MP-1 biofeedback: luminous pattern stimulus versus acoustic biofeedback in age related macular degeneration (AMD)

Biofeedback rehabilitation in patients with binocular inhibition due to macular disease

BACKGROUND

To investigate whether patients with binocular reading inhibition due to central vision loss benefit from a new biofeedback (BF) rehabilitation method that aimed at improving fixation stability and at establishing a correspondence between the monocular preferred retinal loci (PRLs) on functioning retina in both eyes.

METHODS

Thirty-three patients with bilateral macular disease and with binocular reading inhibition participated in 10 training sessions consisting of 10-min visual stimulation for each eye to stabilize fixation and relocate the PRL (if needed) using the BF module of the MP-1 microperimeter (Nidek Technologies Srl., Vigonza, PD, Italy). Binocular and monocular reading performance, contrast sensitivity, and visual acuity were evaluated pre and post training. Binocular summation/inhibition was evaluated with binocular ratio (BR).

RESULTS

Fixation stability improved significantly post training in both eyes. Maximum reading speed during binocular viewing increased from 57 ± 24wpm pre training to 67 ± 24wpm post training. BR increased for all parameters of reading, visual acuity, and contrast sensitivity. Training resulted in a complete reversal of binocular reading inhibition in 30% of patients.

CONCLUSIONS

For patients with binocular inhibition due to central vision loss, BF training to stabilize fixation and to bring the monocular PRLs into correspondence on functioning retina in both eyes is an efficient rehabilitation method to improve binocular performance.

Fractal Phototherapy in Maximizing Retina and Brain Plasticity

The neuroplasticity potential is reduced with aging and impairs during neurodegenerative diseases and brain and visual system injuries. This limits the brain's capacity to repair the structure and dynamics of its activity after lesions. Maximization of neuroplasticity is necessary to provide the maximal CNS response to therapeutic intervention and adaptive reorganization of neuronal networks in patients with degenerative pathology and traumatic injury to restore the functional activity of the brain and retina.Considering the fractal geometry and dynamics of the healthy brain and the loss of fractality in neurodegenerative pathology, we suggest that the application of self-similar visual signals with a fractal temporal structure in the stimulation therapy can reactivate the adaptive neuroplasticity and enhance the effectiveness of neurorehabilitation. This proposition was tested in the recent studies. Patients with glaucoma had a statistically significant positive effect of fractal photic therapy on light sensitivity and the perimetric MD index, which shows that methods of fractal stimulation can be a novel nonpharmacological approach to neuroprotective therapy and neurorehabilitation. In healthy rabbits, it was demonstrated that a long-term course of photostimulation with fractal signals does not harm the electroretinogram (ERG) and retina structure. Rabbits with modeled retinal atrophy showed better dynamics of the ERG restoration during daily stimulation therapy for a week in comparison with the controls. Positive changes in the retinal function can indirectly suggest the activation of its adaptive plasticity and the high potential of stimulation therapy with fractal visual stimuli in a nonpharmacological neurorehabilitation, which requires further study.

The Effect of Varied Microperimetric Biofeedback Training in Central Vision Loss: A Randomized Trial

SIGNIFICANCE

This investigation reports for the first time the effects of different microperimetric biofeedback strategies in visually impaired subjects with central field loss.

PURPOSE

This study aimed to evaluate the effects of two MP-3 microperimeter biofeedback strategies on the visual performance of subjects with central vision loss. Moreover, changes between the groups were compared to provide indications of practice with biofeedback stimulation in subjects with central vision loss.

METHODS

Using simple randomization, 19 participants were trained according to two different biofeedback stimulation approaches using the MP-3 microperimeter. Patients were assigned to two different groups: subjects trained for 2 days a week (group A) and 3 days a week (group B). The patients in each group were randomized to perform a total of 10 or 15 sessions.

RESULTS

Fixation stability increased from 4.5 ± 2.8 to 2.3 ± 2.2° 2 and from 8.2 ± 6.9 to 1.4 ± 1° 2 after 2 and 3 weekly biofeedback training sessions, respectively ( P < .05). Biofeedback training induced a significant improvement of 40.7 and 29.4% in reading speed for groups A and B, respectively ( P < .05). A comparison of two weekly biofeedback training sessions with three weekly biofeedback sessions demonstrated greater fixation stability in group B ( P < .05).

CONCLUSIONS

This study concludes that a biofeedback intervention is effective in enhancing oculomotor control in patients with central vision loss. In our study, a more intensive biofeedback strategy seemed to produce significantly better results in terms of functional vision parameters.

Biofeedback Training after Successful Inverted Internal Limiting Membrane (ILM)-Flap Technique for High Myopic Macular Hole

BACKGROUND

Microperimetric biofeedback training improved visual acuity and fixation stability in patients who previously underwent macular surgery. We aimed to compare the functional results of biofeedback training with the standard of care in patients who underwent successful inverted Internal Limiting Membrane (ILM)-flap technique for high myopic macular holes (hMMH).

METHODS

This was a retrospective, comparative, cohort study. Patients with hMMH after surgical hole closure underwent microperimetric biofeedback using structured light stimulus plus acoustic tone (n = 12; Biofeedback) or standard of care with scheduled visits (n = 11; Control). Best-corrected visual acuity, retinal sensitivity at central 12° (RS) and 4° (CRS) with a mean deviation at central 12° (MD), and fixation stability as bivariate contour ellipse area (BCEA 68%, 95%, and 99%) were assessed at baseline and month 1, 3, 6, and 12. The Mann-Whitney test was used to test the difference between the groups.

RESULTS

Baseline functional parameters were not significantly different among the groups. BCVA significantly improved in each group (Biofeedback, p = 0.002; Control, p ≤ 0.02) at all follow-up visits. CRS significantly improved at 6 (p = 0.03) and 12 (p = 0.01) months in the Biofeedback group and at month 12 (p = 0.01) in the Control group. RS (p = 0.001) and MD (p = 0.005) improved at the last follow-up only in the trained group. After training, BCEA 68% and 95% significantly improved (6 and 12 months, p < 0.05). The Biofeedback group had better results in RS (p ≤ 0.02), CRS (p ≤ 0.02), and BCEA 68%, 95%, and 99% (p ≤ 0.01) compared to the Control at all follow-ups. BCVA and MD were better in the Biofeedback group at month 3 (p = 0.01), and month 3 (p = 0.01) and 12 (p = 0.003), respectively.

CONCLUSIONS

Microperimetric biofeedback can increase retinal sensitivity and stabilize fixation better than the standard care over months after a successful inverted ILM-flap for hMMH.

Visuo-Acoustic Stimulation's Role in Synaptic Plasticity: A Review of the Literature

Brain plasticity is the capacity of cerebral neurons to change, structurally and functionally, in response to experiences. This is an essential property underlying the maturation of sensory functions, learning and memory processes, and brain repair in response to the occurrence of diseases and trauma. In this field, the visual system emerges as a paradigmatic research model, both for basic research studies and for translational investigations. The auditory system remains capable of reorganizing itself in response to different auditory stimulations or sensory organ modification. Acoustic biofeedback training can be an effective way to train patients with the central scotoma, who have poor fixation stability and poor visual acuity, in order to bring fixation on an eccentrical and healthy area of the retina: a pseudofovea. This review article is focused on the cellular and molecular mechanisms underlying retinal sensitivity changes and visual and auditory system plasticity.

An Overview of Preferred Retinal Locus and Its Application in Biofeedback Training for Low-Vision Rehabilitation

Central vision loss (CVL) caused by macular damage generally disables common daily tasks, which cannot be reversed by present treatments. Fortunately, it has been found that biofeedback training by inducing or reinforcing preferred retinal locus (PRL) as an eccentric fixation reference contributes to the improvement of visual performance in patients with CVL. However, the clinical application is still under controversy due to poor knowledge of its fundamental and inconsistent practical standards. This article aims to summarize the possible rationale for the development, location, re-location and evaluating indicators of PRL, and the general apparatus, protocol, and outcome of biofeedback PRL training.

Fundus-controlled perimetry (microperimetry): Application as outcome measure in clinical trials

Fundus-controlled perimetry (FCP, also called 'microperimetry') allows for spatially-resolved mapping of visual sensitivity and measurement of fixation stability, both in clinical practice as well as research. The accurate spatial characterization of visual function enabled by FCP can provide insightful information about disease severity and progression not reflected by best-corrected visual acuity in a large range of disorders. This is especially important for monitoring of retinal diseases that initially spare the central retina in earlier disease stages. Improved intra- and inter-session retest-variability through fundus-tracking and precise point-wise follow-up examinations even in patients with unstable fixation represent key advantages of these technique. The design of disease-specific test patterns and protocols reduces the burden of extensive and time-consuming FCP testing, permitting a more meaningful and focused application. Recent developments also allow for photoreceptor-specific testing through implementation of dark-adapted chromatic and photopic testing. A detailed understanding of the variety of available devices and test settings is a key prerequisite for the design and optimization of FCP protocols in future natural history studies and clinical trials. Accordingly, this review describes the theoretical and technical background of FCP, its prior application in clinical and research settings, data that qualify the application of FCP as an outcome measure in clinical trials as well as ongoing and future developments.

Characteristics of Preferred Retinal Locus in Eyes with Central Vision Loss Secondary to Different Macular Lesions

OBJECTIVE

Preferred retinal locus (PRL) training has been applied to low-vision rehabilitation for patients with central vision loss (CVL). This study aimed to explore the characteristics of a natural PRL in eyes with different macular lesions. The data may be useful in customizing training programs.

METHODS

A total of 72 eyes with CVL were included and assigned into two groups. In group A, 29 eyes diagnosed with macular holes featured relatively sharp borders and small areas of lesions. In group B, 44 eyes showed lesions characterized by irregular borders and large areas. The PRL location relative to a scotoma in the retina, fixation stability, and the average threshold surrounding the PRL were determined and compared between the two groups.

RESULTS

In group A, the PRL was located above in 48.28%, below in 27.59%, left in 62.07%, right in 31.03%, and inside in 3.45% of the eyes. In group B, the PRL was located above in 39.53%, below in 4.65%, left in 44.19%, right in 6.98%, and inside in 27.91% of eyes. The amount of retinal displacement occurring within 1° from an initial reference point (P< .05) and the 95% bivariate contour ellipse area (P< .05) in group A were respectively higher and lower than those in group B. However, the average thresholds around the PRLs in the two groups showed no significant difference (P > .05).

CONCLUSIONS

A PRL to the left of or above a scotoma tends to develop to avoid the right and inferior field defect, regardless of the scale and boundary of lesions. Although light sensitivity around a PRL shows no relation to lesion features, fixation stability is worse in irregular and large lesions.

Biofeedback stimulation in the visually impaired: a systematic review of literature

BACKGROUND

It is estimated that approximately 1.3 billion people live with some form of distance or near visual impairment. Numerous studies have been carried out to evaluate the effects of biofeedback (BF) and establish if it could be a useful tool in vision rehabilitation for various eye diseases.

OBJECTIVE

This systematic review aimed: 1) to examine the current evidence of BF efficacy for the rehabilitation of the visually impaired and 2) to describe methodological variations used in previous BF studies to provide recommendations for vision rehabilitation interventions.

METHODS

A systematic review was conducted in the Medline, PubMed, Cochrane Library and Web of Science databases to collect documents published between January 2000 and May 2020. Of the 1,960 studies identified, 43 met the criteria for inclusion. The following information was collected from each study: sample size, control group, any eye disease, apparatus used, frequency and number of sessions of BF, main outcomes of training and whether a follow-up was conducted. The first group included studies published as scientific articles in peer-reviewed journals. The second group included abstracts of studies presented at peer-reviewed conferences. Publications were also grouped according to the eye disease treated.

RESULTS

25 articles and 18 peer-reviewed conference abstracts (PRCAs) were included in this review. BF stimulation is a commonly used technique for the treatment of visual impairment caused by macular disease. Most BF studies evaluate the effect of training on the preferred retinal locus (PRL), particularly with regard to fixation location and stability. Across these studies, participants who received BF intervention improved fixation stability and reading speed. High variability in the number of sessions and the duration of BF training was found. Most studies did not use a control group.

CONCLUSIONS

The findings of this review present evidence for biofeedback treatment in vision rehabilitation, with improved oculomotor abilities. Currently, it is not possible to formulate evidence-based recommendations for a standard training procedure due to the poor quality of existing randomised controlled trials. High-quality studies are needed to develop standard protocols for a range of eye diseases.

Efficacy of biofeedback rehabilitation based on visual evoked potentials analysis in patients with advanced age-related macular degeneration

Age-related macular degeneration (AMD) is a progressive and degenerative disorder of the macula. In advanced stages, it is characterized by the formation of areas of geographic atrophy or fibrous scars in the central macula, which determines irreversible loss of central vision. These patients can benefit from visual rehabilitation programmes with acoustic “biofeedback” mechanisms that can instruct the patient to move fixation from the central degenerated macular area to an adjacent healthy area, with a reorganization of the primary visual cortex. In this prospective, comparative, non-randomized study we evaluated the efficacy of visual rehabilitation with an innovative acoustic biofeedback training system based on visual evoked potentials (VEP) real-time examination (Retimax Vision Trainer, CSO, Florence), in a series of patients with advanced AMD compared to a control group. Patients undergoing training were subjected to ten consecutive visual training sessions of 10 min each, performed twice a week. Patients in the control group did not receive any training. VEP biofeedback rehabilitation seems to improve visual acuity, reading performances, contrast sensitivity, retinal fixation and sensitivity and quality of life in AMD patients.

Effect of Background Brightness on Preferred Retinal Loci in Patients With Macular Disease

Purpose

To evaluate the effect of background brightness on the preferred retinal locus (PRL) in patients with macular disease.

Methods

The study included 27 eyes (27 patients) with macular disease. Microperimetry (MP) was performed to evaluate the PRL and retinal sensitivity (RS) at 10 cd/m². A prototypical device was used to evaluate the PRL at 650 cd/m². Patients were divided into two groups: central fixation (CF) and eccentric fixation (EF).

Results

The PRLs under different brightness levels differed significantly (P < 0.001) in 15 of 27 eyes (two of 13 eyes in the CF group and 13 of 14 eyes in the EF group). The best-corrected visual acuities (BCVAs) in eyes with different PRLs were significantly worse (P = 0.019) than in eyes with one PRL, although the foveal RS did not differ significantly. In patients with BCVAs over 0.1, the PRLs differed in four of 13 eyes in the CF group and in three of four eyes in the EF group (P > 0.05); in patients with BCVAs of 0.1 or lower, the PRLs differed in one of four eyes and 10 of 10 eyes, respectively (P = 0.011).

Conclusions

In patients with macular disease, PRLs can change depending on the surrounding brightness. It may be beneficial to evaluate PRLs under brighter background conditions (e.g., in ambient light) when performing visual rehabilitation for these patients.

Translational Relevance

This study provides important information for visual rehabilitation of patients with macular disease.

Biofeedback Low Vision Rehabilitation with Retimax Vision Trainer in Patients with Advanced Age-related Macular Degeneration: A Pilot Study

PURPOSE

To evaluate the effectiveness of Visual Evoked Potential (VEP) biofeedback rehabilitation in selected low vision patients with advanced age-related macular degeneration (AMD).

DESIGN

Retrospective observational cohort study.

METHODS

Patients affected by advanced AMD, central macular atrophy with unstable fixation and best corrected visual acuity (BCVA) between 20/100 and 20/320 were considered. Selected patients underwent fundus photography and microperimetry with fixation analysis for the selected eye (highest BCVA). Ten consecutive training sessions of 10 min each were performed twice a week in the selected eye with Retimax Vision Trainer (CSO, Florence). BCVA, reading acuity and reading speed, contrast sensitivity, fixation, retinal sensitivity and quality of life questionnaire (VFQ-25) were evaluated at baseline and 7 days following the final session.

RESULTS

Significant improvements in terms of BCVA [p = .011], reading speed [p = .007], VFQ-25 score [p = .007], retinal sensitivity [p = .021] and fixation stability in the central 2° and 4° [p = .048; p = .037] post-treatment were observed for the 9 patients enrolled, with insignificant improvements observed in reading acuity and contrast sensitivity [p = .335; p = .291].

CONCLUSIONS

Preliminary results support VEP biofeedback rehabilitation improvements for visual function and quality of life in advanced AMD patients with low vision.

Preliminary Findings on the Optimization of Visual Performance in Patients with Age-Related Macular Degeneration Using Biofeedback Training

Biofeedback training has been used to improve fixation stability in subjects with central vision loss, but the psychophysiological mechanisms underlying the functional improvements resulted was not reported. The aim of this study was to investigate the effects of microperimetric biofeedback training on different visual functions and self-reported quality of vision in subjects with age-related macular degeneration. This case-control study included six subjects (72.0 ± 6.1 years of age) diagnosed with age-related macular degeneration (wet or dry) with low vision (best corrected visual acuity ranging from 0.5 to 0.1 in the study eye) and five healthy volunteers (64.2 ± 3.7 years of age). Ophthalmological and functional examinations were obtained from all subjects twice with an approximately 3-month interval. Subjects with central vision loss performed 12 sessions (10 min each) of biofeedback training between the two examinations. Functional evaluation included: microperimetry, spatial luminance contrast sensitivities, color vision thresholds, visual acuity, and reading speed. Visual performance during daily activities was also assessed using a standardized questionnaire. The ratio (2nd/1st examination) of the spatial luminance contrast sensitivity at lower spatial frequencies were much higher for the training subjects compared with the controls. In addition, self-reported quality of vision improved after the training. The significant improvement of the visual function such as spatial luminance contrast sensitivity may explain the better self-reported quality of vision. Possible structural and physiological mechanisms underlying this neuromodulation are discussed.

Microperimetric Biofeedback Training after Successful Inverted Flap Technique for Large Macular Hole

Background: Despite the high closure rate of large macular hole (LMH) after surgery, visual recovery is often worse than expected. Microperimetric biofeedback can improve visual function in macular pathologies. We evaluated the efficacy of biofeedback on macular function after successful inverted flap technique for LMH. Methods: In this prospective comparative study, 26 patients after LMH surgical closure were enrolled. The whole sample was equally divided into two groups. In Group 1 (trained), patients underwent a double cycle of microperimetric biofeedback, using structured light stimulus plus acoustic tone; in Group 2 (control), patients underwent scheduled visits. We analyzed visual acuity, retinal sensitivity at central 12° (macular sensitivity, MS) and 4° (central macular sensitivity, CMS), and fixation stability over twelve months. Results: Visual acuity improved mainly in the trained group, without any significant differences between the groups (p > 0.05). Only after training did MS significantly improve (p = 0.01). CMS more significantly improved in the trained (p < 0.001) than the control group (p < 0.01) (Group 1 vs. 2, p = 0.004). Only in the trained group did fixation significantly improve (3 months, p ≤ 0.03; 12 months, p ≤ 0.01). An equality test on matched data confirmed a greater significant improvement of CMS (p ≤ 0.02) at all follow-up and fixation (p ≤ 0.02) at last follow-up after training. Conclusions: Microperimetric biofeedback consolidates and increases the improvement of retinal sensitivity and fixation gained after successful inverted flap technique.

Patient-reported outcomes in randomised controlled trials on age-related macular degeneration

BACKGROUND/AIMS

The purpose of this systematic review was to identify the frequency and type of patient-reported outcome measures (PROMs) used in recent randomised controlled trials (RCTs) for age-related macular degeneration (AMD).

METHODS

The authors conducted a systematic search between January 2010 and November 2013 in MEDLINE, EMBASE, Scopus, Cochrane Library (Central) and the clinical trials registries (http://www.controlled-trials.com and http://www.ClinicalTrials.gov) according to defined inclusion criteria (RCTs on AMD in English). Two independent reviewers evaluated studies for inclusion. One reviewer extracted data of included studies, and a second masked reviewer assessed 10% to confirm accuracy in data collection. Reference lists of included papers and appendices of relevant Cochrane systematic reviews were scanned to identify other relevant RCTs. Information collected on extracted outcomes was analysed using descriptive statistics.

RESULTS

Literature and registry search yielded 3816 abstracts of journal articles and 493 records from trial registries. A total of 177 RCTs were deemed to have met inclusion criteria. Of the 858 outcomes reported, 38 outcomes were identified as PROMs (4.4%). Of the 177 RCTs examined, PROMs were used in 25 trials (14.1%). The National Eye Institute Visual Function Questionnaire-25 was the most frequently used PROM instrument (64% of RCTs with PROMs included).

CONCLUSIONS

This review highlights that a small proportion of AMD RCTs included PROMs as outcome measures and that there was a variety in the instruments used.

TRIAL REGISTRATION NUMBER

The systematic review was registered in the PROSPERO database for systematic reviews, registration number CRD42014010040.

Scotopic microperimetry in the early diagnosis of age-related macular degeneration: preliminary study

Background. Recent clinical studies have shown that, in some degenerative retinal diseases, like age-related macular degeneration (AMD), the sensitivity of the rods decreases more rapidly than the sensitivity of the cones. The aim of this study was to evaluate if there is a correlation between the presence of hard drusen at the macular level and the rod damage responsible for the reduction in scotopic retinal sensitivity in subjects at risk for AMD. Methods. The authors selected 24 subjects (14 men and 10 women) with an average age of 67.25 ± 5.7 years. Macular hard drusen were present in 50% of the subjects at the fundus oculi exam. The researchers evaluated the retinal sensitivity to light in mesopic and scotopic conditions of each subject with an MP-1 scotopic microperimeter (MP-1S). Results. In subjects with hard drusen in the fundus oculi examination, there was a statistically significant reduction in scotopic retinal sensitivity, while the mesopic retinal sensitivity was not compromised. Conclusion. This study revealed how the presence of hard drusen at the macular level is associated with a reduction in scotopic retinal sensitivity compared to a control group of healthy subjects. Retinal functionality in a scotopic setting examined with MP-1S could be useful in early diagnosis of AMD.

New trends in visual rehabilitation with MP-1 microperimeter biofeedback: optic neural dysfunction

The aim of this study was to evaluate the efficacy of visual rehabilitation with MP-1 microperimeter biofeedback in advanced optic neural dysfunction due to glaucoma, and to precisely characterize fixation stability and location in affected patients. Ten patients (18 eyes) with advanced glaucoma were submitted to a rehabilitation protocol that consisted of: a 25-item questionnaire (National Eye Institute Visual Functioning Que stionnaire); measurement of visual acuity; a reading speed test; microperimetry with fixation study, retinal sensitivity and the bivariate contour ellipse area (BCEA). The rehabilitation program consisted of 10 training sessions of 10 minutes per eye performed over a period of one week and was repeated at four months, eight months, and one year. Statistical analysis was performed using the Student's t-test and Spearman correlation; p values less than 0.05 were considered statistically significant. In 13 eyes fixation changed from unstable to relatively unstable while its location changed from predominantly eccentric to predominantly central. In five eyes, fixation changed from relatively unstable to stable with a change of location from poor central fixation to predominantly New trends in visual rehabilitation with MP-1 microperimeter biofeedback: optic neural dysfunction central fixation. Mean retinal sensitivity changed from 7.43±8.28 dB to 8.33±9.04 dB (p<0.05); the mean best corrected visual acuity was 0.98±0.66 logMAR at the baseline assessment, and 0.75±0.6 logMAR at the end of rehabilitation (p>0.05); reading speed improved from a mean value of 31.4±4.3 words/minute to 55.6±3.2 words/minute at the end of the training (p<0.05). The BCEA changed from 0.94±0.39 deg2 to 0.86±0.46 deg2 (p=0.76). Rehabilitation with MP-1 biofeedback in patients with advanced glaucoma is a useful means of improving these patients' fixation stability, reading speed and quality of life.

How effective is eccentric viewing training? A systematic literature review

PURPOSE

The global prevalence of age-related macular degeneration and associated central vision loss is rising. Central vision loss hinders the performance of many activities of daily living. Adaptive strategies such as eccentric viewing and steady eye strategy may be used to compensate for central vision loss. In order to establish the potential of these rehabilitation strategies, this systematic review evaluates current literature regarding the effectiveness of eccentric viewing and steady eye strategy training in people with central vision loss.

RESULTS

The search strategies identified 2605 publications, 36 of which met the inclusion criteria for the review, but only three of which were randomised controlled trials. This literature shows that eccentric viewing and steady eye strategy training can improve near visual acuity, reading speed, and performance of activities of daily living in people with central vision loss. However, there was insufficient literature to establish a relationship between training and distance visual acuity or quality of life. There is no conclusive evidence to show that a particular model of eccentric viewing training is superior to another, little clear evidence of a relationship between participant characteristics and training outcomes and no data regarding the cost effectiveness of training.

CONCLUSION

This report highlights the need for further robust research to establish the true potential and cost effectiveness of eccentric viewing and steady eye strategy training as a rehabilitation strategy for individuals with central vision loss.

Biofeedback stimulation in patients with age-related macular degeneration: comparison between 2 different methods

OBJECTIVE

To evaluate changes in patient's visual performance after rehabilitation training with 2 different biofeedback training programs offered by the MP-1 microperimeter. Spontaneous retinal location of preferred retinal loci (PRLs) and fixation stability are not always optimal for best visual performances. MP-1 microperimeter biofeedback techniques have been suggested as modalities for training for better fixation stability and to find a better location of the new PRL in a more useful area of the retina in nonoptimal cases. The MP-1 microperimeter offers different biofeedback strategies, such as acoustic biofeedback and structured light stimulus plus acoustic biofeedback.

DESIGN

Retrospective study.

PARTICIPANTS

Thirty subjects affected by age-related macular degeneration with absolute central scotoma.

METHODS

A standard protocol of examination before and after visual rehabilitation training was performed on all study subjects. Assessment included demographics data, visual acuity, fixation stability, retinal sensitivity, and reading speed. Rehabilitation training was performed with standard and structured stimulus biofeedback. The whole sample was divided into 2 groups of 15 patients attending the 2 different stimulation training biofeedback.

RESULTS

Mean reading speed was found to be significantly increased for both groups (p < 0.05 and p < 0.01). Also, a statistically significant improvement of fixation stability was registered for both groups (p < 0.01). Only patients trained with the flickering pattern biofeedback stimulation increased retinal sensitivity (p < 0.01).

CONCLUSIONS

Both regular biofeedback and flickering pattern biofeedback training seem to improve visual functions. More benefits seem to be accrued, however, with flickering pattern biofeedback training.