 'authors', the h OJC -index for that author was identified as the number of the entry above the identified article. This was repeated for each of the 100 most prolific authors of optometry articles; the top 20 were then identified and ranked in order of h OJC -index. The same approach was applied to identify the most impactful journals, institutions and countries that cite optometry articles.   The search revealed that 82,830 papers have referenced optometry articles; these papers have in turn been cited a total of 2,054,816 times. The combined h OJC -index of this body of work is 370. A total of 13.9% of papers referencing optometry articles have received no citations. The time course of publication of the papers referencing optometry articles from 1970 to September 25, 2022 – is shown in . It is evident from this graph is that there has been a steady increase in the output of papers referencing optometry articles to over 6000 papers per year at the present time. Most impactful journals citing optometry articles The top 20 journals in the Scopus database which cite optometry articles are listed in in rank order of h OJC -indices, which range from 37 to 154. These top 20 journals can be categorised as: ophthalmology – 11; optometry – 4; vision science – 3; and general science – 2. The six highest ranking journals in are published in the United States. The three highest ranked journals are not optometric; these are Investigative Ophthalmology & Visual Science (h OJC = 154), Ophthalmology (h OJC = 133) and Vision Research (h OJC = 127). The highest performing optometric journal, at rank #4, is Optometry and Vision Science (h OJC = 113), with the other four optometry journals ranking #10, #14 and #16. The journals that have published the highest number of papers citing optometry articles are: Optometry and Vision Science – 5310 papers; Investigative Ophthalmology & Visual Science – 3139; Ophthalmic and Physiological Optics – 2170; and Clinical and Experimental Optometry – 2080. Most impactful papers citing optometry articles The top 10 most impactful papers citing optometry articles are shown in . These papers have been cited between 2223 and 5725 times. The most highly cited paper referencing optometry articles (5725 citations) is by Terwee et al., entitled ‘Quality criteria were proposed for measurement properties of health status questionnaires’, and published in Journal of Clinical Epidemiology . Only one of the 52 references in this paper was to an article in an optometric journal – Ophthalmic and Physiological Optics . One of the 10 most impactful papers citing optometry articles presented in was published in a vision science journal ( The Ocular Surface ), one appeared in an ophthalmology journal ( Survey of Ophthalmology ), and the rest appeared in a diverse array of journals, from the fields of epidemiology, psychology, oncology, allergy, neurology, neurophysiology, and general medicine. Most impactful authors of papers citing optometry articles The 20 most impactful authors of papers citing optometry articles are presented in and have h OJC -indices ranging from 43 to 69. The academic qualifications of these top 20 authors are: optometrist – 12; ophthalmologist – 4; optical physicist – 2; biostatistician – 1; and microbiologist – 1. The most impactful author of papers citing optometry articles is ophthalmologist Seang Mei Saw (h OJC = 69). None of the top 4 authors are optometrists; the highest-ranking optometrists are Karla Zadnik (rank #5; h OJC = 53) followed by Lyndon Jones (rank #6, h OJC = 51). The two most prolific authors of papers citing optometry articles in the top 20 are optometrists Nathan Efron ( n = 288 papers) and Lyndon Jones ( n = 282). Microbiologist Mark Willcox ( n = 256) is at rank #3. The top 20 authors who have published the highest percentage of papers citing optometry articles as a function of their total paper output are optometrists Jason Nichols (80%), Lyndon Jones (79%) and Michael Collins (73%). Five (25%) of the top 20 most impactful authors of papers citing optometry articles are female: ophthalmologist Seang Mei Saw (h OJC = 69), optometrists Karla Zadnik (h OJC = 53) and Fiona Stapleton (h OJC = 45), biostatistician Gladys Mitchell (h OJC = 45) and optical physicist Susanna Marcos (h OJC = 44). Most impactful institutions producing papers that cite optometry articles The top 20 institutions producing papers that cite optometry articles are listed in . The h OJC -indices of these institutions range from 71 to 127. The top-ranking institution is Harvard University, United States (h OJC = 127), followed by Johns Hopkins University, United States (h OJC = 111) and Moorfields Eye Hospital, United Kingdom (h OJC = 104). Thirteen of the top 20 institutions are home to optometry schools; of these, Ohio State University has the highest ranking (#5) (h OJC = 98). It should be noted that many of these institutions with optometry schools house ophthalmology academic units, which also contribute to these metrics. UNSW Sydney, Australia, has produced the highest number of papers citing optometry articles ( n = 1761), with the University of Melbourne, Australia ranked #2 ( n = 1650). The number of institutions from the various countries represented in are: United States – 11; Australia – 5; United Kingdom – 2; Singapore – 1; and Canada – 1. Most impactful countries producing papers that cite optometry articles The 20 most impactful countries producing papers that cite optometry articles are listed in . The h OJC -indices of the countries listed range from 21 to 313, and the paper count from 1142 to 28,485. The United States is the most impactful and prolific nation producing papers that cite optometry journals (h OJC = 313; n = 28,485) – having a substantially greater h OJC -index, and producing almost three times as many papers, as #2 ranked United Kingdom (h OJC = 200; n = 9788).   The top 20 journals in the Scopus database which cite optometry articles are listed in in rank order of h OJC -indices, which range from 37 to 154. These top 20 journals can be categorised as: ophthalmology – 11; optometry – 4; vision science – 3; and general science – 2. The six highest ranking journals in are published in the United States. The three highest ranked journals are not optometric; these are Investigative Ophthalmology & Visual Science (h OJC = 154), Ophthalmology (h OJC = 133) and Vision Research (h OJC = 127). The highest performing optometric journal, at rank #4, is Optometry and Vision Science (h OJC = 113), with the other four optometry journals ranking #10, #14 and #16. The journals that have published the highest number of papers citing optometry articles are: Optometry and Vision Science – 5310 papers; Investigative Ophthalmology & Visual Science – 3139; Ophthalmic and Physiological Optics – 2170; and Clinical and Experimental Optometry – 2080.   The top 10 most impactful papers citing optometry articles are shown in . These papers have been cited between 2223 and 5725 times. The most highly cited paper referencing optometry articles (5725 citations) is by Terwee et al., entitled ‘Quality criteria were proposed for measurement properties of health status questionnaires’, and published in Journal of Clinical Epidemiology . Only one of the 52 references in this paper was to an article in an optometric journal – Ophthalmic and Physiological Optics . One of the 10 most impactful papers citing optometry articles presented in was published in a vision science journal ( The Ocular Surface ), one appeared in an ophthalmology journal ( Survey of Ophthalmology ), and the rest appeared in a diverse array of journals, from the fields of epidemiology, psychology, oncology, allergy, neurology, neurophysiology, and general medicine.   The 20 most impactful authors of papers citing optometry articles are presented in and have h OJC -indices ranging from 43 to 69. The academic qualifications of these top 20 authors are: optometrist – 12; ophthalmologist – 4; optical physicist – 2; biostatistician – 1; and microbiologist – 1. The most impactful author of papers citing optometry articles is ophthalmologist Seang Mei Saw (h OJC = 69). None of the top 4 authors are optometrists; the highest-ranking optometrists are Karla Zadnik (rank #5; h OJC = 53) followed by Lyndon Jones (rank #6, h OJC = 51). The two most prolific authors of papers citing optometry articles in the top 20 are optometrists Nathan Efron ( n = 288 papers) and Lyndon Jones ( n = 282). Microbiologist Mark Willcox ( n = 256) is at rank #3. The top 20 authors who have published the highest percentage of papers citing optometry articles as a function of their total paper output are optometrists Jason Nichols (80%), Lyndon Jones (79%) and Michael Collins (73%). Five (25%) of the top 20 most impactful authors of papers citing optometry articles are female: ophthalmologist Seang Mei Saw (h OJC = 69), optometrists Karla Zadnik (h OJC = 53) and Fiona Stapleton (h OJC = 45), biostatistician Gladys Mitchell (h OJC = 45) and optical physicist Susanna Marcos (h OJC = 44).   The top 20 institutions producing papers that cite optometry articles are listed in . The h OJC -indices of these institutions range from 71 to 127. The top-ranking institution is Harvard University, United States (h OJC = 127), followed by Johns Hopkins University, United States (h OJC = 111) and Moorfields Eye Hospital, United Kingdom (h OJC = 104). Thirteen of the top 20 institutions are home to optometry schools; of these, Ohio State University has the highest ranking (#5) (h OJC = 98). It should be noted that many of these institutions with optometry schools house ophthalmology academic units, which also contribute to these metrics. UNSW Sydney, Australia, has produced the highest number of papers citing optometry articles ( n = 1761), with the University of Melbourne, Australia ranked #2 ( n = 1650). The number of institutions from the various countries represented in are: United States – 11; Australia – 5; United Kingdom – 2; Singapore – 1; and Canada – 1.   The 20 most impactful countries producing papers that cite optometry articles are listed in . The h OJC -indices of the countries listed range from 21 to 313, and the paper count from 1142 to 28,485. The United States is the most impactful and prolific nation producing papers that cite optometry journals (h OJC = 313; n = 28,485) – having a substantially greater h OJC -index, and producing almost three times as many papers, as #2 ranked United Kingdom (h OJC = 200; n = 9788).   The use of citation metrics to assess research impact does not have universal acceptance. The underlying assumption is that there is a direct association between the number of citations and the quality of the work, a view which is strongly supported by some bibliometric researchers, although disputed by others. Notwithstanding this difference of opinion, citation analysis is generally considered to be a useful objective tool for evaluating the impact of scholarly articles, and by extension, the impact of the authors, journals, institutions and countries generating these works. The increase in the number of papers citing optometry journals over the past half-century, as depicted in , and the substantial impact of this body of work as described above, is evidence of the growing value of optometry journals – not just to optometry, but the broader scientific fraternity that relies upon optometric research to support its own scientific advancements. Most impactful journals citing optometry articles It is not surprising that 15 of the top 20 journals (75%) are ophthalmic (i.e., 11 ophthalmology and 4 optometry journals). In any field of research, authors tend to cite papers that in some way support the work that is being reported, which therefore would be primarily derived from the literature base underpinning that field. The authors found 202 non-disambiguated ophthalmology journal names on the Scopus database, compared to 18 disambiguated optometry journal names. Therefore, given the substantial overlap in the subject matter reported by optometry and ophthalmology journals, it is not unexpected that almost three times as many ophthalmology journals cite optometry articles than optometry journals. These citation statistics demonstrate that optometry journals do not exist for the exclusive advancement of optometric science and the optometric profession; optometry journals are also used extensively and valued by ophthalmology researchers, in addition to vision scientists and general medical researchers. A total of 5310 papers in Optometry and Vision Science have cited optometry articles, which is considerably greater than second-ranked Investigative Ophthalmology & Visual Science (3139 papers). However, optometry article-citing papers published by Optometry and Vision Science (h OJC = 113) are less impactful than those published by Investigative Ophthalmology & Visual Science (h OJC = 154). The likely reason for this is that a substantial proportion of the papers published in Optometry and Vision Science , especially during the first 40 years of publications of that journal (say, 1924 to the 1960s), were editorials, professional commentaries, and clinical material such as case reports – material that tends not to be cited extensively. Conversely, Investigative Ophthalmology & Visual Science was established more recently (1962) as a 'science only' journal, and as such has generally publishes work that is more likely to be cited. The readership of Investigative Ophthalmology & Visual Science is also presumably much larger than that of Optometry and Vision Science . Most impactful papers citing optometry journals The broad spectrum of fields reflected amongst the most highly cited papers displayed in reinforces the notion that the optometry literature has value far beyond the ophthalmic domain. The 10 leading papers that cite optometry articles are themselves highly impactful, having been cited between 2000 and 6000 times. The impact of such publications can be appreciated when considering that only 0.03% of scientific papers have been cited more than 1000 times. Although 82,830 papers are known to have cited optometry articles, only 13.9% of these papers have never been cited themselves, attesting to the overall quality and impact of papers citing optometry articles. The balance of these papers has been cited over 2 million times, further demonstrating the importance of those works, and by extension their value in developing ideas or verifying factual information relating to vision science and beyond. Most impactful authors of papers citing optometry articles The most impactful author of publications citing optometry articles is Seang Mei Saw (h OJC = 69), who is professor of ophthalmology at the National University of Singapore. She holds a joint appointment at the Saw Swee Hock School of Public Health, and in that position has conducted several large-scale epidemiologic studies on myopia in children, as principal investigator. Given that the field of refractive error has always been a core area of optometric research and clinical practice, Professor Saw would have found it necessary to cite optometry articles extensively to support her writings. As an ophthalmologist, much of her work would be published in ophthalmology journals, which are known to generally have higher impact than optometry journals, hence the high impact of the papers authored by Professor Saw which cite optometry articles. For similar reasons, ophthalmologists Tienyin Wong (h OJC = 60) and Paul Mitchell (h OJC = 54) are ranked #2 and #4. The last column in shows, for each author, the proportion of papers citing optometry articles as a function of all papers published by that author. For the four ophthalmologists listed in this table (Seang Mei Saw, Tienyin Wong, Paul Mitchell and Kazuo Tsubota), none of whom work in university optometry departments, this proportion ranges from 12.4% to 33.0%. For the other 16 authors in , all of whom work in university optometry departments, the proportion ranges from 45.4% to 79.7%. This observation supports the notion that authors working in a given field are more likely to cite articles from journals relating to that field. The countries where the top 20 authors have spent most or all of their academic careers are: Australia – 8; USA – 7; UK – 2; Canada – 1; Japan – 1; and Singapore – 1. Most impactful institutions and countries producing papers that cite optometry articles The four highest ranking institutions listed in are the home of world-renowned ophthalmology departments, hospitals, or eye institutes. Much of the research generated by these institutions, which cites optometry articles, is typically published in high impact ophthalmology journals. The United States is the leading country for life sciences research, which is consistent with this nation producing papers of the highest impact, and the greatest volume of papers, that cite optometry articles. Comparison with other disciplines The volume of the body of papers citing optometry articles (82,830) and the associated measure of impact of these papers (h OJC = 370) can be compared with other disciplines by undertaking crude searches in Scopus. Articles published in dentistry journals been cited by a similar number of papers (80,101) to that of optometry; however, papers citing dentistry articles are less impactful (h OJC = 316) than those of optometry. The body of papers citing articles published in veterinary medicine journals is less extensive (42,208 papers) and less impactful (h OJC = 187) than that for optometry. The higher impact of papers citing optometry articles compared with papers citing dentistry or veterinary medicine articles is not related to the relative size of these professions; for example, there are approximately 165,000 dentists, 120,000 veterinarians and 40,000 optometrists in the United States. Given that citation metrics generally correlate with the size and reach of a discipline, the above comparisons could suggest that optometry journals that underpin the practice of optometry are disproportionately more valuable than those supporting dentistry or veterinary science.   It is not surprising that 15 of the top 20 journals (75%) are ophthalmic (i.e., 11 ophthalmology and 4 optometry journals). In any field of research, authors tend to cite papers that in some way support the work that is being reported, which therefore would be primarily derived from the literature base underpinning that field. The authors found 202 non-disambiguated ophthalmology journal names on the Scopus database, compared to 18 disambiguated optometry journal names. Therefore, given the substantial overlap in the subject matter reported by optometry and ophthalmology journals, it is not unexpected that almost three times as many ophthalmology journals cite optometry articles than optometry journals. These citation statistics demonstrate that optometry journals do not exist for the exclusive advancement of optometric science and the optometric profession; optometry journals are also used extensively and valued by ophthalmology researchers, in addition to vision scientists and general medical researchers. A total of 5310 papers in Optometry and Vision Science have cited optometry articles, which is considerably greater than second-ranked Investigative Ophthalmology & Visual Science (3139 papers). However, optometry article-citing papers published by Optometry and Vision Science (h OJC = 113) are less impactful than those published by Investigative Ophthalmology & Visual Science (h OJC = 154). The likely reason for this is that a substantial proportion of the papers published in Optometry and Vision Science , especially during the first 40 years of publications of that journal (say, 1924 to the 1960s), were editorials, professional commentaries, and clinical material such as case reports – material that tends not to be cited extensively. Conversely, Investigative Ophthalmology & Visual Science was established more recently (1962) as a 'science only' journal, and as such has generally publishes work that is more likely to be cited. The readership of Investigative Ophthalmology & Visual Science is also presumably much larger than that of Optometry and Vision Science .   The broad spectrum of fields reflected amongst the most highly cited papers displayed in reinforces the notion that the optometry literature has value far beyond the ophthalmic domain. The 10 leading papers that cite optometry articles are themselves highly impactful, having been cited between 2000 and 6000 times. The impact of such publications can be appreciated when considering that only 0.03% of scientific papers have been cited more than 1000 times. Although 82,830 papers are known to have cited optometry articles, only 13.9% of these papers have never been cited themselves, attesting to the overall quality and impact of papers citing optometry articles. The balance of these papers has been cited over 2 million times, further demonstrating the importance of those works, and by extension their value in developing ideas or verifying factual information relating to vision science and beyond.   The most impactful author of publications citing optometry articles is Seang Mei Saw (h OJC = 69), who is professor of ophthalmology at the National University of Singapore. She holds a joint appointment at the Saw Swee Hock School of Public Health, and in that position has conducted several large-scale epidemiologic studies on myopia in children, as principal investigator. Given that the field of refractive error has always been a core area of optometric research and clinical practice, Professor Saw would have found it necessary to cite optometry articles extensively to support her writings. As an ophthalmologist, much of her work would be published in ophthalmology journals, which are known to generally have higher impact than optometry journals, hence the high impact of the papers authored by Professor Saw which cite optometry articles. For similar reasons, ophthalmologists Tienyin Wong (h OJC = 60) and Paul Mitchell (h OJC = 54) are ranked #2 and #4. The last column in shows, for each author, the proportion of papers citing optometry articles as a function of all papers published by that author. For the four ophthalmologists listed in this table (Seang Mei Saw, Tienyin Wong, Paul Mitchell and Kazuo Tsubota), none of whom work in university optometry departments, this proportion ranges from 12.4% to 33.0%. For the other 16 authors in , all of whom work in university optometry departments, the proportion ranges from 45.4% to 79.7%. This observation supports the notion that authors working in a given field are more likely to cite articles from journals relating to that field. The countries where the top 20 authors have spent most or all of their academic careers are: Australia – 8; USA – 7; UK – 2; Canada – 1; Japan – 1; and Singapore – 1.   The four highest ranking institutions listed in are the home of world-renowned ophthalmology departments, hospitals, or eye institutes. Much of the research generated by these institutions, which cites optometry articles, is typically published in high impact ophthalmology journals. The United States is the leading country for life sciences research, which is consistent with this nation producing papers of the highest impact, and the greatest volume of papers, that cite optometry articles.   The volume of the body of papers citing optometry articles (82,830) and the associated measure of impact of these papers (h OJC = 370) can be compared with other disciplines by undertaking crude searches in Scopus. Articles published in dentistry journals been cited by a similar number of papers (80,101) to that of optometry; however, papers citing dentistry articles are less impactful (h OJC = 316) than those of optometry. The body of papers citing articles published in veterinary medicine journals is less extensive (42,208 papers) and less impactful (h OJC = 187) than that for optometry. The higher impact of papers citing optometry articles compared with papers citing dentistry or veterinary medicine articles is not related to the relative size of these professions; for example, there are approximately 165,000 dentists, 120,000 veterinarians and 40,000 optometrists in the United States. Given that citation metrics generally correlate with the size and reach of a discipline, the above comparisons could suggest that optometry journals that underpin the practice of optometry are disproportionately more valuable than those supporting dentistry or veterinary science.   Optometry journals are cited extensively by optometrists, ophthalmologists, and vision scientists world-wide, as well as authors from a broad spectrum of non-ophthalmic research domains. That around 6000 scientific papers citing optometry articles are published annually is an indication of the intrinsic value of the information generated by optometry journals, in a sense providing a raison d'être for the very existence of optometry journals and a justification for the ongoing support to publish such journals by optometric professional organisations.   The authors of this work are identified as leading authors citing optometry articles, from which they stand to derive reputational benefit. The authors also declare the following: Nathan Efron : Over the past three years: Lecture honoraria from CooperVision and Johnson & Johnson Vision Care; consulting fees from Procter & Gamble. Lyndon Jones : Over the past 3 years Dr Jones’ research group (CORE) or he personally has received research support or lectureship honoraria from: Alcon, Allergan, CooperVision, GL Chemtec, iMed Pharma, J&J Vision, Lubris, Menicon, Nature's Way, Novartis, Ote, PS Therapy, Safilens, Santen, Shire, SightGlass and Visioneering. Dr Jones is also a consultant and/or serves on an advisory board for Alcon, CooperVision, J&J Vision, Novartis and Ophtecs. Jason Nichols : Over the last 3 years, Dr. Jason J. Nichols has received honoraria from Paragon Vision Sciences and CooperVision. He has also received research funding from Alcon, Bruder, Johnson and Johnson Vision, and Mallinckrodt. Also, Dr. Kelly Nichols is the spouse of Dr. Jason Nichols, extending her declarations to him. In the past 12 months, Dr. Kelly Nichols has consulted for and received honorarium from: Bruder, Dompe, Kala, Novartis/Shire (Medical Exchange International), Osmotica, Oyster Point, Sight Sciences, Tear Film Innovations/Alcon/Acquiom, Thea, Tarsus, and TopiVert. She has received research funding from: Allergan, Kala, and Tear Science. Phillip Morgan : Dr Morgan or his research group, over the past three years, have received research funding and/or honoraria from: Alcon, AMCo, CooperVision, Essilor, Johnson & Johnson Vision, Menicon, RB, Shire and Ultravision.   