Abstract
Purpose:
age related macular degeneration is one of the main cause of visual impairment in elderly people. We studied and compared the efficacy of rehabilitation by means of two different type of biofeedback techniques with MP-1 microperimeter in patients with evoluted AMD.
Methods:
We enrolled 30 patients, mean age 76,38yrs (8,77SD) bilaterally affected by wet AMD. Patients were randomly divided in two groups: A was treated with an acoustic biofeedback, group B was treated with a luminous biofeedback constituted by a black and white checkerboard flickering during the examination. All patients underwent a complete ophthalmological examination including: best distance and near visual acuity assessment, reading speed test, MP-1 microperimetry evaluating BCEA. Low vision rehabilitation consisted in 12 training sessions of 10 minutes for each eye performed once a week with MP-1 for both groups. Statistical analysis was performed using Student’s t- test.
Results:
After training all patients displayed an improvement in visual acuity, fixation behaviuor, retinal sensitivity and reading speed. Group A: visual acuity was not statistically improved (p=0.054), reading speed showed statistically significant improvement (p=0.031), and a statistically significant reduction in average BCEA fixation (p=0.0023) was evidenced and a mean single point retinal sensitivity value was also improved (p=0.044). Group B: visual acuity was statistically higher (p=0.048), reading speed showed statistically significant improvement (p=0.024), a statistically significant high reduction in BCEA (p=0.0012) was evidenced and a mean single point retinal sensitivity value was also improved (p=0.027).
Conclusions:
Our results show that biofeedback techniques can improve fixation stability. Audio feedback and pattern stimulus facilites transmission between intraretinal neurons as well as between the retina and the brain, thereby probably facilitating a remapping phenomenon. Furthermore, highly informative and contrast rich pattern stimulus showed a statistically significant difference towards uninformative plain exercise limited to train the PRL as obtained with older software, thus indicating that it is possible with more informative tasks to reach a wider involvement of cell populations and recruit more and more efficient ganglion cell receptive fields so to better utilize the residual retinal function.
Keywords: 584 low vision •
688 retina •
758 visual fields