Computerized evaluation of deambulatory pattern before and after visual rehabilitation treatment performed with biofeedback in visually impaired patients suffering from macular degeneration

Abstract

Aims: The aim of this study was double: the primary endpoint was to evaluate the efficacy of visual rehabilitation of visually
impaired patients with macular degeneration (AMD). The secondary endpoint was to assess the effect of rehabilitation treatment
on the ambulatory pattern using a computerized evaluation of walking, focusing the attention on space-time parameters that are
influenced in patients with visual impairment.
Methods: 10 patients with AMD were enrolled, 6 males and 4 females, and examined 15 eyes, at Department of Sense Organs,
Faculty of Medicine and Dentistry Sapienza University of Rome, Italy.
Visual rehabilitation was carried out with the use of a microperimeter MP1 using the examination of biofeedback. Patients are
asked to move their eyes in coordination with an audible feedback that alerts the patient when he is setting properly the fixation
target previously selected. All patients were subjected to 10 sessions lasting 15 minutes each for each eye, 1 time per week. The best
corrected visual acuity (BCVA) was assessed by far with the ETDRS optotype IN LOG MAR, and by close to 25 cm by adding + 4
ball (addition to near) to the BCVA. For each eye the PB ( print body) on the distance of 25 cm was measured; It fixation stability
for 30 seconds was examined by microperimeter. Gait Analysis was performed with system ELITE BTS SpA (Milan, Italy).
Results: At the end of the rehabilitation treatment with biofeedback it was found a marked improvement in BCVA. The BCVA
before the rehabilitation treatment was ETDRS 12 LETTERS = 0.86 logMAR. At the end of the visual rehabilitation 16
LETTERS = 0.78 logMAR. The near visual acuity presented a decrease of the printer body measurement (PB) and a statistically
significant improvement in the fixation stability.
Analysis of the spatial and temporal parameters of gait cycle, aimed at assessing the global aspects of gait (speed, rhythm, symmetry,
fluidity, dynamic balance) showed no significant changes after the treatment, indicating that the previously structured locomotor
pattern was not modified.
Conclusions: The results obtained by the visual rehabilitation with Biofeedback show a pronounced and statistically significant
improvement in visual performance. In fact, the absolute values of retinal sensitivity before and after the visual rehabilitation cycle
with biofeedback showed a marked improvement of the specific retinal sensitivity and consequently an improvement of the vision
efficiency. Further studies are needed to better understand the "correlation" between low-vision and walking.