[Purpose]Acupuncture stimulation is known to improve visual acuity. Since this improvement was frequently disassociated with refractive change, we determined the mechanism by examining the patients without lens accommodation.
[Methods]Patients (n = 30) receiving cataract surgery in 2005 at Meiji University of Oriental Medicine Hospital were examined (mean age: 73.0). Bilateral LI4, Taiyang and shang-jingming points were stimulated by acupuncture needles for 10 min (acupoints stimulation). On a different day, the same patients received sham points stimulation at 1 cm above or lateral from the above-mentioned acupoints. Both uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) was measured with a logMAR scale at pre-and post-acupuncture stimulations. Furthermore, the patients with improved UCVA and BCVA typically (n = 4) received topical tropicamide eyedrops for suppression of pupil diameter change. UCVA and BCVA were measured at pre-and post-acupuncture stimulation.
[Results]Acupoints stimulation significantly improved both UCVA (0.39 to 0.30, p < 0.0006) and BCVA (0.15 to 0.08, p < 0.0001). Although sham points stimulation also significantly improved both UCVA (0.38 to 0.32, p < 0.02) and BCVA (0.14 to 0.09, p < 0.0001), there was no significant difference in comparison with acupoints stimulation controls. Under mydriasis after tropicamide eyedrops, acupuncture stimulation did not improved UCVA, and the variation of BCVA was significantly different from control (p < 0.013).
[Discussion]Acupuncture stimulation improved UCVA and BCVA even in elderly patients that lack accommodation. Our results imply that as pupil diameter changes, a subsequent pinhole effect may be a critical mechanism for UCVA and BCVA improvement by acupuncture stimulation. In addition, the phenomena are not specific effects of acupoints and imply a response via sensory nerves.

[Objectives] Acupuncture has shown to be beneficial for pseudomyopia and asthenopia patients through the improvement of hypermyotonia of the masculus ciliaris. Since acupuncture leads to visual acuity improvement and increases the retinal blood-flow volume, we wished to examine whether acupuncture results in higher retinal sensitivity.
[Methods] Eleven healthy adults were recruited for this study. They received acupuncture (leaving needle) of LI4 (Hegu), Taiyang, and shang-jingming on both sides for 10 minutes in the supine position. Ten minutes of supine position with rest was used as a control. Retinal sensitivity before and after acupuncture, was measured using the blue-on-yellow program of the Humphrey Field Analyzer (HFA). The increase of mean deviation parameter (MD), foveal sensitivity, and examination time were analyzed.
[Results] Acupuncture did not influence the MD or foveal sensitivity in this study. However, examination time was significantly prolonged in the control (p< 0.05), but this was suppressed by acupuncture. The number of volunteers with a shorter examination time was significantly larger than the control (p< 0.05).
[Conclusions] A significant improvement in healthy volunteers was not detected by HFA. However, acupuncture may influence both the improvement of asthenopia and the concentration of the volunteers, leading to shortened examination times.