Acupuncture may be an effective alternate treatment to occlusion therapy when treating children with anisometropic amblyopia, suggests a study in the December 2010 issue of Archives of Ophthalmology.
Between December 2007 and May 2009 , Dr. Jianhao Zhao and colleagues from Shantou University, Guangdong, China, and the Chinese University of Hong Kong conducted a randomized, controlled trial in which they compared acupuncture and patching in 88 children aged 7-12 years who had anisometropic amblyopia and had worn spectacles for at least 16 weeks prior to enrollment (Arch. Ophthalmol. 2010;128:1510-7).
Patients received either 2 continuous hours of patching a day or five acupuncture treatments per week. The researchers instructed the patching group to perform near-vision activities for 1 hour during patching and the acupuncture group to perform 1 hour of near vision activities daily. For the latter group, the researchers chose five acupoints based on theory and recent literature of traditional Chinese medicine
Follow-up visits were scheduled at weeks 5, 10, 15, and 25. Best spectacle-corrected visual acuity (BSCVA) in the amblyopic eye at week 15 was the main outcome measure.
At 15 weeks, the researchers gathered data from 42 participants in the patching group and 41 in the acupuncture group. In the patching group, mean BSCVA improved from 0.49 logMAR (minimum angle of resolution) at baseline to 0.30 logMAR, with a mean improvement of 1.83 lines. In the acupuncture group, mean BSCVA improved from 0.46 logMAR at baseline to 0.23 logMAR, with a mean improvement of 2.27 lines, a significant difference between the groups of (P =. 03). Twenty-eight participants (66.7%) in the patching group and 31 (75.6%) in the acupuncture group experienced at least two lines of improved visual acuity. The amblyopia was considered resolved in 7 participants (16.7%) in the patching group and 17 (41.5%) in the acupuncture group.
By 25 weeks, BSCVA was 0.28 logMAR in the patching group and 0.22 logMAR in the acupuncture group. BSCVA in the amblyopic eye improved significantly every 5 weeks, except for week 25. Between the 15th and 25th weeks, eight patients (19%) in the patching group and seven (17%) in the acupuncture group had at least one additional line of improved visual acuity.
Although acupuncture has been used to treat amblyopia, the researchers believe this is the first randomized, clinical trial to compare its effectiveness to patching. However, they say the reasons for its success in treating amblyopia are unclear.
"Acupuncture at vision-related acupoints may modulate the activity of the visual cortex," they wrote. "Moreover, acupuncture has been shown to be effective in increasing blood flow to the cerebral and ocular vasculatures (including the choroid), stimulating the expression of retinal nerve growth factors and leading to metabolic changes in the central nervous system. In amblyopia, microscopic anatomical and structural abnormalities have been found in the retina, lateral geniculate bodies, and visual cortex."
Although the findings of this study suggest that acupuncture is as effective as patching for treating amblyopia, the researchers caution that additional multicenter studies on different types of amblyopia and with a longer follow-up period are necessary. The five acupuncture points used were located around the eye ridges, the top of the head, by the base of the thumb, and on the side of the upper ankle.
Several of the authors have filed a provisional patent application for the stimulation of specific acupuncture points for the improvement of vision with the U.S. Patent and Trademark Office. This study was supported in part by the Mr. Lai Seung Hung and Mrs. Lai Chan Pui Ngong Eye Fund (Hong Kong) and the Edith C. Blum Foundation (New York).