Dry eye syndrome (DES) — also called keratoconjunctivitis sicca or tear film dysfunction — affects 5–50% of the adult population depending on the diagnostic criteria used, with prevalence increasing with prolonged use of digital screens, contact lens use, refractive surgery (LASIK), and aging. The standard treatment is instillation of artificial tears (tear substitutes), with additional options including cyclosporine eye drops, lacrimal plugs, and, in severe cases, fibrin sealant or scleral lenses. Despite the availability of these options, many patients remain symptomatic with persistent discomfort, photophobia, and visual blurring that significantly compromise quality of life and productivity. A meta-analysis published in Medicine (Baltimore) in January 2024, pooling 16 RCTs with 1,383 patients, demonstrates that acupuncture combined with artificial tears offers superior results to artificial tears alone across all objective parameters of tear film evaluation.
The study was conducted by Wang and colleagues, with searches in multiple databases including PubMed, Cochrane Library, Embase, CNKI, and Wanfang. The inclusion of Chinese databases is methodologically important, since China concentrates a large portion of clinical research on acupuncture for ophthalmologic conditions. Only RCTs with artificial tear control (reflecting the current treatment standard), objective outcomes documented by calibrated ophthalmologic instruments, and adequate randomization were included. The 16 RCTs covered a total of 1,383 patients with confirmed diagnosis of dry eye syndrome, majority women (DES is more prevalent in females, especially in the postmenopausal period).
PARAMETERS EVALUATED IN THE ACUPUNCTURE FOR DRY EYE META-ANALYSIS (MEDICINE BALTIMORE, JAN 2024)
Why Are Objective Parameters Crucial?
Dry eye syndrome has a challenging diagnostic aspect: symptoms reported by patients (burning, foreign body sensation, paradoxical tearing) frequently do not correlate well with objective parameters. This symptom-sign dissociation is well known and makes clinical trials more difficult to interpret. The three objective parameters evaluated in this meta-analysis are the most used in ophthalmologic practice: BUT (tear film break-up time) measures the stability of the tear film after blinking — values below 10 seconds indicate pathologic instability; the Schirmer I Test assesses basal tear production — values below 10 mm in 5 minutes indicate hyposecretion; and corneal fluorescein staining identifies areas of corneal epithelium damaged by exposure to dryness.
The fact that acupuncture demonstrates significant improvement on these three objective markers — not only on subjective symptoms, which would be susceptible to placebo effect — is the most robust datum from this meta-analysis. The Schirmer improvement indicates effect on tear production (possibly via modulation of the lacrimal nerve, branch of the trigeminal); the BUT improvement suggests stabilization of the lipid layer of the tear film (produced by Meibomian glands); and reduction of corneal staining indicates less epithelial damage — the final result of a more stable tear film.
Acupoint Protocols and Treatment Frequency
The included RCTs used predominantly periocular acupoints: BL-1 (Jingming, near the medial canthus of the eye), BL-2 (Zanzhu, at the medial extremity of the eyebrow), GB-1 (Tongziliao, at the lateral canthus of the eye), and ST-1 (Chengqi, below the pupil). These acupoints have direct anatomic proximity with lacrimal structures and with the trigeminal nerve branches that innervate them. Complementary distal acupoints frequently used include ST-36 (Zusanli), SP-6 (Sanyinjiao), and KI-3 (Taixi), which contribute to systemic regulation of the neuroendocrine axis and to treatment of patterns of liver/kidney yin deficiency — a TCM diagnostic pattern frequently associated with DES in peri- and postmenopausal women.
The most common frequency in the RCTs was 3 weekly sessions for 4–8 weeks, with some protocols using up to 5 weekly sessions in the initial phase. The minimum treatment duration appears to be 4 weeks for measurable effect on objective parameters. A previous meta-analysis (2023) that evaluated dose-response in acupuncture for DES identified as the optimal protocol: insertion at 4 specific acupoints for 21–30 days at a frequency of 2–3 weekly sessions — suggesting that continuity of treatment for at least 3–4 weeks is necessary for consistent results.
Frequently Asked Questions
Yes, when performed by a trained medical acupuncturist. The periocular acupoints BL-1, BL-2, GB-1, and ST-1 are part of the standard curriculum of medical acupuncture training, with precise insertion techniques and defined depths to avoid vascular structures and the eyeball. In practice, these points are widely used and well tolerated. The recommendation is that the patient keep the eyes closed during the procedure and immediately report any unusual sensation. The risk of ocular complications with adequate technique is extremely low.
There is clinical plausibility for this scenario — contact lens use induces DES through multiple mechanisms (reduced corneal sensitivity, altered lipid layer, limbal hypoxia). The RCTs in this meta-analysis did not report specific subgroups by etiology, but the mechanisms by which acupuncture improves the tear film (neural modulation, glandular effect) are independent of underlying etiology. In lens users with persistent DES, acupuncture may be tried while keeping the lenses out during the treatment period and the hours following each session.
This meta-analysis did not systematically assess the durability of effects beyond the active treatment period. In clinical practice, patients with chronic DES (which is the rule, not the exception) typically need maintenance sessions — frequency is individualized but tends to be monthly after the intensive phase. DES associated with autoimmune conditions (Sjogren’s) or permanent structural conditions (post-LASIK) tends to require continuous maintenance; situational DES (excessive screen use, occupational dry eye) may respond with periodic treatments.
Fonte Original
Medicine (Baltimore)(em inglês)Founded in 1989 by physicians trained at the University of São Paulo (USP) and specialized in China, CEIMEC is a Brazilian national reference in the teaching and practice of medical acupuncture. With more than 3,000 physicians trained over 35 years, it collaborates with HC-FMUSP and is recognized by the Brazilian Medical College of Acupuncture (CMBA/AMB).