Homonymous Visual Field Loss Research Articles

Driving Difficulties and Coping Strategies in Persons With Homonymous Quadrantanopia or Homonymous Scotoma

Introduction: This study, conducted in the United States, investigated the challenges faced by drivers with homonymous visual field loss and their coping strategies, including the use of in-vehicle Advanced Driver Assistance Systems (ADAS). Methods: Four current drivers with either homonymous quadrantanopia or homonymous scotoma caused by a stroke completed an in-depth semi-structured telephone interview. Using mostly open-ended questions, the interview addressed the difficulties encountered while driving, strategies used to cope with the difficulties, and the use of ADAS. Results: The main difficulties related to seeing objects on the side of the field loss, especially at intersections and when merging or changing lanes. Individuals with left-sided field loss reported problems with left turns and seeing oncoming cars at intersections. Those who had homonymous scotomas described how cars disappeared in and out of the scotoma. Two participants reported many driving difficulties at first, but fewer difficulties as they became used to driving with the field loss. The most common coping strategies included scanning to the side of the field loss (including large scans with head movements), use of rearview and side mirrors, adding mirrors to the car, leaving more space on the side of the field loss, avoiding difficult driving situations and the use of ADAS (blind spot warning, GPS navigation, and rearview camera). Discussion: All participants reported some difficulties consistent with those found in on-road and driving simulator studies of individuals with homonymous visual field loss. Over time they each reported developing a set of strategies, including the use of ADAS, for coping with the field loss that enabled them to be active drivers with relatively few self-imposed restrictions. Implications for Practitioners: Advising drivers with stroke-related field loss about potential difficulties and compensatory strategies is an important part of preparation for return to driving. This article provides examples of problem situations, coping strategies, and ADAS use which can be used to guide discussion.

Knowing me, knowing you-A study on top-down requirements for compensatory scanning in drivers with homonymous visual field loss.

It is currently still unknown why some drivers with visual field loss can compensate well for their visual impairment while others adopt ineffective strategies. This paper contributes to the methodological investigation of the associated top-down mechanisms and aims at validating a theoretical model on the requirements for successful compensation among drivers with homonymous visual field loss. A driving simulator study was conducted with eight participants with homonymous visual field loss and eight participants with normal vision. Participants drove through an urban surrounding and experienced a baseline scenario and scenarios with visual precursors indicating increased likelihoods of crossing hazards. Novel measures for the assessment of the mental model of their visual abilities, the mental model of the driving scene and the perceived attention demand were developed and used to investigate the top-down mechanisms behind attention allocation and hazard avoidance. Participants with an overestimation of their visual field size tended to prioritize their seeing side over their blind side both in subjective and objective measures. The mental model of the driving scene showed close relations to the subjective and actual attention allocation. While participants with homonymous visual field loss were less anticipatory in their usage of the visual precursors and showed poorer performances compared to participants with normal vision, the results indicate a stronger reliance on top-down mechanism for drivers with visual impairments. A subjective focus on the seeing side or on near peripheries more frequently led to bad performances in terms of collisions with crossing cyclists. The study yielded promising indicators for the potential of novel measures to elucidate top-down mechanisms in drivers with homonymous visual field loss. Furthermore, the results largely support the model of requirements for successful compensatory scanning. The findings highlight the importance of individualized interventions and driver assistance systems tailored to address these mechanisms.

Post Stroke, Is Perimetry Necessary? A Case Report

Abstract
 Introduction : Stroke are generally associated with peripheral visual field loss. Three out of four stroke patients report some form of disability, one of which is visual impairment. Approximately 16% of these patients have a homonymous visual field defect poststroke. These vision problems can lead to difficulty carrying out a lot of daily tasks and activities, such as driving. This report tries to define the diagnostic flow to determine the exact type and lesion.
 Case Illustration : Male, 61 years old, came to Universitas Sumatera Utara Hospital with visual field loss in both eyes. Two months ago, he was diagnosed with ischemic stroke and treated with Aspirin 80 mg, with no limbs disability right now. He also had hypertension and treated with Amlodipine 10 mg. VOD: 6/60 with BCVA S-2.00 6/7,5, VOS: 6/60 with BCVA S-2.00 6/7.5. With confrontation test and perimetry, defect was found in medial visual field OD and lateral visual field OS. Hess screen and Amsler Grid was normal. Head CT-Scan was performed with multiple infarcts, mainly in right occipital lobe. The patient was diagnosed with Incomplete Hemianopia, Left Congruous Homonymous Hemianopia with Macular Sparing, and treated with Citicholine 1000 mg once daily.
 Discussion
 Conclusion : In stroke patients with homonymous visual field loss, visual field testing with detailed evaluation of visual field defect can determine the lesion location, and neuro-radiological imaging was necessary to assess visual pathway. It’s important for educate the patients, diagnostic and prevent the stroke recurrent.

Retinal Pseudocysts in a Patient with Homonymous Hemianopia

A 33-year-old woman presented for evaluation with a history of craniopharyngioma, status postresection in childhood. Fundoscopic examination showed bilateral optic nerve pallor (A) and Humphrey Visual Field 24-2 revealed a left homonymous hemianopia (B). Spectral domain en-face OCT imaging demonstrated hemi-macular hyporeflectivity respecting the vertical mid-line (C). Structural B-scan showed retinal pseudocysts temporally in the right eye (D, top) and nasally in the left eye (D, bottom), corresponding with the left homonymous defect. Retinal pseudocysts have been described in cases of advanced optic atrophy. This is a rare case of retinal pseudocysts in the setting of homonymous visual field loss secondary to a compressive lesion. (Magnified version of Figure A-D is available online at www.aaojournal.org).

Neuro-Ophthalmic Visual Impairment in the Setting of COVID-19.

We set out to describe in detail the afferent neuro-ophthalmological complications that have been reported in association with coronavirus disease 2019 (COVID-19) infection. We describe and elaborate on mechanisms of disease, including para-infectious inflammation, hypercoagulability, endothelial damage, and direct neurotropic viral invasion. Despite global vaccination programs, new variants of COVID-19 continue to pose an international threat, and patients with rare neuro-ophthalmic complications are likely to continue to present for care.Afferent complications from COVID-19 include homonymous visual field loss, with or without higher cortical visual syndromes, resulting from stroke, intracerebral hemorrhage, or posterior reversible leukoencephalopathy. Optic neuritis has frequently been reported, sometimes along with acute disseminated encephalomyelopathy, often in association with either myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) or less commonly aquaporin-4 seropositivity or in newly diagnosed multiple sclerosis. Ischemic optic neuropathy has rarely been reported. Papilledema, resulting either from venous sinus thrombosis or idiopathic intracranial hypertension in the setting of COVID-19, has also been described.Observed afferent neuro-ophthalmic associations need to be confirmed though larger comparative studies. Meanwhile, the range of possible complications should be recognized by neurologists and ophthalmologists alike, to facilitate faster diagnosis and treatment of both COVID-19 and its neuro-ophthalmic manifestations.

The Effects of Visual Field Loss from Stroke on Performance in a Driving Simulator.

Visual field loss is a common consequence of stroke and often precludes driving. However, legal visual requirements for drivers' licenses are largely without scientific basis. This study aimed to examine the effects of different types of homonymous visual field loss after stroke on simulated driving. Data on performance and safety from a traffic simulator test for 153 participants with withdrawn drivers' licenses due to visual field loss from stroke were retrospectively compared with data from 83 healthy individuals without visual deficits in a cross-sectional study. The 93 individuals in the stroke group who regained their driving licenses after a successful simulator test were then followed in a national accident database. Sixty-five percent of the stroke participants passed the simulator test (95% confidence interval, 57 to 72%). Younger patients were more successful than older. However, classification by neither type of homonymous visual field loss nor side of visual field loss was predictive of driver safety. Participants with hemianopia had their lateral lane position dislocated to the nonaffected side of the visual field. None of the participants with a regained license were involved in motor vehicle accidents 3 to 6 years after the test. In this large cohort, driver safety could not be predicted from the type of homonymous visual field loss. Even individuals with severe visual field loss might be safe drivers. Therefore, it seems reasonable to provide an opportunity for individualized assessments of practical fitness to drive in circumstances of licensing issues. This study demonstrates the potential of using a standardized driving simulator test for such assessments of fitness to drive.

Acute Postoperative Visual Loss Due to Occipital Arteriovenous Malformation Rupture During Anesthesia

<p>We report a case of occipital arteriovenous malformation (AVM) rupture during anaesthesia, causing postoperative visual loss in a 43-year-old man with American Society of Anesthesiologist class I. He was scheduled for an operation for the correction of right index deformity. He was a healthy, middle-sized man without any previous systemic disease. He had sustained a cutting injury to the right index finger 1 year ago and had undergone microsurgery. As he was unsatisfied with the surgical results, he was arranged for another correction surgery. After the 2-h surgery, he recovered from anaesthesia, but complained of a mild headache over the occipital region. He left the post-operative recovery room thereafter and was discharged the next day. Three days later, he came to our surgical outpatient department for follow-up. He complained of blurred vision since the surgery. The ophthalmologist found left-sided homonymous visual field loss with incomplete hemianopia. He was referred to the neurological section and after a series of examinations including brain computed tomography, the diagnosis of AVM rupture in the right occipital region was confirmed.</p> <p> </p>

Change blindness in simulated driving in individuals with homonymous visual field loss

Individuals with homonymous visual field loss (HVFL) fail to perceive visual information that falls within the blind portions of their visual field. This places additional burden on memory to represent information in their blind visual field, which may make visual changes in the scene more difficult to detect. Failing to detect changes could have serious implications in the context of driving. A change blindness driving simulator experiment was conducted with individuals with HVFL (n = 17) and in those with normal vision (NV; n = 16) where changes (pedestrians appearing) were triggered based on the driver’s gaze location. Gaze was used to ensure that the location of the change was visible before and after the change occurred. There were wide individual differences in both vision groups, ranging from no change blindness to more than 33% of events. Those with HVFL had more change blindness than those with NV (16.7% vs. 6.3%, p < 0.001) and more change blindness to pedestrians appearing in their blind than seeing hemifield (34.6% vs. 10.4%, p < 0.001). Further, there was more change blindness for events appearing in the seeing hemifield for those with HVFL than normal vision (p = 0.023). These results suggest that individuals with HVFL may be more susceptible to failures of awareness, such as change blindness, than individuals with normal vision. Increased risk for failures of awareness may result in motor vehicle crashes where the driver fails to notice the other road user (looked-but-failed-to-see incidents).

Spared perilesional V1 activity underlies training-induced recovery of luminance detection sensitivity in cortically-blind patients

Damage to the primary visual cortex (V1) causes homonymous visual-field loss long considered intractable. Multiple studies now show that perceptual training can restore visual functions in chronic cortically-induced blindness (CB). A popular hypothesis is that training can harness residual visual functions by recruiting intact extrageniculostriate pathways. Training may also induce plastic changes within spared regions of the damaged V1. Here, we link changes in luminance detection sensitivity with retinotopic fMRI activity before and after visual discrimination training in eleven patients with chronic, stroke-induced CB. We show that spared V1 activity representing perimetrically-blind locations prior to training predicts the amount of training-induced recovery of luminance detection sensitivity. Additionally, training results in an enlargement of population receptive fields in perilesional V1, which increases blind-field coverage and may support further recovery with subsequent training. These findings uncover fundamental changes in perilesional V1 cortex underlying training-induced restoration of conscious luminance detection sensitivity in CB.

Increased Visual Sensitivity and Occipital Activity in Patients With Hemianopia Following Vision Rehabilitation.

Hemianopia, loss of vision in half of the visual field, results from damage to the visual pathway posterior to the optic chiasm. Despite negative effects on quality of life, few rehabilitation options are currently available. Recently, several long-term training programs have been developed that show visual improvement within the blind field, although little is known of the underlying neural changes. Here, we have investigated functional and structural changes in the brain associated with visual rehabilitation. Seven human participants with occipital lobe damage enrolled in a visual training program to distinguish which of two intervals contained a drifting Gabor patch presented within the blind field. Participants performed ∼25 min of training each day for 3–6 months and undertook psychophysical tests and a magnetic resonance imaging scan before and after training. A control group undertook psychophysical tests before and after an equivalent period without training. Participants who were not at ceiling on baseline tests showed on average 9.6% improvement in Gabor detection, 8.3% in detection of moving dots, and 9.9% improvement in direction discrimination after training. Importantly, psychophysical improvement only correlated with improvement in Humphrey perimetry in the trained region of the visual field. Whole-brain analysis showed an increased neural response to moving stimuli in the blind visual field in motion area V5/hMT. Using a region-of-interest approach, training had a significant effect on the blood oxygenation level-dependent signal compared with baseline. Moreover, baseline V5/hMT activity was correlated to the amount of improvement in visual sensitivity using psychophysical and perimetry tests. This study, identifying a critical role for V5/hMT in boosting visual function, may allow us to determine which patients may benefit most from training and design adjunct interventions to increase training effects.SIGNIFICANCE STATEMENT Homonymous visual field loss is a common consequence of brain injury and is estimated to affect more than 230,000 people in the United Kingdom. Despite its high prevalence and well-described impact on quality of life, treatments to improve visual sensitivity remain experimental, and deficits are considered permanent after 6 months. Our study shows that behavioral changes following vision rehabilitation are associated with enhanced visually-evoked occipital activity to stimuli in the blind visual field. Unlike previous behavioral studies, we observe clinical changes that are specific to the trained region of vision. This lends significant weight to such training paradigms and offers a mechanism by which visual function can be improved despite damage to the primary visual pathway.

Evaluation of Eyelander, a Video Game Designed to Engage Children and Young People with Homonymous Visual Field Loss in Compensatory Training

Introduction Rehabilitation can improve visual outcomes for adults with acquired homonymous visual field loss. It is unclear, however, whether rehabilitation improves visual outcomes for children because previous training schedules have been tiresome, uninteresting, and have failed to keep them engaged. In this study, we assessed whether children and young people with homonymous visual field loss would adhere to six weeks of unsupervised compensatory training using a specialized video game. Methods Participants aged between 7 and 25 years with homonymous visual field loss completed tabletop assessments of visual search across four site visits. Two baseline assessments separated by four weeks evaluated spontaneous improvements before training began. Participants were then given a copy of the video game to use unsupervised at home for six weeks. Two follow-up assessments separated by four weeks were then conducted to evaluate immediate and acutely maintained effects of training. Results Fifteen candidates met the inclusion-exclusion criteria, nine participated, and eight completed the study. Participants completed an average of 5.6 hours of unsupervised training over the six weeks. Improvements on in-game metrics plateaued during week three of training. The time taken to find objects during tabletop activities improved by an average of 24%–95% CI (2%, 46%)—after training. Discussion The findings demonstrate that children and young people with homonymous visual field loss will engage with gamified compensatory training, and it can improve visual outcomes with less of a time commitment than has been required of adults participating in non-gamified training in previous studies. Appropriately powered, randomized controlled trials are required to evaluate the validity and generalizability of observed training effects. Implications for practitioners Rehabilitation specialists can use specialist video games and gamification technique to engage children and young people with homonymous visual field loss in long-term unsupervised training schedules.

Review of rehabilitation and habilitation strategies for children and young people with homonymous visual field loss caused by cerebral vision impairment

Partial and homonymous visual field loss (HVFL) is a common consequence of post-chiasmatic injury to the primary visual pathway or injury to the primary visual cortex. Different approaches to rehabilitation have been reported for older adults with HVFL and there is evidence to support the use of compensatory training over other proposed therapies. We reviewed the literature to investigate the current state of the art of rehabilitation and habilitation strategies for children and young people with HVFL, and whether there is enough evidence to support the use of these strategies in the paediatric population. We have provided an overview of the existing literature on children and young people with HVFL, a brief overview of rehabilitation strategies for adults with HVFL, and evidence on whether these different interventions have been applied with children and young people effectively. We found that there have been very few studies to investigate these strategies with children and young people, and the quality of evidence is currently low. New research is required to evaluate which strategies are effective for children and young people with HVFL and whether new strategies need to be developed.

Progression of transsynaptic retinal degeneration with spectral-domain optical coherence tomography

PurposeTo illustrate the progression of retrograde transsynaptic retinal degeneration using spectral-domain optical coherence tomography (SD-OCT). ObservationsA 60 year-old man with a stroke was followed over a 17-month period using SD-OCT of the macula, ganglion cell layer (GCC), and retinal nerve fiber layer. Transsynaptic retinal degeneration progressed over this time. Conclusions and importanceRetrograde transsynaptic retinal degeneration may occur in patients with homonymous visual field loss caused by post-geniculate neurologic disease. This is best detected as homonymous thinning of the retina, corresponding to the pattern of visual field loss, using SD-OCT of the GCC and macula. The retinal changes occur at a variable time following the onset of neurologic disease.

Transsynaptic Retrograde Degeneration: Clinical Evidence with Homonymous RGCL Loss on OCT.

Retinal thinning after a retrogeniculate lesion (transsynaptic retrograde degeneration) was first described 50 years ago, but has long been a controversial issue. It is now possible to use OCT for the in vivo measurement of retinal thickness. This was a retrospective study of patients with homonymous visual field loss, with SD-OCT assessment (RNFL and RGCL measurements) in isolated retrogeniculate lesions, subsequently confirmed by a neuroradiologist. Nine patients with vascular, inflammatory or tumour brain lesions were included in the study. Homonymous RGCL thinning was found in all patients, and correlated with the visual field defect. No correlation was found with RNFL. The homonymous defect of RGCL in patients with retrogeniculate lesions demonstrates the presence of transsynaptic retrograde degeneration. RGCL is a better predictor of visual field defects than RNFL measurement.

Use of NeuroEyeCoach™ to Improve Eye Movement Efficacy in Patients with Homonymous Visual Field Loss.

Visual field deficits are common in patients with damaged retinogeniculostriate pathways. The patient's eye movements are often affected leading to inefficient visual search. Systematic eye movement training also called compensatory therapy is needed to allow patients to develop effective coping strategies. There is a lack of evidence-based, clinical gold-standard registered medical device accessible to patients at home or in clinical settings and NeuroEyeCoach (NEC) is developed to address this need. In three experiments, we report on performance of patients on NEC compared to the data obtained previously on the earlier versions of the search task (n = 32); we assessed whether the self-administered computerised tasks can be used to monitor the progress (n = 24) and compared the findings in a subgroup of patients to a healthy control group. Performance on cancellation tasks, simple visual search, and self-reported responses on activities of daily living was compared, before and after training. Patients performed similarly well on NEC as on previous versions of the therapy; the inbuilt functionality for pre- and postevaluation functions was sensitive to allowing assessment of improvements; and improvements in patients were significantly greater than those in a group of healthy adults. In conclusion, NeuroEyeCoach can be used as an effective rehabilitation tool to develop compensatory strategies in patients with visual field deficits after brain injury.

Pediatric Balint's Syndrome Variant: A Possible Diagnosis in Children.

Balint's syndrome is well described in adults, but not in children. It is caused by bilateral posterior parietal lobe damage and comprises a triad of simultanagnosia (inability to simultaneously see more than a small number of items), optic ataxia (impaired visual guidance of movement of the limbs and body), and apraxia of gaze (inability to volitionally direct gaze despite the requisite motor substrate) often associated with homonymous lower visual field loss. We, here, describe five children (four males, one female; mean age 7.4 years, [range 4−11 years]; birth weight ≤ 2.5 kg; four were born ≤ 36 weeks of gestational age and one at 40 weeks) who presented to the Cerebral Visual Impairment Clinic at a tertiary care center in South India with clinical features remarkably consistent with the above description. In all children neuroimaging showed bilateral parietooccipital gliosis with regional white matter volume loss and focal callosal thinning, consistent with perinatal hypoxic ischemic encephalopathy and possible neonatal hypoglycemia.

Corresponding Ganglion Cell Atrophy in Patients With Postgeniculate Homonymous Visual Field Loss.

The goal of our study was to look for the presence of homonymous ganglion cell layer-inner plexiform layer complex (GCL-IPL) thinning using spectral-domain optical coherence tomography (SD-OCT) in patients with a history of adult-onset injury to the postgeniculate pathways with rigorous radiological exclusion of geniculate and pregeniculate pathology. We performed a retrospective review of twenty-two patients (ages 24-75 y, 6 men, 16 women) with homonymous visual field (VF) defects secondary to postgeniculate injury examining the GCL-IPL with SD-OCT. An additional fifteen patients (ages 28-85 y, 5 men, 10 women) with no visual pathway pathology served as controls. Using segmentation analysis software applied to the macular scan, a normalized asymmetry score was calculated for each eye comparing GCL-IPL thickness ipsilateral vs contralateral to the patient's brain lesions. We found that 15 of the twenty-two subjects had a relative thinning of the GCL-IPL ipsilateral to the postgeniculate lesion in both eyes (represented by a positive normalized asymmetry score in both eyes), whereas a similar pattern of right/left asymmetry was found in 4 controls (P = 0.0498). The magnitude of asymmetry was much greater in subjects compared with controls (P = 0.0004). There was no association between the degree of GCL-IPL thinning and the mean deviation on automated VF testing. A moderate correlation (R = 0.782, P = 0.004) between the magnitude of thinning and latency from onset of retrogeniculate injury was observed only after excluding patients beyond a cutoff point of 150 months. This data provides compelling new evidence of retrograde transsynaptic degeneration causing retinal ganglion cell loss after postgeniculate visual pathway injury.

Driving with homonymous visual field loss: Does visual search performance predict hazard detection?

Introduction Stroke often causes homonymous visual field loss, which can lead to exclusion from driving. Retention of a driving licence is sometimes possible by completing an on-road assessment, but this is not practical for all. It is important to find simple tests that can inform the assessment and rehabilitation of driving-related visual-motor function. Method We developed novel computerised assessments: visual search; simple reaction and decision reaction to appearing pedestrians; and pedestrian detection during simulated driving. We tested 12 patients with stroke (seven left, five right field loss) and 12 controls. Results The homonymous visual field defect group was split into adequately compensated or inadequately compensated groups based on visual search performance. The inadequately compensated group had problems with stimuli in their affected field: they tended to react more slowly than controls and in the driving task they failed to detect a number of pedestrians. In contrast, the adequately compensated group were better at detecting pedestrians, though reaction times were slightly slower than controls. Conclusion We suggest that our search task can predict, to a limited extent, whether a person with stroke compensates for visual field loss, and may potentially identify suitability for specific rehabilitation to promote return to driving.

Homonymous Visual Field Loss and Its Impact on Visual Exploration: A Supermarket Study.

Homonymous visual field defects (HVFDs) may critically interfere with quality of life. The aim of this study was to assess the impact of HVFDs on a supermarket search task and to investigate the influence of visual search on task performance. Ten patients with HVFDs (four with a right-sided [HR] and six with a left-sided defect [HL]), and 10 healthy-sighted, sex-, and age-matched control subjects were asked to collect 20 products placed on two supermarket shelves as quickly as possible. Task performance was rated as "passed" or "failed" with regard to the time per correctly collected item (TC -failed = 4.84 seconds based on the performance of healthy subjects). Eye movements were analyzed regarding the horizontal gaze activity, glance frequency, and glance proportion for different VF areas. Seven of 10 HVFD patients (three HR, four HL) passed the supermarket search task. Patients who passed needed significantly less time per correctly collected item and looked more frequently toward the VFD area than patients who failed. HL patients who passed the test showed a higher percentage of glances beyond the 60° VF (P < 0.05). A considerable number of HVFD patients performed successfully and could compensate for the HVFD by shifting the gaze toward the peripheral VF and the VFD area. These findings provide new insights on gaze adaptations in patients with HVFDs during activities of daily living and will enhance the design and development of realistic examination tools for use in the clinical setting to improve daily functioning. (http://www.clinicaltrials.gov, NCT01372319, NCT01372332).

Driving with Binocular Visual Field Loss? A Study on a Supervised On-Road Parcours with Simultaneous Eye and Head Tracking

Post-chiasmal visual pathway lesions and glaucomatous optic neuropathy cause binocular visual field defects (VFDs) that may critically interfere with quality of life and driving licensure. The aims of this study were (i) to assess the on-road driving performance of patients suffering from binocular visual field loss using a dual-brake vehicle, and (ii) to investigate the related compensatory mechanisms. A driving instructor, blinded to the participants' diagnosis, rated the driving performance (passed/failed) of ten patients with homonymous visual field defects (HP), including four patients with right (HR) and six patients with left homonymous visual field defects (HL), ten glaucoma patients (GP), and twenty age and gender-related ophthalmologically healthy control subjects (C) during a 40-minute driving task on a pre-specified public on-road parcours. In order to investigate the subjects' visual exploration ability, eye movements were recorded by means of a mobile eye tracker. Two additional cameras were used to monitor the driving scene and record head and shoulder movements. Thus this study is novel as a quantitative assessment of eye movements and an additional evaluation of head and shoulder was performed. Six out of ten HP and four out of ten GP were rated as fit to drive by the driving instructor, despite their binocular visual field loss. Three out of 20 control subjects failed the on-road assessment. The extent of the visual field defect was of minor importance with regard to the driving performance. The site of the homonymous visual field defect (HVFD) critically interfered with the driving ability: all failed HP subjects suffered from left homonymous visual field loss (HL) due to right hemispheric lesions. Patients who failed the driving assessment had mainly difficulties with lane keeping and gap judgment ability. Patients who passed the test displayed different exploration patterns than those who failed. Patients who passed focused longer on the central area of the visual field than patients who failed the test. In addition, patients who passed the test performed more glances towards the area of their visual field defect. In conclusion, our findings support the hypothesis that the extent of visual field per se cannot predict driving fitness, because some patients with HVFDs and advanced glaucoma can compensate for their deficit by effective visual scanning. Head movements appeared to be superior to eye and shoulder movements in predicting the outcome of the driving test under the present study scenario.