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S. Cavarretta, S. Putano, F. Montaldi, S. Salvatore, E. M. Vingolo; Vision Rehabilitation: The Choice of PRL Location by Microperimeter MP1 in Patients With Macular Disease. Invest. Ophthalmol. Vis. Sci. 2007;48(13):3549.
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to evaluate by microperimeter (MP1) the best preferred retinal locus (PRL) location to the rehabilitation in patients with maculopathies.
We enrolled 5 patients, mean age was 53,8, 3 women and 2 men. We examined 9 eyes: 2 vitelliform dystrophy, 1 post traumatic macular scar, 2 Stargardt disease, 2 myopic macular degeneration, 2 cone dystrophy. All patients were subjected to acuity visual exam, reading speed, fluorangiography, ocular coherence tomography, fixation test, microperimetry and biofeedback by MP1. Statistical analysis was performed using t- student test. P values less than 0,05 were considered statistically significant.
At baseline assessment mean best distance spectacle-corrected visual acuity (VA) was 0,79 logMAR, and at the end of visual rehabilitation was 0,3 logMAR. This result was statistically significant. (p= 0,01). The mean value of character size from 11,7 to 7,8 p= 0,03. At the end of visual rehabilitation eyes were divided according to the stability of fixation: 4 eyes were stable fixation and 5 eyes were relatively stable fixation. Fixation behaviour inside the 2 degree diameter circle improved and it was considered statistically relevant according to reading speed (p=0,01). Reading speed improved from a mean value of 64,3 words/minute at the beginning of the study to 92 words/ minute at the end of the protocol (p= 0,04). The increase in the mean retinal sensitivity was considered statistically significant (p= 0,002).
Cerebral plasticity can certainly play an important role, in fact the effect of BFD can be linked to brain ability to perceive an efficient PRL for visual tasks. The audio feedback can in fact help brain to memorize, by an increase of attentional modulation, the final fixation location. Neurons will thus be able to respond to weaker stimuli than they responded to without attention. Attention also increases the coherence between neurons responding to the same stimulus. Sound perception increases conscious attention of the patient thus facilitating the lock- in of the visual target and increasing permanence time of the target itself on the retina. This way stimuli transmission is simpler both between intraretinal neurons and between retina and brain where the highest stimuli elaboration takes place, and we support a "remapping phenomenon".
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