Visual Rehabilitation Through Acoustic Biofeedback With Retimax Vision Trainer in Patients With Advanced Age-related Macular Degeneration

At present there are no real therapies able to improve visual performance in patients with age-related macular degeneration, atrophic type. The aim of the study is to verify whether with rehabilitation sessions with Retimax Vision Trainer it is possible to teach the maculopathic patient to exploit the extrafoveal areas of the retina, not affected by atrophy, resorting to an eccentric vision that compensates for the foveal one, thus obtaining a improvement of visual outcomes (far and near vision capacity, sensitivity to contrast to reading, reading speed, fixation capacity and overall quality of life of the visually impaired patient suffering from atrophic senile maculopathy (AMD)). To do this, the study design was conceived as a non-randomized prospective comparative and involves the formation of two groups of patients: a group A of 15 patients who will be rehabilitated with Retimax and a group B of 15 patients who will not be rehabilitated, but only re-evaluated at the same distance of time that will elapse for group A. Eligible patients are affected by atrophic AMD with unstable fixation and better vision in the eye between 1/10 and 4/10 in the absence of other serious eye diseases. As there is currently no real therapy capable of improving visual performance, the demonstration of the positive effect of the visual rehabilitation program with Retimax in patients suffering from atrophic macular degeneration may encourage a wider use of this method. The patient could benefit from a non-invasive, repeatable and cost-effective procedure.

Study typology:

prospective, non-randomized, monocentric, comparative study. There is no agreement between promoter and clinical center. There is no agreement between promoter and financier: the study has no funding.

Background:

The Retimax Vision Trainer is an innovative method that aims to increase visual function in patients with eye diseases of various origins and nature, allowing the patient to exploit and optimize their residual visual potential. It is aimed at patients with visual impairments of different origins and severity, such as campimetric deficits, low vision of central origin, degenerative retinal diseases, amblyopia.

It consists of a device for recording bioelectrical responses evoked during the perception of structured visual stimuli and the control of the same by the patient through a sound biofeedback mechanism. This results in an increase in visual capacity, exploiting neuronal plasticity through the activation of alternative neuronal circuits. The device has already been used in clinical practice at the AOU Modena for about a year precisely with the indication of rehabilitation in the visually impaired patients: therefore the current indication includes that of the study in question. Subjects with central low vision, such as those with advanced AMD, tend to develop independently an eccentric fixation area (PRL or Preferred Retinal Locus) which is generally found on the horizontal meridian of the fovea, mainly on the interpapillo-macular beam.

However, this situation represents an obstacle because it does not allow a continuous vision, for example preventing reading and writing which would require a strip of healthy retinal tissue long enough to allow the simultaneous viewing of at least 10-12 words.

For this reason patients suffering from central hypovision can benefit from rehabilitative programs with bio-feedback mechanism that teach to move the eye to translate the PRL from the central degenerated area to an adjacent healthy area large enough to allow reading / writing . This leads to the formation of a TRL, Trained Retinal Locus, which is generally found in the upper parafoveal area (projected in the lower part of the visual field to be more functional for daily activities such as, for example, reading).

The most widespread rehabilitation method is stimulation with bio feedback. Each rehabilitation cycle is customized but generally involves twice-a-week sessions in the first five weeks for the creation of the TRL followed by maintenance sessions on a fortnightly basis. At the end of the rehabilitation period it is always advisable to send the patient to the test of the most appropriate aids. Rehabilitation sessions are performed only on the eye with better visual acuity since binocular fixation is determined by the eye with better vision than by the dominant eye.

Purpose:

The purpose of the study is to evaluate the effectiveness of rehabilitation through acoustic biofeedback with Retimax Vision Trainer in patients with low vision suffering from age-related macular degeneration in the advanced phase, in order to demonstrate the positive effect that this treatment has on far and near vision, on the contrast sensitivity, on the reading speed, on the ability to fix and on the overall quality of life of the patient. We will therefore try to highlight the quantitative variation of these parameters between pre and post rehabilitation by comparing two groups of patients, one subjected to rehabilitation and one not and we will try to understand if this variation is significant.

Group A: 15 patients rehabilitated with Retimax Vision Trainer, 10 consecutive sessions of 8 minutes each, performed twice a week in the best eye.

Group B: 15 patients control group without rehabilitation.

Given the need for constancy and collaboration on the part of the patient, these are allocated to the group of treated or to the controls based on the fact that they declare themselves more or less available: patients who have transport problems, who live farther away or who in any case they cannot guarantee their presence twice a week, they are allocated to the control group.

Materials and methods:

Patients will be enrolled during visits to the maculopathy outpatient clinic that follows patients at the end of the cycle for intravitreal injections with anti-VEGF. The enrolled maculopathies are atrophic, therefore in the study there will be both patients with advanced forms of maculopathy who have exhausted the role of anti-VEGF, but also patients with pure atrophic forms who have never performed intravitreal. Therefore, enrollment is independent of the administration of anti-VEGF.

It will be proposed to participate in the study, providing the information sheet and holding an interview explaining the importance of consistency in rehabilitation sessions and what the method consists of. Subsequently consent will be collected. At the signing of the consent, personal data will be collected. The patient will be told that he will be contacted by telephone in the following days to fix the date of the first pre-treatment visit.

Exams performed before and after treatment:

* BCVA (ETDRS)
* Reading speed (MNREAD)
* Contrast sensitivity (Pelli-Robson)
* Microperimetry and analysis of fixation (OCT-SLO OPTOS)
* QoL (VFQ-25)

After the visit, the patient will be contacted by the orthoptists to fix the 10 rehabilitation sessions with Retimax, twice a week. At the end a final post-treatment visit will be repeated, repeating all the exams. At this point we will proceed with statistical analysis, with the help of a biostatisticist, to evaluate the effectiveness of visual rehabilitation.

Statistic analysis The study data are extrapolated from each patient and divided into pre and post-treatment.

The pre-treatment value and the post-treatment value of each single parameter for each individual patient will be compared with each other trying to demonstrate the improvement and the significance of the variation.

For statistical calculations we will use the software R: A language and environment for statistical computing, version 3.3.3, R Foundation for Statistical Computing, Vienna, Austria (http://www.R-project.org/) with the collaboration of a biostatistics expert.

Given the non-normal distribution verified with the Shapiro-Wilk test and the low number, the pre and post treatment values will be compared with the One-sided Wilcoxon Signed Rank Test

Expected results:

* Improvement of fixation capacity and microperimetry
* Improvement of visual acuity, reading speed and contrast sensitivity
* Improvement of sight quality

Eligibility Criteria:
Inclusion Criteria:

Patients were included in the study based on the following criteria:

* Diagnosis of advanced age-related macular degeneration through examination of the fundus oculi and OCT;
* Best corrected visual acuity (BCVA) for far in the best eye between 1/10 and 4/10;
* Collaborating patients with a positive attitude towards a rehabilitation treatment with a bi-weekly commitment.

Exclusion Criteria:

The exclusion criteria from the study are:

* Presence of concomitant retinal or optic nerve pathologies;
* Eye surgery more recent than six months, except for the cataract for which the cut off is fixed at two months;
* Poor collaboration by the patient.