What was the aim of this review?
This review aimed to assess whether acupuncture is useful and safe in treating people with glaucoma. We included in the review three completed trials and one ongoing trial.
What is the key message of this review?
At this time, it is impossible to draw reliable conclusions from available data to support the use of acupuncture for treatment of people with glaucoma.
What was studied in the review?
Glaucoma is a condition that damages the optic nerve and affects visual function. It is a major cause of blindness worldwide. Although many treatments are available, including eye drops, laser treatment, and surgical procedures, some people may seek complementary or alternative medicine approaches such as acupuncture to supplement their regular treatment.
What are the main results of the review?
The three completed studies were conducted in hospitals in Taiwan and the United States. These trials recruited participants with glaucoma or intraocular hypertension (higher than normal eye pressure). The trials differ greatly in the interventions compared, including auricular acupressure (a non-standard acupuncture technique), transcutaneous electrical nerve stimulation, and acupuncture on eye-points (12 sessions). Acupuncture may have a very small effect in reducing eye pressure, but the certainty of evidence is very low. One trial reported needle sensitivity. Trials provided no evidence of effect on visual field or visual acuity.
How up-to-date is this review?
Cochrane Review authors searched for studies that had been published up to November 16, 2018.
At this time, it is impossible to draw reliable conclusions from available data to support the use of acupuncture for treatment of patients with glaucoma. Because of ethical considerations, RCTs comparing acupuncture alone with standard glaucoma treatment or placebo are unlikely to be justified in countries where the standard of care has already been established.
Glaucoma is a multi-factorial optic neuropathy characterized by an acquired loss of retinal ganglion cells at levels beyond normal age-related loss and corresponding atrophy of the optic nerve. Although many treatments are available to manage glaucoma, patients may seek complementary or alternative medicine approaches such as acupuncture to supplement their regular treatment. The underlying plausibility of acupuncture is that disorders related to the flow of Chi (traditional Chinese concept of vital force or energy) can be managed by stimulating relevant points on the body surface.
To assess the effectiveness and safety of acupuncture compared with other treatments, no treatment, or placebo in patients with glaucoma.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register (2018, Issue 11); Ovid MEDLINE; Embase.com; the Cumulative Index to Nursing and Allied Health Literature (CINAHL); the Allied and Complementary Medicine Database (AMED); PubMed; Latin American and Caribbean Literature on Health Sciences (LILACS); ZETOC; the metaRegister of Controlled Trials (mRCT); ClinicalTrials.gov; the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP); and the National Center for Complementary and Alternative Medicine (NCCAM) website. We did not use any language or date restrictions in the search for trials. We last searched electronic databases on November 16, 2018, with the exception of NCCAM, which we last searched on July 14, 2010, and the metaRegister of Controlled Trials (mRCT), which we last searched on January 8, 2013. We handsearched Chinese medical journals at Peking Union Medical College Library in April 2007.
We searched the Chinese Acupuncture Trials Register, the Traditional Chinese Medical Literature Analysis and Retrieval System (TCMLARS), the Chinese Biological Database (CBM), and the China National Knowledge Infrastructure (CNKI). We last searched Chinese electronic databases on November 19, 2018.
We included randomized controlled trials (RCTs) in which one arm involved acupuncture treatment.
Two review authors independently screened results, then extracted the data and assessed risk of bias for eligible trials.
We included three completed trials and one ongoing trial in the 2019 update of this review. The three completed trials, conducted in Taiwan and the United States, included participants with glaucoma or intraocular hypertension. The interventions investigated varied across trials. One trial compared auricular acupressure－a non-standard acupuncture technique－with the sham procedure in 33 patients. Another trial compared transcutaneous electrical nerve stimulation (TENS) with a sham procedure in 82 patients. The third trial compared 12 sessions of acupuncture on eye-points versus on non-eye-points in 22 patients. All three trials were rated at high risk of bias for at least one domain. The certainty of evidence across all outcomes was very low due to high risk of bias in at least one contributing study; substantial clinical heterogeneity and methodological heterogeneity; and imprecision of results.
One trial reported change in the visual field from baseline without any between-group comparison. Because of the quantity of missing data (50%), we did not calculate a between-group comparison, as the quantitative results are difficult to interpret.
All three trials reported data for estimation of reduction of intraocular pressure (IOP). However, time points of IOP measurement varied. For the trial comparing acupressure to a sham procedure, the difference in IOP reduction (measured in mm Hg) is estimated to be -3.70 (95% confidence interval [CI] -7.11 to -0.29) for the right eye and -4.90 (95% CI -8.08 to -1.72) for the left eye at four weeks, and -1.30 mm Hg (95% CI -4.78 to 2.18) for the right eye and -2.30 mm Hg (95% CI -5.73 to 1.13) for the left eye at eight weeks. For the trial comparing TENS to sham treatment, the difference reduction is estimated to be -2.81 (95% CI -3.8 to -1.84) for the right eye and -2.58 (95% CI -3.36 to -1.80) for the left eye immediately after treatment, -2.93 (95% CI -3.72 to -2.13) for the right eye and -3.56 (95% CI -4.35 to 2.78) for the left eye 30 minutes after treatment, and finally -3.61 (95% CI -4.47 to -2.75) for the right eye and -3.61 (95% -4.47 to -2.74) for the left eye. For the trial that compared acupuncture on eye-points versus non-eye-points, 11 out of 22 (50%) participants did not complete the treatment.
One trial reported data for estimation of visual acuity. When acupressure is compared to sham treatment, the difference in uncorrected visual acuity (UCVA, measured in logMAR) is estimated to be -0.01 (95% CI -0.24 to 0.22) for the right eye and -0.04 (95% CI -0.27 to 0.19) for the left eye at four months, and -0.03 logMAR (95% CI -0.27 to 0.21) for the right eye and -0.16 logMAR (95% CI -0.43 to 0.11) for the left eye at eight months. The difference in best corrected visual acuity (BCVA) is estimated to be 0.10 (95% CI -0.06 to 0.26) for the right eye and 0 (95% CI -0.14 to 0.14) for the left eye at four months, and -0.04 logMAR (95% CI -0.09 to 0.17) for the right eye and -0.04 logMAR (95% CI -0.18 to 0.10) for the left eye at eight months.
One trial reported progression of optic disc damage or nerve fiber layer loss without any between-group comparison. Because of the quantity of missing data (50%), we did not calculate a between-group comparison, as the quantitative results are difficult to interpret.
One trial reported adverse events in two patients (out of 22) who experienced needle sensitivity. However, the study did not report between-group comparisons. Because of the quantity of missing data (50%), we did not calculate a between-group comparison, as the quantitative results are difficult to interpret.