Visuomotor Rehabilitation Training for Manual Task Deficits From Macular Scotomas

The research objective 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 causes the loss of sharp central vision used for reading and many other everyday activities. Those with AMD 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. 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 dramatically improved reading ability of subjects with AMD. In addition, it has been shown that playing action video games can improve certain visual skills. Thus, a 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, two visuo-motor training modules will be developed for low-cost tablet computers that subjects will use at home. Modules will be for, line and circle tracing, and video games. Both modules will involve PRL-hand coordination by moving a stylus on the tablet screen in response to stimuli. Line and circle tracing will develop eye-hand coordination skills needed for printing. The video game module 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 after each training module using previously developed Scanning Laser Ophthalmoscope (SLO) tests of maze-tracing, and printing. The SLO will also be used to determine the position and fixation stability of the subject's PRL and the retinal position of the scotoma. SLO testing will be repeated three months after all training. Digitized 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 other.

There will be six groups of five subjects. Subjects will be assigned as they are recruited to a group until the group is full. Two groups will have training delayed by 6 months and will be tested on the SLO 4 times to assess changes in the dependent measure without training. Following training on each module, subject will be tested on maze tracing and printing in the SLO. Two groups undergo four SLO tests without training and begin training six months later.