***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: 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 43x32 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 > or =3 % was noted in 76 % of patients . Absolute change in stimulus detection of > or =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 Background : Neurologically impaired persons seem to benefit from driving-training programs , but there is no convincing evidence to support this notion . The authors therefore investigated the effect of simulator-based training on driving after stroke . Methods : Eighty-three first-ever subacute stroke patients entered a 5-week 15-hour training program in which they were r and omly allocated to either an experimental ( simulator-based training ) or control ( driving-related cognitive tasks ) group . Performance in off-road evaluations and an on-road test were used to assess the driving ability of subjects pre- and post-training . Outcome of an official predriving assessment administered 6 to 9 months poststroke was also considered . Results : Both groups significantly improved in a visual and many neuropsychological evaluations and in the on-road test after training . There were no significant differences between both groups in improvements from pre- to post-training except in the “ road sign recognition test ” in which the experimental subjects improved more . Significant improvements in the three-class decision ( “ fit to drive , ” “ temporarily unfit to drive , ” and “ unfit to drive ” ) were found in favor of the experimental group post-training . Academic qualification and overall disability together determined subjects that benefited most from the simulator-based driving training . Significantly more experimental subjects ( 73 % ) than control subjects ( 42 % ) passed the follow-up official predriving assessment and were legally allowed to resume driving . Conclusions : Simulator-based driving training improved driving ability , especially for well educated and less disabled stroke patients . However , the findings of the study may have been modified as a result of the large number of dropouts and the possibility of some neurologic recovery unrelated to training PURPOSE ( 1 ) To compare the outcomes of orientation and mobility and driving training with Fresnel prisms and the Gottlieb Visual Field Awareness System for patients with homonymous hemianopsia , and ( 2 ) To determine whether the patients continue to use the optical enhancement devices at a 2-year follow-up point . METHODS Patients with homonymous hemianopsia were provided with a rehabilitation program where they were fitted with prism lenses and trained to use them for navigation and driving . Telephone interviews were used to obtain information about device usage 2 years following the completion of the training program . RESULTS Patients ' performance was compared with a test-retest criterion in the visual skills areas of recognition , mobility , peripheral detection , scanning , tracking , and visual memory .  Patients with hemianopic loss showed improvements in all of the visual skills categories , ranging from the highest improvements of 26 % of tasks improved in the mobility category to 13 % in the recognition category . The majority of the hemianopic patients reported using the devices at the 2-year follow-up interview . CONCLUSIONS The patients with homonymous hemianopsia showed improvements in visual functioning using prism lenses , although these improvements were smaller than those found in previous studies with central or bilateral peripheral vision loss groups who were trained to use other optical enhancement devices for navigation and driving using a similar curriculum . However , given the evidence of increased risk of accidents for patients with peripheral vision loss , the safety of peripheral enhancement devices for driving must be thoroughly evaluated before their impact on public safety is known This article reports on two studies that examine the relationship between measurements of activities of daily living ( ADL ) and cognitive skills performance . Study 1 is a post hoc analysis of ADL improvement scores collected on acute stroke patients who were either given or not given cognitive skills remediation .  An examination of individual ADL scores showed significantly higher personal hygiene , bathing , and toilet activity improvement scores for patients receiving  cognitive skills remediation .  In Study 2 , cognitive skills and ADL pre- and posttest scores for stroke patients were measured by occupational therapists , who also implemented an ADL as well as a cognitive skills remediation program as part of the patient 's therapy . Some significant positive correlations between initial cognitive skills measurements and ADL outcome were found . The best correlate of patients ' ADL performance at discharge was performance on an auditory attention task . Verbal comprehension correlated with overall ADL improvement , and overall cognitive skills improvement correlated with overall ADL improvement . Implication s of these two studies are discussed BACKGROUND the types of visual impairment followings stroke are wide ranging and encompass low vision , eye movement and visual field abnormalities , and visual perceptual difficulties . OBJECTIVE the purpose of this paper is to present a 1-year data set and identify the types of visual impairment occurring following stroke and their prevalence . METHODS a multi-centre prospect i ve observation study was undertaken in 14 acute trust hospitals . Stroke survivors with a suspected visual difficulty were recruited . St and ardised screening/referral and investigation forms were employed to document data on visual impairment specifically assessment of visual acuity , ocular pathology , eye alignment and movement , visual perception ( including inattention ) and visual field defects . RESULTS three hundred and twenty-three patients were recruited with a mean age of 69 years [ st and ard deviation ( SD ) 15 ] . Sixty-eight per cent had eye alignment/movement impairment , 49 % had visual field impairment , 26.5 % had low vision and 20.5 % had perceptual difficulties . CONCLUSIONS of patients referred with a suspected visual difficulty , only 8 % had normal vision status confirmed on examination . Ninety-two per cent had visual impairment of some form confirmed which is considerably higher than previous publications and probably relates to the prospect i ve , st and ardised investigation offered by specialist orthoptists . However , under-ascertainment of visual problems can not be ruled out Objective : An acquired right-sided homonymous hemianopia can result in slowed left-to-right text reading , called hemianopic alexia ( HA ) . Patients with HA lack essential visual information to help guide ensuing reading fixations . We tested two hypotheses : first , that practice with a visual rehabilitation method that induced small-field optokinetic nystagmus ( OKN ) would improve reading speeds in patients with HA when compared to a sham visual rehabilitation therapy ; second , that this therapy would preferentially affect reading saccades into the blind field . Methods : Nineteen patients with HA were entered into a two-armed study with two therapy blocks in each arm : one group practice d reading moving text ( MT ) that scrolled from right to left daily for two 4-week blocks ( Group1 ) , while the other had sham therapy ( spot the difference ) for the first block and then crossed over to MT for the second . Results : Group 1 showed significant improvements in static text reading speed over both therapy blocks ( 18 % improvement ) , while Group 2 did not significantly improve over the first block ( 5 % improvement ) but did when they crossed over to the MT block ( 23 % improvement ) . MT therapy was associated with a direction-specific effect on saccadic amplitude for rightward but not leftward reading saccades . Conclusion : Optokinetic nystagmus inducing therapy preferentially affects reading saccades in the direction of the induced ( involuntary ) saccadic component . This is the first study to demonstrate the effectiveness of a specific eye movement based therapy in patients with hemianopic alexia ( HA ) in the context of a therapy-controlled trial . A free Web-based version of the therapy used in this study is available online to suitable patients with HA Background : In patients with postgenicular lesions of the visual system , areas of residual vision ( ARVs ) are the main predictor of recovery induced by vision restoration therapy ( VRT ) . In these partially defective regions , the elevated perceptual thresholds can be acutely reduced by attentional cueing . Objective : To examine whether directing attention to ARVs using a visuospatial cue also increases long-term neural plasticity and thus enhances permanent training outcome . Methods : In a prospect i ve , r and omized clinical trial , treatment outcome was compared in patients with postgenicular visual system lesions who received either st and ard VRT ( control group [ CG ] ; n = 10 ) or VRT with attentional cueing ( experimental group [ EG ] ; n = 9 ) .  Visual field size was determined before and after a 6-month treatment period using Tübingen Automated Perimetry and computer-based high-resolution perimetry ( HRP ) and in regular intervals throughout this period by HRP and detection performance in VRT . Results : In the area of the cue , restoration of vision was significantly greater than during VRT without cueing : cued patients showed a much more pronounced shift of the visual field border toward the blind area than that observed in the CG or in uncued regions of the EG . Focusing attention at ARVs during treatment changed topographic and temporal patterns of recovery as compared with uncued regions of the visual field . Conclusions : Use of a visuospatial cue to focus attention at areas of residual vision amplifies long-term neuronal plasticity . The authors propose that top-down signals preactivate partially damaged areas of V1 , thus linking visual and attentional neuronal networks , with the effect of permanently increasing conscious visual perception Objective : Patients with homonymous hemianopia are disabled on everyday exploratory activities . We examined whether explorative saccade training ( EST ) , compared with flicker-stimulation training ( FT ) , would selectively improve saccadic behavior on the patients ’ blind side and benefit performance on natural exploratory tasks . Methods : Twenty-eight hemianopic patients were r and omly assigned to distinct groups performing for 6 weeks either EST ( a digit- search task ) or FT ( blind-hemifield stimulation by flickering letters ) . Outcome variables ( response times [ RTs ] during natural search , number of fixations during natural scene exploration , fixation stability , visual fields , and quality -of-life scores ) were collected before , directly after , and 6 weeks after training . Results : EST yielded a reduced ( post/pre , 47 % ) digit- search RT for the blind side . Natural search RT decreased ( post/pre , 23 % ) on the blind side but not on the seeing side . After FT , both sides ’ RT remained unchanged . Only with EST did the number of fixations during natural scene exploration increase toward the blind and decrease on the seeing side ( follow-up/pre difference , 238 % ) . Even with the target located on the seeing side , after EST more fixations occurred toward the blind side . The EST group showed decreased ( post/pre , 43 % ) fixation stability and increased ( post/pre , 482 % ) asymmetry of fixations toward the blind side . Visual field size remained constant after both treatments . EST patients reported improvements in social domain . Conclusions : Explorative saccade training selectively improves saccadic behavior , natural search , and scene exploration on the blind side . Flicker-stimulation training does not improve saccadic behavior or visual fields . The findings show substantial benefits of compensatory exploration training , including subjective improvements in mastering daily-life activities , in a r and omized controlled trial 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 Visual field deficits in patients have long been considered to be nontreatable , but in previous studies we have found an enlargement of the intact visual field following vision restoration therapy ( VRT ) . In the present pilot study , we wished to determine whether a double-stimulation approach would facilitate visual field enlargements beyond those achieved by the single-stimulus paradigm used in st and ard VRT . This was motivated by the findings that following visual cortex injury in animals , the size of receptive fields could be enlarged by systematic costimulation , where two stimuli were used to excite visual cortex neurons ( Eysel , Eyding , & Schweigart , 1998 ) . Patients ( n = 23 ) with stable homonymous field deficits after trauma , cerebral ischemia , or hemorrhage ( lesion age > 6 months ) carried out either ( a ) st and ard VRT with a single stimulation ( n = 9 ) , or vision therapy with ( b ) a parallel cost 
    Output:
    
AUTHORS ' CONCLUSIONS There is limited evidence which supports the use of compensatory scanning training for patients with visual field defects ( and possibly co-existing visual neglect ) to improve scanning and reading outcomes .
There is insufficient evidence to reach a conclusion about the impact of compensatory scanning training on functional activities of daily living .
There is insufficient evidence to reach generalised conclusions about the benefits of visual restitution training ( VRT ) ( restitutive intervention ) or prisms ( substitutive intervention ) for patients with visual field defects after stroke