The increasing global prevalence of diabetes has made it a significant health issue and socioeconomic burden, with more than 600 million individuals projected to be affected by diabetes by 2040 (1). Diabetes-related eye diseases, which manifest early in the course of diabetes, are a leading cause of blindness in both developed and developing countries (2). Initially, diabetic retinopathy and cataracts were the primary focus. However, with advancements in diagnostic techniques, diabetic keratopathy (DK) has garnered increasing attention from clinicians and researchers (3, 4).

DK encompasses a range of corneal alterations caused by diabetes, varying in form and severity. Clinically, DK manifests as superficial punctate keratopathy, delayed epithelial healing, persistent epithelial defects or recurrent erosions, nerve loss, decreased corneal sensitivity, tear film changes, ulcers, and opacities (5, 6). These changes impair patients’ quality of life and vision to varying degrees and are often underestimated in clinical settings, with conventional treatments yielding limited efficacy (7). Understanding the pathogenesis and key factors of DK is crucial for effective treatment.

Bibliometrics, involving the quantitative analysis of scientific publications using mathematical and statistical methods, focuses on citations, publications, co-authorship, journals, keywords, and research trends. Analyzing a large volume of literature provides insights into the structure, development, and dynamics of a field, guiding future research and development (8, 9).

In this study, we employed bibliometric methods to analyze literature on diabetic keratopathy published since the new millennium and presented our findings with visualization software. Our analysis addresses four questions: 1. What are the research trends in diabetic keratopathy? 2. Which countries, institutions, and authors are influential in this field? 3. What are the collaboration networks among leading institutions and authors? 4. What are the current research hotspots, keywords, and potential future directions in this field?

Past research on diabetic ocular complications primarily focused on diabetic retinopathy due to its severe impact on vision (10–12). However, DK is gaining increasing attention from researchers worldwide for two main reasons (13, 14). First, the prevalence of DK continues to increase with the increasing number of diabetes patients and the prolonged duration of the disease. Second, with the application of confocal microscopy, observing the morphology and quantity of corneal nerves has become an important surrogate marker for evaluating peripheral neuropathy in diabetic patients (15–17).

The increasing number of publications also confirms that DK is receiving more attention. The annual publication volume in this field shows a year-on-year increase, with explosive growth, especially after 2013. This surge is mainly due to the application of confocal microscopy, which allows for more intuitive observation of nerve damage in patients with DK. Additionally, damage to corneal nerve tissue serves as an important indicator for evaluating peripheral neuropathy in diabetic patients (17–19). The publication volume has not shown any decline in recent years, indicating that research in this field remains a hotspot.

Analyzing publications by country, institution, and author reveals the global distribution and characteristics of research in this field. Although the United States and China lead in terms of publication volume, their citation rates are not very high, and they share the same collaboration cluster. In contrast, England, Australia and Qatar have high citation rates, with the England-Australia-Qatar collaboration cluster being a key research focus. The University of Manchester in the UK, which ranks first in both the number of publications and citations, is especially noteworthy. The University of Queensland in Australia is also a research hub in this field for the country, ranking second in publication volume and having a high number of citations. Malik Rayaz from Qatar is the most prolific researcher in this field, making Qatar a leading research frontier, on par with traditionally developed countries such as the UK and Australia. Nathan Efron from Australia ranks second in publication volume and collaborates closely with Malik Rayaz. It is believed that core researchers like Malik Rayaz and Nathan Efron have made the UK-Australia-Qatar research collaboration circle the current global core in this field.

Research outcomes in this field are primarily published in ophthalmology and diabetes journals. Although more articles are published in ophthalmology journals, those in diabetology journals have higher impact factors and receive more citations. The main reason is that diabetes and its peripheral neuropathy constitute a larger research area, leading to a greater impact factor and more frequent citations for related articles (20, 21). Despite the lower impact factors of ophthalmology journals, those such as IOVS and Cornea are very influential within the ophthalmology field and merit attention from researchers (22, 23). Moreover, the research focus of articles published in ophthalmology journals differs from those in diabetes journals. Articles published in the diabetes journals primarily focus on corneal nerve damage detected by confocal microscopy, which serves as an indicator of diabetic peripheral neuropathy. In contrast, articles published in ophthalmology journals cover various aspects of diabetic keratopathy.

High-citation articles and main keyword analysis indicated that past research focused on observing diabetic corneal neuropathy and structural changes via cornea confocal microscopy. Studies have shown that diabetic patients have reduced corneal nerve fiber density, nerve branch density, and nerve fiber length (17, 18, 24). Damage to the corneal nerves in diabetic patients not only leads to decreased corneal sensitivity, making them more susceptible to external injuries, but also results in a reduction of neurotrophic substances in the corneal tissue (25–27). This lack of nutrients impairs the function of corneal stromal cells and epithelial cells. Additionally, corneal nerve fibers are crucial for maintaining healthy corneal epithelium and promoting wound healing after ocular trauma (28, 29). The loss of these nerve fibers leads to corneal epithelial damage and persistent nonhealing wounds. Moreover, confocal microscopy revealed a decrease in corneal epithelial cell density in diabetic patients, along with reduced activation and migration of these cells postinjury (30–32). Similarly, corneal stromal cells and endothelial cells in diabetic patients are also affected to varying degrees, showing a decrease in numbers (33, 34).

From the analysis of keyword clustering over time, time zone maps, and burst word analysis, we find that terms like “ocular surface”, “tear film” and “dry eye” have become hotspots in recent years. This shift indicates a broader interest beyond corneal pathology to the entire ocular surface, including the conjunctiva and tear film. Diabetic patients exhibit decreased tear film stability, increased osmolarity, and elevated levels of advanced glycation end products and inflammatory factors, all of which are detrimental to corneal epithelial repair (35–37). Immune cell activation, proteomic changes, and reduced mucin secretion in the conjunctiva also impact diabetic keratopathy to varying degrees (38, 39).

Keyword analysis also revealed that research on the mechanisms of DK and its associated neural damage is still limited. Previous studies have suggested that oxidative stress, neurotrophic deficits and inflammatory mechanisms play crucial roles in the pathogenesis of diabetic corneal neuropathy (40–42). Corneal epithelial damage is mainly related to the accumulation of advanced glycation end products on the ocular surface due to hyperglycemia (43, 44). Corneal stromal damage is linked to hyperglycemia-induced disruption of collagen subtypes and proteoglycans, affecting the structural integrity of the cornea (45, 46). These mechanisms are not prominent in the keyword network, suggesting that these areas have not yet become central to research in this field. Researchers need to further explore the key mechanisms underlying DK, or perhaps the pathogenesis of DK is multifactorial, lacking a single core mechanism.

This study systematically analyzed the literature on diabetic keratopathy published since 2000. We found that this field is gaining increasing attention and research interest. Visualization analysis provides a clear and rapid understanding of the current research status, collaboration networks, and research hotspots. Analyzing these hotspots suggests that future research may focus on the mechanisms of diabetic corneal neuropathy.