The goal of the proposed research is to test the hypothesis that practicing eye-hand coordination using tablet-computers can improve manual skills of those with Age-related Macular Degeneration (AMD). AMD is an eye disease that causes the loss of sharp central vision used for reading, threading a needle and many other everyday activities. Over 1.7 million Americans over the age of 40 are affected.18 Those with macular degeneration experience a macular scotoma, a blanked-out area of whatever they're attempting to look at and they must use an area of peripheral vision, the Preferred Retinal Locus (PRL) to look at objects of interest. The PRL does not provide sharp vision, causing deficits in eye-hand coordination needed for manual tasks. For example, investigations of the effect of macular scotomas on reach-to-grasp hand movements found slower movements to the object, longer reaction times, and lower hand velocities.1, 20 Another study used a Scanning Laser Ophthalmoscope (SLO) to investigate the effects of scotomas on tracing a complex line pattern (a maze) with the index finger and printing with a pen. The PRL was found to guide the finger in both tasks, but the finger or pen was often in the scotoma and tracing accuracy and printing legibility were very poor compared to normally-sighted subjects.3, 23 There have been few studies of visuo-motor rehabilitation training for deficits caused by macular scotomas. However, a recent study demonstrated that visuo-motor eye movement training improved reading ability of subjects with AMD. 40, 41 In addition, it has been shown that playing action video games can improve certain visual skills.54 Further, computer technologies have been used successfully for visuo-motor rehabilitation of upper extremity paresis caused by stroke. 47, 48. This small but growing body of research suggests that it may be possible to ameliorate manual task deficits caused by AMD through computer-based visuo-motor rehabilitation training. To test this idea, three visuo-motor training modules will be developed for low-cost tablet computers that subjects will use at home. Modules will be for scotoma awareness training, line and circle tracing, and video games. All three modules will involve PRL-hand coordination by moving a stylus on the tablet screen in response to stimuli. Scotoma awareness training is necessary because the majority of those with macular scotomas do not realize they have them. This module will involve moving an object on the screen around with a stylus until another object disappears in the scotoma. The line and circle tracing module will develop eye-hand coordination skills needed for printing. The video game module will include games such as Pong and Pac Man. Playing these games will provide practice in PRL-hand coordination. Progress in PRL-hand coordination will be automatically recorded on the tablet-computer. Changes in manual task performance from the training modules will be assessed using previously developed SLO tests of maze-tracing, and printing. This test will be performed before module training, after completion of each module, and three months after all training. SLO video images showing the hand, stylus, and object on the retina will be measured and analyzed. Several performance measures will be derived from the SLO image analysis including maze-tracing accuracy, printing legibility, retinal area of the stylus, percentage of time the stylus is in the scotoma, and PRL retinal area. This data will be statistically analyzed to determine whether visuo- motor training with the computer tablets improves manual task performance and whether one module is more effective than others.
The proposed research is aimed at developing and testing a new method of visual rehabilitation using inexpensive tablet computers that Veterans with macular degeneration will use at home. Macular degeneration is an eye disease that causes loss of sharp, central vision used to read, thread a needle, and a host of everyday activities. People with macular degeneration have a very difficult time with manual tasks that require eye-hand coordination. By practicing eye-hand coordination games on the computer tablet, it may be possible to improve their manual-task skills. Changes in eye- hand coordination from playing computer-tablet games will be tested with an instrument developed at the Kansas City VAMC that produces video of a person's hand and objects on the eye's light-sensitive retina while the manual task is being done.
