The inclusion criteria were as follows: (i) articles related to TCM treatment for asthenopia; (ii) journal articles; and (iii) articles containing complete information, including publication date, author, institution, and keywords.

The exclusion criteria were as follows: (i) studies unrelated to TCM treatment for asthenopia; (ii) repeatedly published articles; (iii) retracted publications; and (iv) meeting documents, news, advertisements, patents, and popular science articles.

Data from WOS and PubMed were exported in plain text format with complete records and references. Data from CNKI and Wanfang were presented in “refworks” format and converted to the download_***.txt format for use. CiteSpace software (V6.4. R1) to examine and organize the articles. The data cleaning work was completed after the final file was confirmed.

Data cleaning principles: (i) Specify the name of the institution. For different names of the same institution, the currently widely accepted specification name is used. The same institution does not subdivide departments, colleges, divisions, etc. For example, the “School of Chinese Material Medical of Beijing University of Traditional Chinese Medicine,” the “School of Acupuncture and Massage of Beijing University of Traditional Chinese Medicine” and the “First Clinical Medical College of Beijing University of Traditional Chinese Medicine” are unified into the “Beijing University of Traditional Chinese Medicine.” The “Rehabilitation Department of the First Affiliated Hospital of Guangxi University of Traditional Chinese Medicine” and the “Massage Department of the First Affiliated Hospital of Guangxi University of Traditional Chinese Medicine” were unified as the “First Affiliated Hospital of Guangxi University of Traditional Chinese Medicine”; (ii) Merge keywords. For keywords of great significance to the interpretation of the atlas, different expressions of the same meaning are unified into normative terms or common expressions, such as “asthenopia,” “eye fatigue” and “visual fatigue,” which are unified as “asthenopia.”

A keyword co-occurrence map (Figure 6) is generated, and the requencies of keywords (Table 5) are ranked via CiteSpace software. The keywords and their network diagrams succinctly reflect the research topics, which helps identify the hotspots in this field. Among them, higher frequencies indicate more intensive research in the field, whereas higher concentrations indicate the importance of research in the field.

By analyzing the keywords, we can conclude that the high-frequency keywords in English literature are “dry eye syndrome,” “acupuncture,” “myopia,” “randomized controlled trial,” and “system review.” These reflect a focus on evidence-based TCM, comorbidity, and external therapy. High-frequency keywords in the Chinese literature included “dry eye disease,” “acupuncture,” “visual display terminal,” “acupoint massage,” and “auricular acupressure.” These reflect a focus on TCM syndrome differentiation, video terminal-related asthenopia, and acupoint therapy.

In summary, these results can be divided into three categories: eye diseases, TCM prevention and treatment, and research methods.

A keyword clustering map (Figure 7) was generated via CiteSpace software. On the basis of the keyword co-occurrence network, the logarithmic likelihood ratio algorithm was used to obtain the Q-cluster module value and S-cluster contour index value, where Q > 0.3 indicated effective clustering, and the larger the Q-value was, the better the network clustering effect. When S > 0.7, the results of the cluster analysis were valid, and the closer the S-value was to 1, the greater the uniformity of the network. In our study, for English literature, Q = 0.7455 and S = 0.9497. For Chinese literature, q = 0.669, and s = 0.8872. The above values indicated that clustering was meaningful and that the results were reasonable.

Analyze the clustering mapping of keywords in English literature (Figure 7A), the 8 clusters reflect three core research directions. (1) Mechanism exploration: #1 iridoid-polyphenolic fraction (focus on anti-inflammatory/antioxidant effects of herbal components), #7 novel PLGA (drug delivery systems for TCM), #8 reducing accommodative lag (acupuncture’s regulation of ocular accommodation); (2) Comorbidity research: #0 dry eye syndrome, #5 meibomian gland dysfunction, #6 treating dry eye (asthenopia combined with ocular surface diseases); (3) Therapy innovation: #2 low-concentration atropine (combination of TCM and Western medicine), #3 biodegradable microneedle acupuncture (technological upgrade of external therapy); and Research methods: #4 qualitative approach (qualitative analysis of TCM clinical experience).

Analyze the clustering mapping of keywords in Chinese literature (Figure 7B), the 10 clusters reflect three core research directions. (1) TCM intervention application: #2 thunder-fire noxibustion, #3 press-tack needle, #4 acupoint massage, #5 acupuncture and moxibustion (diversified external therapies); (2) Comorbidity research: #0 dry eye disease, #8 viral conjunctivitis (asthenopia combined with common ocular diseases); (3) TCM mechanism research: #7 liver-strain, #9 insufficiency of liver blood (pathogenesis based on TCM zang-fu theory); and Research directions: #6 clinical application, #10 randomized controlled trial (focus on clinical translation of TCM).

A timeline diagram (Figure 8) clearly displays the time range covered by each research hotspot, revealing the connections between different research hotspots, thus revealing the changes in the research hotspots of TCM treatment for asthenopia in the past years. Early stage (2005–2010): The field focused on basic TCM interventions, refractive error, and visual health, with limited mechanistic research. Mid-stage (2011–2018): Research shifted to clinical efficacy verification (e.g., “randomized controlled trial” in both literatures, “acupuncture and moxibustion” as a burst keyword in Chinese literature with intensity = 2.92), and the combination of TCM with modern technology (e.g., “visual display terminal” research). Recent (2019–2024): The focus moved to precision therapy and mechanism exploration (e.g., “biodegradable microneedle acupuncture” in English literature, “liver strain” in Chinese literature with burst intensity = 1.93), reflecting a shift from empirical practice to evidence-based and technologically integrated research.

A visual mapping of keyword bursting (Figure 9) is generated via CiteSpace software. Analyzing the emergence of keywords means identifying words with frequent occurrence and words that have rapidly increased in frequency. The blue line represents the time interval, and the red line represents the time period when the keyword bursts. In our research, keywords with strengths >2 had a significant effect on the development of the research field.

As for English literature (Figure 9A), the most persistent keyword is “refractive error” (2008–2015, burst intensity = 1.54), reflecting early focus on asthenopia’s association with refractive abnormalities. The strongest burst keyword is “systematic review” (2018–2020, intensity = 2.65), indicating a shift to evidence synthesis of TCM efficacy. Recent bursts (2022–2024) includes “biodegradable microneedle acupuncture,” “intradermal acupuncture,” and “meibomian gland massage,” reflecting technological innovation in external therapy and focus on ocular surface microenvironment. The research stage can be divided into three phases. Early phase (2005–2010) focus on basic epidemiological and etiological research, such as “refractive error,” “visual health,” and “ocular surface disease.” Middle phase (2011–2018) focus on clinical intervention verification and evidence synthesis, including “eye exercise,” “systematic review,” “keratoconjunctivitis sicca,” and “acupoint catgut embedding.” Late phase (2019–2024) focus on the combination of TCM and Western medicine, precision external therapy, containing “artificial tear,” “ultrasonic atomization,” “clinical trial,” and “acupuncture therapy.”

As for Chinese literature (Figure 9B), the most persistent keywords are “randomized controlled trial” (2007–2011, intensity = 1.33), and “liver strain” (2020–2024, intensity = 1.93), reflecting long-term focus on clinical evidence and TCM pathogenesis. The strongest burst keyword is “acupuncture and moxibustion” (2011–2012, intensity = 2.92), indicating recognition of external therapy’s core role. Recent bursts (2021–2024) includes “press-tack needle,” “auricular points,” and “data mining”, reflecting precision acupoint therapy and big data-driven TCM research. The research stage can be divided into three phases. Early phase (2005–2010) focus on basic TCM intervention and syndrome differentiation, containing “traditional Chinese medicine,” “thunder-fire moxibustion,” “ziyin runmu tang,” and “muscular asthenopia.” Middle phase (2011–2018) focus on external therapy optimization and video terminal-related asthenopia, containing “acupuncture and moxibustion,” “shugan mingmu tang,” “jingming acupoint,” “visual display terminal.” Late phase (2019–2024) focus on TCM mechanism deepening and comorbidity model research, for “liver strain,” “orthogonal design,” “eye disease,” “data mining.”

The keyword clustering analysis (Figure 7A) identifies #1 iridoid-polyphenolic fraction, #7 novel PLGA, and #8 reducing accommodative lag as core mechanistic themes—directly supported by recent empirical studies:

(1) Iridoid-polyphenolic fraction’s anti-inflammatory effect: Yuan et al. (16) found that iridin (an active component of Belamcanda chinensis, a key source of iridoid-polyphenolic fractions) enhances HCE-2 cell viability and inhibits IL-1β-mediated pyroptosis under hyperosmotic stress, explaining why #1 iridoid-polyphenolic fraction is a core cluster in English literature. This confirms that TCM mechanisms are shifting from macro “liver-kidney regulation” to micro molecular pathways.

(2) Acupuncture’s regulation of ocular accommodation: Chen et al. (17) demonstrated that acupuncture increases dopamine levels in Syrian hamsters via the D1R signaling pathway, suppressing NLRP3 inflammasome activation and reducing accommodative lag, aligning with #8 reducing accommodative lag in English literature. This links TCM’s “meridian unblocking” theory to modern neurobiology, strengthening evidence for acupuncture’s efficacy.

(3) Novel drug delivery systems: The #7 novel PLGA cluster reflects innovations in TCM formulation. For example, Song et al. (18) found that PLGA-based microneedles for sustained acupoint drug release. This addresses TCM’s traditional limitation of poor bioavailability, paving the way for precision external therapy.

These findings confirm that the research on mechanisms is shifting from empirical descriptions to molecular-level verification. This is of vital importance for the promotion of TCM globally and the transformation of its clinical applications.

The keyword clustering (Figure 7B: #2 thunder-fire noxibustion, #3 press-tack needle) and burst analysis (Figure 9B: “acupuncture and moxibustion” intensity = 2.92) highlight external therapy’s evolution toward precision, personalization, and technological integration. This conclusion is also supported by the institutional cooperation network diagram (Figure 5):

(1) Precision acupoint localization: Some core institutions utilize ultrasound and infrared thermal imaging technologies to accurately identify acupoints, with positioning accuracy reaching the sub-millimeter level (19–21). This improves the consistency of treatment and reduces variations among different operators. It solves the problem of “subjective acupoint selection” traditionally and aligns with the minimally invasive and precise stimulation characteristics of #3 press-tack needle cluster.

(2) Technological integration: The keyword “biodegradable microneedle acupuncture” reflects the integration of traditional acupuncture therapy with nanotechnology. For instance, PLGA micro-needles can release herbal extracts such as chrysanthemum flavonoids at the acupuncture points (18). This approach enhances the therapeutic effect through continuous stimulation and improves patient compliance through this painless drug delivery method, thereby addressing the invasiveness issue of traditional acupuncture.

(3) Standardization: The “randomized controlled trial” cluster indicates that progress has been made in establishing operational norms. For instance, the duration of acupuncture has been standardized at 20–30 min, and the frequency is generally controlled at about 3 times per week (22, 23). This is crucial for the promotion of TCM globally, as it reduces the discrepancies when comparing different studies.

However, the English-language research on external therapies is still relatively limited. The existing studies mostly focus on acupuncture, while there is less exploration of other therapies such as massage and cupping. This highlights the necessity of international cooperation to share the diverse external therapy methods of TCM.

Chinese literature keyword clustering (Figure 7B: #7 liver-strain, #9 insufficiency of liver blood) and burst analysis (Figure 9B: “liver strain” intensity = 1.93) confirm that herbal decoction optimization focuses on TCM syndrome differentiation and modern formulation technology. It rooted in classical zang-fu theory, such as “liver stores blood, nourishes the eyes” in Huangdi Neijing.

(1) Syndrome differentiation-based personalization: Core teams classify asthenopia into four types and formulated the following decoctions specifically for each type (24–27). For those with liver-kidney deficiency, Qiju Dihuang Pill is used to nourish essence and improve retinal antioxidant enzyme activity (28); for those with liver qi stagnation, Xiaoyao San is taken to soothe the liver and regulate the blood flow in the ocular arteries (29); for those with weak spleen function, Buzhong Yiqi Decoction is used to enhance the spleen function and improve the microcirculation in the eyes (25); for those with heart-blood deficiency, Tianwang Buxin Dan is taken to nourish the mind and reduce eye fatigue caused by mental stress (26). This is in line with the #7 liver-strain cluster, because the liver qi stagnation caused by mental stress in “liver strain” is a major factor in the modern pathogenesis, which demonstrates the adaptability of TCM to contemporary lifestyles.

(2) Modern formulation innovation: The “orthogonal design” burst keyword reflects using statistical methods to optimize herbal ratios. For example, Liu’s Kangyan Pilao Decoction optimized for anti-inflammatory effects via orthogonal testing of 5 herbs (30). Advanced technologies such as microencapsulation and ultrasonic extraction have further enhanced the bioavailability. For instance, Lycium barbarum polysaccharide microspheres can enhance the protective effect on the retina (31).

(3) Combination with Western medicine: The “artificial tears” burst keyword indicates combining TCM decoctions with Western interventions. For example, using iridin plus artificial tears to improve tear film stability, or using self-made Yanggan Runmu decoction combined with sodium hyaluronate on tear secretion and tear inflammatory factors in patients (32), achieving both symptom relief (Western medicine) and root-cause regulation (TCM). This “integrative model” is supported by the #2 low-concentration atropine cluster, where atropine (myopia control) is combined with acupuncture (asthenopia relief) (33–36).

The “randomized controlled trial” cluster and “systematic review” burst keyword confirm that evidence-based research is a top priority. Core institutions, such as the Ophthalmology Hospital of the Chinese Academy of Traditional Chinese Medicine, are advancing this via three strategies:

(1) Standardized syndrome differentiation: Expert consensus (7) classifies asthenopia into four TCM patterns (liver-kidney deficiency, spleen qi deficiency, heart-blood deficiency, liver qi stagnation), with validated diagnostic criteria, including tongue coating, pulse condition combined with tear film breakup time and so on (37). This addresses traditional TCM’s subjectivity and enables cross-study comparisons.

(2) Modern efficacy metrics: Clinical studies now integrate objective indicators (e.g., serum IL-6/TNF-α levels for inflammation, macular pigment density for retinal health) with TCM symptom scores. For example, Sun et al. (38) used acupuncture plus lutein to increase macular pigment density, quantifying TCM’s “nourish eye” effect via modern imaging.

(3) Data-driven optimization: The “data mining” burst keyword reflects using big data to identify optimal interventions. Wen et al. (39) used association rule mining to confirm that “Jingming BL1 + Taiyang EX-HN5” is the most effective acupoint combination for video terminal-related asthenopia.

The “dry eye disease” cluster and “eye disease” burst keyword highlight asthenopia’s comorbidity with ocular and systemic diseases, which aligns with the “holistic regulation” theory of TCM. The analysis identifies three comorbidity patterns:

(1) Metabolic inflammatory axis comorbidities: Asthenopia patients have higher rates of diabetic retinopathy, linked to elevated oxidative stress (IL-6, TNF-α) (40, 41). TCM’s “Phlegm-Stasis Intermingling” theory explains this, using Danshen (Salvia) and Sanqi (Notoginseng) to regulate lipid metabolism and reduce inflammation (42, 43). This aligns with the #0 dry eye syndrome cluster, as dry eye and diabetes share inflammatory pathways (44).

(2) Neuro-ophthalmic psychosomatic networks: Functional MRI reveals reduced prefrontal-visual cortex connectivity in asthenopia patients, correlating with a 30% higher depression rate (45). TCM uses Anshen Yangxin Formula (Ziziphus-Biota Decoction) to modulate the HPA axis and reduce cortisol levels (37), addressing both ocular fatigue and mental stress. This is consistent with the #7 liver-strain cluster, as “liver qi stagnation” links emotional stress to eye symptoms.

(3) Circadian rhythm-mediated disorders: Dysregulated circadian genes (e.g., CLOCK) reduce tear secretion (46), which aligns with TCM’s “Disordered Defense Qi Circulation” theory, meaning that the vital energy cannot function properly, thereby causing dryness in the eyes (47). Herbal fumigation, like chrysanthemum + peppermint, regulates lacrimal secretion via TRPV1 channels (48), which integrates TCM’s “aroma therapy” with modern circadian biology.