VRT is supported by 15 years of research with clinical studies published in more than 30 leading journals including Nature Medicine, Neurology, and The Journal of Cognitive Neuroscience. Results in a retrospective study of 161 patients from 16 US Centers showed that more than 88% of patients experienced a functional improvement such as, improvements in their vision that impact their ability to read, walk, watch TV, and socialize comfortably1 with 75% stating they had better mobility. The average five degree improvement in central vision from VRT can make a significant difference in patients' daily lives, and more than 2,000 patients have been treated.
This open pilot describes a computerized training program which may possibly reduce the size of the "blind" visual field in patients with homonymous visual field deficits. Only two of the 11 patients with treatment showed no significant improvement in vision.
Brain damage is often accompanied by homonymous hemianopia, but few therapeutic approaches exist for visual field deficits. In this open pilot study we describe a computerized training program which may possibly reduce the size of the "blind" visual field in patients with homonymous visual field deficits. Various stimuli to test light perception and discrimination of colors and shapes were presented on a monitor which permitted the examination or training of the central section of the visual field up to about 25° vertical and 40° horizontal eccentricity.
Eleven patients trained at home for 1 h each day for a total of 80-300 h. Their results were compared with those of three patients who opted not to participate in the training procedure or those with very little therapy. These latter subjects had a slight decrease in the visual field size after about 1 year. In Contrast, the treatment group displayed a reliable enlargement of visual field size. This was revealed by a significant improvement in the detection of small light stimuli, an increase in the ability to discriminate colors and a minor, but notable, improvement in the of shape discrimination in the blind areas of the visual field. Additional training of shape recognition led to further improvement of shape discrimination, even when the patients trained with very different kinds of shapes, e.g. lines or letters.
Outcome depended on age of the patients and the size of the lesion, but it was independent of on-set of treatment and cause of the lesion. Only two of the 11 patients with treatment showed no significant improvement. This study suggests that regular home training of the "blind" visual field with computer-controlled stimuli may lead to improvement in vision. However, because of the following methodological limitations results are only preliminary: (1) the trial did not contain a true placebo group, (2) the patients were not assigned randomly to a control or treatment condition, (3) the lack of defined inclusion criteria considerably increased the variance in the neuropsychological performance. (4) because the experimental design was not double blind, experimenter bias cannot be ruled out, and (5) the conditions of the home training could not be standardized. The results warrant larger randomized, double-blind controlled trial.
The results of two independent clinical trials show that, contrary to conventional wisdom, partial blindness after a brain injury is treatable. Computer-based vision training is both a cost-efficient and effective way to improve vision in patients with visual-field defects.
Partial blindness after brain injury has been considered non-treatable. To evaluate whether patients with visual-field defects can profit from computer-based visual restitution training (VRT), two independent clinical trials were conducted using patients with optic nerve (n = 19) or post-chiasmatic brain injury (n = 19). In post-chiasma patients, VRT led to a significant improvement (29.4%) over baseline in the ability to detect visual stimuli; in optic nerve patients, the effects were even more pronounced (73.6% improvement). Visual-field enlargements were confirmed by the observation of a visual-field expansion of 4.9°–5.8° of visual angle and improved acuity in optic nerve patients. Ninety five percent of the VRT-treated patients showed improvements, 72.2% confirmed visual improvements subjectively.
Patients receiving a placebo training did not show comparable improvements. In conclusion, VRT with a computer program improves vision in patients with visual-field defects and offers a new, cost-effective therapy for partial blindness.
The study was used to evaluate the efficacy of Vision Restoration Therapy (VRT) in patients with post- chiasmatic brain damage using different functional perimetric tests. These were compared with measures of subjective vision and reaction time.
Abstract:
Purpose: We wished to evaluate the efficacy of vision restoration therapy (VRT) in patients with post-chiasmatic brain damage using different functional perimetric tests. These were compared with measures of subjective vision and reaction time.
Methods: An open trial was conducted with hemianopia/scotoma (n =16) patients. Before and after 6 months of VRT results of high resolution (HRP) and Tuebingen automated perimetry (TAP) were evaluated and compared to performance in a Scanning Laser Ophthalmoscope (SLO) as previously reported. Whereas TAP and HRP used above-threshold or near-threshold individual target stimuli on grey background, the SLO used a psychophysical task of detection of three black targets (reverse stimulus) on bright red, patterned background. Subjective testimonials of activities of daily living (ADL) were probed with questionnaires and interviews.
Results: Before VRT, the visual field border as assessed by SLO was located significantly closer to the vertical midline than the HRP and TAP border (border mismatch). After VRT the SLO border was still unchanged whereas HRP measurements revealed significant border shifts due to improved stimulus detection (p <0.0001) and improved reaction time (p <0.005) . Fewer misses were also observed in both eyes with TAP (p <0.01) which was primarily due to a significant shift of the absolute borders. Thus, VRT potentiated the mismatch between the SLO borders and the HRP/TAP borders. Fixation performance and the blind spot position remained unchanged after VRT. ADL ratings in the questionnaire improved significantly after VRT which was confirmed by independent patient testimonials.
Conclusions: We replicated earlier findings that VRT improves stimulus detection in HRP and TAP perimetry which were accompanied by subjective, visual improvements. These changes are not caused by fixation or eye movement artifacts. Because the SLO border was located significantly closer to the vertical midline before VRT (“border mismatch”) and, in contrast to HRP and TAP, did not change after VRT, we interpret this border mismatch to indicate that the SLO task was too difficult to perform and thus insensitive to VRT effects. Significant reaction time improvements indicate that plasticity of temporal processing might play an important role in vision restoration after brain damage. A further description of the precise psychophysical nature of the restored areas of residual vision is now warranted.
The goal of the study was to examine whether visual restitution training (VRT) is able to change absolute homonymous field defect, assessed with fundus-controlled microperimetry, in patients with hemianopia.
Aim: To examine whether visual restitution training (VRT) is able to change absolute homonymous field defect, assessed with fundus controlled microperimetry, in patients with hemianopia.
Methods: 17 patients with stable homonymous visual field defects before and after a 6 month VRT period were investigated with a specialised microperimetric method using a scanning laser ophthalmoscope (SLO). Fixation was controlled by SLO fundus monitoring. The size of the field defect was quantified by calculating the ratio of the number of absolute defects and the number of test points; the training effect E was defined as the difference between these two ratios before and after training. A shift of the entire vertical visual field border by 1˚ would result in an E value of 0.14.
Results: The mean training effect of all right eyes was E = 0.025 (SD 0.052) and all left eyes E = 0.008 (SD0.034). In one eye, a slight non-homonymous improvement along the horizontal meridian occurred.
Conclusions: In one patient, a slight improvement along the horizontal meridian was found in one eye. In none of the patients was an explicit homonymous change of the absolute field defect border observed after training.
Sixteen patients were examined with stable homonymous visual field defects (HVFDs) with static automated perimetry (SAP). Training effect was defined as difference of the proportions of absolutely defective locations in all test locations, before and after visual restitution training (VRT).
The authors examined 16 patients with stable homonymous visual field defects (HVFDs) with static automated perimetry (SAP). Training effect E was defined as difference of the proportions of absolutely defective locations in all test locations, before and after visual restitution training (VRT). E was 0.05 ± 0.05 (mean ± SD). The authors observed a relevant training effect (E ≥ 0.12) in two subjects, but only monocularly. VRT has little effect on absolute HVFDs in SAP.
Of patients with stable VFDs due to stroke or traumatic brain injury from 16 US Centers (n=161) who completed 6 modules of VRT, 70 % experienced visual improvements, with an average stimulus detection improvement of 12.8% or a 4.9º border shift between the seeing and the blind field.
Abstract
Background: The objective of this study was to determine the effect of a visual rehabilitation intervention on visual field defects in a US cohort. Vision Restoration Therapy (VRT) consists of a specific pattern of stimulation that is directed at the border of the blind field.
Methods: This retrospective study evaluated individuals with homonymous visual field defect from retrochiasmatic lesions treated with 6 modules of VRT. Suprathreshold visual field testing of the central 43×32 was obtained at baseline and after each module. The main outcome measures were the change in stimuli detection and the shift in the position of the border of the blind field. The impact of age, time from injury and type of visual field defect were analyzed.
Results: Among 161 patients, the mean absolute improvement in stimuli detection was 12.8%. The average border shift was 4.87. Improvements of ≥3% was noted in 76% of patients. Absolute change in stimulus detection of ≥3% at mid-therapy was associated with a greater final improvement. Age, time from lesion and type of visual field defect did not influence the degree of field expansion.
Conclusions: VRT improves stimulus detection and results in a shift of the position of the border of the blind field as measured on suprathreshold visual field testing. These results support prior reports and support VRT as a useful rehabilitative intervention for a proportion of patients with visual field defects from retrochiasmatic lesions.
In small experimental trials, vision restoration therapy (VRT), a home-based rehabilitation method, has shown to enlarge the visual field and improve reaction times in patients with lesion involving the CNS. We now evaluated the outcome of VRT in a large sample of clinical patients and studied factors contributing to subjective and objective measures of visual field alterations.
Abstract
Purpose: In small experimental trials, vision restoration therapy (VRT), a home-based rehabilitation method, has shown to enlarge the visual field and improve reaction times in patients with lesion involving the CNS. We now evaluated the outcome of VRT in a large sample of clinical patients and studied factors contributing to subjective and objective measures of
visual field alterations.
Methods: Clinical observational analysis of visual fields of 302 patients before and after being treated with computer-based vision restoration therapy for a period of 6 months at eight clinical centers in central Europe. The visual field defects were due to ischemia, hemorrhage, head trauma, tumor removal or anterior ischemic optic neuropathy. Primary outcome measure was a visual field assessment with super-threshold perimetry. Additionally, conventional near-threshold perimetry, eye movements and subjective reports of daily life activities were assessed in a subset of the patients.
Results: VRT improved patients' ability to detect super-threshold stimuli in the previously deficient area of the visual field by 17.2% and these detection gains were not significantly correlated with eye movements. Notable improvements were seen in 70.9% of the patients. Efficacy was independent of lesion age and etiology, but patients with larger areas of residual vision at baseline and patients > 65 years old benefited most. Conventional perimetry validated visual field enlargements and patient testimonials confirmed the improvement in every day visual functions. Conclusions: VRT improves visual functions in a large clinical sample of patients with visual field defects involving the CNS, confirming former experimental studies.
In patients suffering visual field loss after stroke or TBI, VRT for 6 months leads to visual field size increases. When VRT is discontinued, the visual field gains are stable over a period of at least 23 months.
Patients with cerebral lesions can maintain or even increase the significant visual field enlargements induced by computer training (therapy)—even two years after training is discontinued.
Abstract
In a previous randomized placebo-controlled clinical trial, we observed significant visual field enlargements induced by computer-based restitution training in patients with cerebral lesions (Kasten et al., Nature med., 4, 1998, 1083±87). Now we asked the question whether this effect is stable after training was discontinued? Here we report data of a follow-up study after a training-free interval (mean 23.5±2.3 months after end of therapy). 16 patients of the original restitution group and 6 patients of the placebo group were re-examined. On average, in high resolution computer campimetry (stimulus detection: PeriMa, form recognition: PeriForm, color perception: PeriColor) as well as in conventional automatic perimetry (TAP-2000) both groups showed no significant decline in the number of correctly detected stimuli after training was discontinued. However, cluster analysis revealed three different types of patients, who showed either increase (Type-I), decrease (Type-II) or stability (Type-III) in performance. We propose that many patients learn to use the regained visual capacities not only in the setting of a computer training but also in every day life, while other patients do not use the areas of restored vision and show a decrease of visual functions after the end of training. The Type-I group does not need continuous training, while the Type-II group may benefit from phases of refreshment exercises.
Systematic stimulation of the visual field border in patients with visual field loss after cerebral lesion improves visual function even years after the onset of partial blindness.
Abstract.
Purpose: Systematic stimulation of the visual field border in patients with visual field loss after cerebral lesions improves visual function even years after the onset of partial blindness. However, computer-based training programs like Vision Restoration Training (VRT) are not equally effective in all patients. We therefore tested which factors determine training outcome and which visual and cognitive functions are changed by VRT.
Methods: Multiple outcome measures were predicted using a multifactorial regression approach. Nineteen patients with postgeniculate visual system lesions performed six months of VRT and underwent extensive testing before and after treatment, including visual field measurements, attention functions, and subjective parameters.
Results: Visual field size increased significantly during training, but a number of cognitive, especially attentional, variables also improved, as did subjective visual function. The size of areas of residual vision was the strongest predictor variable for visual field increase. Demographic and lesion-related variables had little influence on training success.
Conclusions: With multivariate regression models, training outcome on different variables can be accurately predicted. Moreover, visual field increase is sufficiently predictable based on a set of variables readily available to the clinician: age of the patient, time since lesion, number of absolute perimetric defects, eccentricity of the visual field border, size of areas of residual vision, and average reaction time to perimetric stimuli.
