Eyeworld

EW NEWS & OPINION 32 October 2016 were tested again. "What we saw was an additional 1.2 letters on aver- age," he said, adding that these were healthy young adults ages 18 to 35. In one case there was a pa- tient who came in with extremely good vision already. "One person had 8/20 vision—just amazing," Dr. Woodman said. "That person showed no improvement with the brain stimulation. It doesn't get much better." The patient may be operating at the limits of the optics. "The lenses can't do much better than that projecting onto the reti- na," he said. However, when it came to those with poor vision, the opposite was true. "The subjects with the worst vision showed the biggest improve- ment," Dr. Woodman said, adding that this is particularly intriguing since these were healthy young adults. It would be interesting to see if this trend generalizes to those with true clinical grade vision defi- cits, he noted. "If it's the case that the worse a person is as a healthy young adult, the bigger the bang of this stimulation, then a patient with early-stage glaucoma might see a huge improvement relative to the average 1.2 letters in the Snellen eye chart that we saw," Dr. Woodman said, adding that they are hoping to try the approach in glaucoma and with other disorders. The fact that the effects of the stimulation were immediate should not be overlooked, Dr. Woodman pointed out. "It doesn't look like it's a learning effect," he said. "It looks like the volume is turned up on it like the visual system is responding more vigorously to visual stimuli immediately after the stimulation." Investigators found that this effect was significantly different for about 90 minutes following the stimula- tion. In related experiments stim- ulating other parts of the brain, investigators determined that effects lasted up to 5 hours. "Some of what we want to do in the near future is to see whether we can have these effects last longer," he said. The hope is if this is done daily, there could be some cumulative effect, or if the technique was altered some- what, the effect might be longer. The ultimate goal would be to see permanent improvement in how the visual system responds, Dr. Woodman said. by Maxine Lipner EyeWorld Senior Contributing Writer Those who wore corrective lenses normally were able to use them for the study. The brain stimulation ran for 20 minutes and then patients visual cortex, the subjects under- went visual acuity testing. "We gave the Snellen eye chart and got a base- line for them," Dr. Woodman said. Boosting the brain's visual cortex T reating the eyes themselves may not be the only way to enhance vision—the brain can be a possible target, according to Geoffrey Woodman, PhD, associate professor, Vanderbilt University, Nashville, Tennessee. Investigators have found that by stimulating the brain's visual cortex for about 20 minutes, acuity can be improved for 1.5 hours. Such were the results that were recently published in Current Biology. Stimulating start In the study, investigators wanted to determine if they could improve vision using noninvasive direct- current stimulation. To accomplish this, a contact was first made on the top of the head using a wet sponge, while the other was placed on the cheek to complete the circuit, Dr. Woodman said. Before running the 2 microamps of current through the Charging up acuity

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