Visual field improvement in neglect after virtual reality intervention: a case study

Mapping Intimacies ◽

10.1101/2021.05.04.21256247 ◽

2021 ◽

Author(s):

Michael Christian Leitner ◽

Stefan Hawelka

Keyword(s):

Virtual Reality ◽

Visual Field ◽

Eye Tracking ◽

Bright Light ◽

Self Report ◽

Field Analysis ◽

Visual Field Defects ◽

Visual Neglect ◽

Self Evaluation ◽

Cortical Areas

Objective. Studies on neuropsychological rehabilitation of visual field defects provide an inconsistent picture regarding the effectiveness of so-called "restorative approaches" in visual field recovery (VFR). During a current research project on the clinical evaluation of VFR - in combination with head mounted virtual reality displays (HMD) - a patient ("Patient 7") suffering from visual neglect was investigated. Although the concept of VFR is originally not intended for patients suffering from higher cortical regions (as in neglect), we hypothesized that due to the strong attention-demanding training situation in HMDs, neglect patients might benefit from these intervention procedures based on restorative approaches. Methods and Analysis. Patient 7 was examined perimetrically using a "Humphrey Field Analyzer", "Goldmann Perimetry" and our newly developed and validated eye-tracking supported perimetric methodology "Eye tracking based visual field analysis" (EFA). Based on these high resolution results from the EFA, the exact location of the transition area between intact and defect visual field of Patient 7 was assessed. Next, bright light stimuli were placed along this area in our newly developed HMD "Salzburg Visual Field Trainer" (SVFT). The aim was to stimulate neuroplasticity - according to the concept of restitutive approaches - in the corresponding cortical areas of the patient. Patient 7 trained with the SVFT for a time period of 254 days. In 6 appointments the objective and subjective rehabilitation progress was assessed. Results. Perimetric assessment with the EFA shows an expansion of Patient 7's visual field of 48.8% (left eye) and 36.8% (right eye) after 254 days of training with the SVFT. Individual areas in the patient's visual field show a visual improvement of approximately 5.5 to 10.5 degree of visual angle. Subjective self-report of Patient 7 additionally shows improvements in self-evaluation of up to 317% in visual field functionality compared to self-evaluation on the first assessment date. Conclusions. The results from Patient 7 indicate that patients suffering from visual neglect potentially benefit from a neuropsychological intervention with HMD based on the restorative concept of visual field recovery. However, further studies with large case numbers and a focus both on daily-life improvements and on a clear distinction between patients with lesions in earlier and higher cortical areas are needed to make empirically valid and generalizing statements about our findings.

Download Full-text

Eye-tracking-based visual field analysis (EFA): a reliable and precise perimetric methodology for the assessment of visual field defects

BMJ Open Ophthalmology ◽

10.1136/bmjophth-2019-000429 ◽

2021 ◽

Vol 6 (1) ◽

pp. e000429

Author(s):

Michael Christian Leitner ◽

Florian Hutzler ◽

Sarah Schuster ◽

Lorenzo Vignali ◽

Patrick Marvan ◽

...

Keyword(s):

Eye Movements ◽

Visual Field ◽

Eye Tracking ◽

Field Analysis ◽

Visual Field Defects ◽

Test Duration ◽

Automated Perimetry ◽

The Individual ◽

The Right ◽

Field Defects

ObjectiveSeveral studies report evidence for training-related neuroplasticity in the visual cortex, while other studies suggest that improvements simply reflect inadequate eye fixation control during perimetric prediagnostics and postdiagnostics.Methods and analysisTo improve diagnostics, a new eye-tracking-based methodology for visual field analysis (eye-tracking-based visual field analysis (EFA)) was developed. The EFA is based on static automated perimetry and additionally takes individual eye movements in real time into account and compensates for them. In the present study, an evaluation of the EFA with the help of blind spots of 58 healthy participants and the individual visual field defects of 23 clinical patients is provided. With the help of the EFA, optical coherence tomography, Goldmann perimetry and a Humphrey field analyser, these natural and acquired scotomas were diagnosed and the results were compared accordingly.ResultsThe EFA provides a SE of measurement of 0.38° for the right eye (OD) and 0.50° for the left eye (OS), leading to 0.44° of visual angle for both eyes (OU). Based on participants’ individual results, the EFA provides disattenuated correlation (validity) of 1.00 for both OD and OS. Results from patients suffering from cortical lesions and glaucoma further indicate that the EFA is capable of diagnosing acquired scotoma validly and is applicable for clinical use.ConclusionOutcomes indicate that the EFA is highly reliable and precise in diagnosing individual shape and location of scotoma and capable of recording changes of visual field defects (after intervention) with unprecedented precision. Test duration is comparable to established instruments and due to the high customisability of the EFA, assessment duration can be shortened by adapting the diagnostic procedure to the patients’ individual visual field characteristics. Therefore, the saccade-compensating methodology enables researchers and healthcare professionals to rule out eye movements as a source of inaccuracies in pre-, post-, and follow-up assessments.

Download Full-text

Computerized color perimetry in multiple sclerosis

Multiple Sclerosis Journal ◽

10.1177/135245859800400207 ◽

1998 ◽

Vol 4 (2) ◽

pp. 79-84 ◽

Cited By ~ 6

Author(s):

N Accornero ◽

S Rinalduzzi ◽

M Capozza ◽

E Millefiorini ◽

G C Filligoi ◽

...

Keyword(s):

Visual Field ◽

Statistical Difference ◽

Cost Effective ◽

Quantitative Information ◽

Field Analysis ◽

Visual Field Defects ◽

Highly Sensitive ◽

The Subject ◽

Color Perimetry ◽

Field Defects

Color visual field analysis has proven highly sensitive for early visual impairments diagnosis in MS, yet it has never attained widespread popularity usually because the procedure is difficult to standardize, the devices are costly, and the test is fatiguing. We propose a computerized procedure running on standard PC, cost effective, clonable, and easy handled. Two hundred and sixty-four colored patches subtending 18 angle of vision, with selected hues and low saturation levels are sequentially and randomly displayed on gray equiluminous background of the PC screen subtending 2486408 angle of vision. The subject is requested to press a switch at the perception of the stimulus. The output provides colored maps with quantitative information. Comparison between normals and a selected population of MS patients with no actual luminance visual field defects, showed high statistical difference.

Download Full-text

Self-Report in Functional Assessment of Low Vision

Journal of Visual Impairment & Blindness ◽

10.1177/0145482x9008400202 ◽

1990 ◽

Vol 84 (2) ◽

pp. 61-66 ◽

Cited By ~ 3

Author(s):

J.P. Szlyk ◽

A. Arditi ◽

P. Coffey Bucci ◽

D. Laderman

Keyword(s):

Visual Field ◽

Functional Assessment ◽

Visual Function ◽

Low Vision ◽

Self Report ◽

Visual Field Defects ◽

Clinical Screening ◽

Item Questionnaire ◽

Function Finding ◽

The Relationship

Previous research on the relationship between performance of complex tasks and low vision has offered few clear predictors of visual function. In some clinical, screening, and rehabilitation settings, access to measures of vision whose validity extends to the conditions of daily life is limited. The low vision individual may be uniquely qualified to report on such inaccessible performance situations. We have constructed a 57-item questionnaire, administered by interview, designed to predict performance in low vision patients with visual field defects, on four broad categories of visual function: finding, detecting, scanning, and tracking. The finding and detecting categories were further subdivided into subcategories of functional visual field (e.g., finding close, detecting close and above). Subjects rated their experienced degree of difficulty on a wide variety of common tasks which specifically demand these functions. Validity was assessed with 41 subjects. The present study suggests that self-report can be an effective predictor of function, especially in conjunction with clinical psychophysical techniques.

Download Full-text

Collision avoidance in persons with homonymous visual field defects under virtual reality conditions

Vision Research ◽

10.1016/j.visres.2011.10.019 ◽

2012 ◽

Vol 52 (1) ◽

pp. 20-30 ◽

Cited By ~ 18

Author(s):

Eleni Papageorgiou ◽

Gregor Hardiess ◽

Hermann Ackermann ◽

Horst Wiethoelter ◽

Klaus Dietz ◽

...

Keyword(s):

Virtual Reality ◽

Visual Field ◽

Collision Avoidance ◽

Visual Field Defects ◽

Field Defects

Download Full-text

Adaptation to Visual Field Defects with Virtual Reality Scotoma in Healthy Subjects

Current Oculomotor Research ◽

10.1007/978-1-4757-3054-8_12 ◽

1999 ◽

pp. 89-92 ◽

Cited By ~ 2

Author(s):

W. H. Zangemeister ◽

U. Oechsner

Keyword(s):

Virtual Reality ◽

Visual Field ◽

Healthy Subjects ◽

Visual Field Defects ◽

Field Defects

Download Full-text

Patients Prefer a Virtual Reality Approach Over a Similarly Performing Screen-Based Approach for Continuous Oculomotor-Based Screening of Glaucomatous and Neuro-Ophthalmological Visual Field Defects

Frontiers in Neuroscience ◽

10.3389/fnins.2021.745355 ◽

2021 ◽

Vol 15 ◽

Author(s):

Rijul Saurabh Soans ◽

Remco J. Renken ◽

James John ◽

Amit Bhongade ◽

Dharam Raj ◽

...

Keyword(s):

Virtual Reality ◽

Visual Field ◽

User Experience ◽

Original Method ◽

Tracking Task ◽

Visual Field Defects ◽

Automated Perimetry ◽

Eye Tracker ◽

Standard Automated Perimetry ◽

Field Defects

Standard automated perimetry (SAP) is the gold standard for evaluating the presence of visual field defects (VFDs). Nevertheless, it has requirements such as prolonged attention, stable fixation, and a need for a motor response that limit application in various patient groups. Therefore, a novel approach using eye movements (EMs) – as a complementary technique to SAP – was developed and tested in clinical settings by our group. However, the original method uses a screen-based eye-tracker which still requires participants to keep their chin and head stable. Virtual reality (VR) has shown much promise in ophthalmic diagnostics – especially in terms of freedom of head movement and precise control over experimental settings, besides being portable. In this study, we set out to see if patients can be screened for VFDs based on their EM in a VR-based framework and if they are comparable to the screen-based eyetracker. Moreover, we wanted to know if this framework can provide an effective and enjoyable user experience (UX) compared to our previous approach and the conventional SAP. Therefore, we first modified our method and implemented it on a VR head-mounted device with built-in eye tracking. Subsequently, 15 controls naïve to SAP, 15 patients with a neuro-ophthalmological disorder, and 15 glaucoma patients performed three tasks in a counterbalanced manner: (1) a visual tracking task on the VR headset while their EM was recorded, (2) the preceding tracking task but on a conventional screen-based eye tracker, and (3) SAP. We then quantified the spatio-temporal properties (STP) of the EM of each group using a cross-correlogram analysis. Finally, we evaluated the human–computer interaction (HCI) aspects of the participants in the three methods using a user-experience questionnaire. We find that: (1) the VR framework can distinguish the participants according to their oculomotor characteristics; (2) the STP of the VR framework are similar to those from the screen-based eye tracker; and (3) participants from all the groups found the VR-screening test to be the most attractive. Thus, we conclude that the EM-based approach implemented in VR can be a user-friendly and portable companion to complement existing perimetric techniques in ophthalmic clinics.

Download Full-text

Salzburg Visual Field Trainer (SVFT): A virtual reality device for (the evaluation of) neuropsychological rehabilitation

10.1101/2021.03.25.21254352 ◽

2021 ◽

Author(s):

Michael Christian Leitner ◽

Dirk Christoph Gütlin ◽

Stefan Hawelka

Keyword(s):

Virtual Reality ◽

Visual Field ◽

Predictive Value ◽

Visual Field Defects ◽

Neuropsychological Rehabilitation ◽

Hit Rate ◽

Neurological Patients ◽

The Individual ◽

Field Defects ◽

Blind Spots

AbstractObjectiveSo-called “Visual Restitution Therapies” (VRT) claim to ameliorate visual field defects of neurological patients by repeated visual light stimulation, leading to training-related neuroplasticity and resulting in reconnection of lesioned neurons in early cortical areas. Because existing systems are stationary, uncomfortable and unreliable, we developed a training instrument based on virtual reality goggles. The goal of the “Salzburg Visual Field Trainer” (SVFT) is twofold: (1) The device facilitates the clinical evaluation of established neuropsychological rehabilitation approaches, such as VRT. (2) The device enables patients to independently perform VRT based (or other) neuropsychological training methodologies flexibly, comfortably and reliably.Methods and AnalysisThe SVFT was developed on the principles of VRT. Individual configuration of the SVFT is based on perimetric data of the respective patient’s visual field. To validate the utmost important procedure in neuropsychological rehabilitation methodologies - that is displaying stimuli precisely in desired locations in the user’s visual field - two steps were conducted in this proof-of-concept study: First, we assessed the individual “blind spots” location and extent of 40 healthy, normal sighted participants. This was done with the help of our recently developed and validated perimetric methodology “Eye Tracking Based Visual Field Analysis” (EFA). Second, depending on the individual characteristics of every participant’s blind spots, we displayed - with the help of the SVFT - 15 stimuli in the respective locations of every participants’ blind spots and 85 stimuli in the surrounding, fully intact visual area. The ratio between visible and non-visible stimuli, which reflects in the documented behavioral response (clicks on a remote control) of the 40 participants, provides insight into the accuracy of the SVFT to display training stimuli in areas desired by the investigator. As the blind spot is a naturally occurring, absolute scotoma in human vision, we utilized this blind area as an objective criterion and a “simulated” visual field defect to evaluate the (technical) methodology of SVFT.ResultsOutcomes indicate that the SVFT and its methodology is highly accurate in displaying training stimuli in desired areas of the user’s visual field with an accuracy of 99.0%. Data analysis further shows a sensitivity of .980, specificity of .992, positive predictive value of .955, negative predictive value of .996, hit rate of .990, random hit rate of .742 and RATZ-Index of .976. This translates to 14.7% correct non-reactions, 0.7% false non-reactions, 0.3% false reactions and 84.3% correct reactions to displayed test stimuli during the evaluation study with the SVFT. Reports from participants further indicate that the SVFT is comfortable to wear and intuitive to use.ConclusionsThe SVFT can help to investigate the true effects of VRT based methodologies (or other neuropsychological approaches) and the underlying mechanisms of training-related neuroplasticity in early regions of the visual cortex in neurological patients suffering from visual field defects.

Download Full-text