Purpose: To evaluate the effectiveness of biofeedback treatment for low-vision rehabilitation in patients affected by macular disease.
Materials and methods: 171 eyes of 99 patients (42 female and 57 male) between 50 to 75 years old (mean age: 64.6) were included in this study. All patients were suffering from age-related macular degeneration (AMD) (122 eyes) or macular myopic degeneration (MMD) (49 eyes). All patients underwent an assessment of examinations including visual acuity, reading speed test, slit lamp examination and tonometry, ophthalmoscopic fundus examination, microperimetry, fixation test, retinal sensitivity, fluorangiography (FAG), optical coherence tomography (OCT). The treatment was divided in 16 sessions, the patients underwent other examination assessment at 6 and 12 months, except for FAG and OCT. Statistical analysis was performed using Student's t-test, and p-value <=0.05 was considered statistically significant.
Results: After training 130 eyes of 171 in the study group (76.02%) had a statistically significant improvement of the distant visual acuity (p<0.01): 38 eyes suffering from MMD and 92 eyes suffering from AMD. After 12 months of follow-up a group of 25 eyes of 130 (19.23%) had a loss of benefits that were observed at the end of the treatment sessions: 16 eyes and 9 eyes were suffering from MMD and AMD respectively. Examination assessment during follow-up showed that 4 eyes and 2 eyes of the group that lost benefits had a worsening of MMD and AMD primary disease respectively.
Conclusions: It is not yet understood how biofeedback produces amelioration of visual function. According to the 'Eccentric fixation' theory, with biofeedback rehabilitation patients are trained to use the non-damaged retina areas to develop a new preferred retinal locus. In our study group we found a significant improvement in both visual acuity and fixation.