GLOBAL PATTERNS AND RESEARCH DYNAMICS OF EXTENDED DEPTH-OF-FOCUS (EDOF) INTRAOCULAR LENSES: A BIBLIOMETRIC OVERVIEW

To map global research activity, collaboration patterns and influential publications on extended depth-of-focus (EDOF) intraocular lenses through bibliometric analysis using co-authorship and bibliographic coupling networks.

Department of Ophthalmology, Faculty of Medicine, Istanbul University, Istanbul, Türkiye.

Bibliometric analysis was conducted in the Web of Science Core Collection (2003–2025) using “EDOF” as the primary term under Advanced Search – All Fields. To broaden retrieval, the keywords “enhanced depth of focus”, “extended depth of field”, “extended depth of focus”, “extended range of vision”, “extended depth of focus intraocular lens”, and “extended depth of focus IOL” were included. Limiting records to articles, reviews, and book chapters within ophthalmology and surgery yielded 491 documents. Analyses were performed in VOSviewer v1.6.20, using co-authorship (authors, organizations, countries) and bibliographic coupling (documents, sources) networks. Total Link Strength (TLS) measured collaboration or citation connection strength. Data extracted from Web of Science (Oct 10, 2025).

A total of 491 publications met inclusion criteria. In the author co-authorship analysis (max 25 authors/document; min 5 documents/author), 50 of 1,758 authors met thresholds. The most productive contributors were Ramin Khoramnia (25), Gerd U. Auffarth (22), and Thomas Kohnen (16). The most cited were Auffarth (508 citations), Kohnen (419), and Khoramnia (388), with the strongest networks (TLS) for Khoramnia (65), Auffarth (62), and Son Hyeck-Soo (41). Among 877 institutions, 34 met criteria (≥5 documents). The most productive were Complutense University of Madrid (UCM; 17), Heidelberg University (17), and University of New South Wales (UNSW; 16). The most cited were Goethe University (392), UNSW (386), and University of Verona (320), while the highest TLS values occurred at UNSW (12), UCM (12), and Heidelberg (8). At the country level, 26 of 50 countries met thresholds (≥5 documents). The United States led with 113 publications and 1,671 citations, followed by Germany (80 documents, 1,418 citations) and Spain (79 documents, 2,453 citations). In the bibliographic coupling analysis (≥100 citations/document), 12 of 491 papers qualified. The most cited were Cochener’s 2016 study (175 citations), Cochener’s 2018 study (172), and Rampat’s 2021 paper (168). Among 60 journals, 24 met inclusion criteria (≥5 documents). The most productive were Journal of Refractive Surgery (63), Journal of Cataract and Refractive Surgery (60), and Clinical Ophthalmology (58); the most cited were JCRS (1,546 citations), JRS (1,307), and Clinical Ophthalmology (701).

EDOF intraocular lenses are increasingly used to provide an extended visual range with fewer disturbances. This bibliometric analysis maps the research landscape to guide future studies by highlighting leading authors, institutions, and journals, streamlining literature review in presbyopia-correcting IOL research.