Toward Improving the Mobility of Patients with Peripheral Visual Field Defects with Novel Digital Spectacles

Advanced Visualization Engineering for Vision Disorders: A Clinically Focused Guide to Current Technology and Future Applications

Head-mounted visualization technology, often in the form of virtual, augmented, and mixed reality (VAMR), has revolutionized how visual disorders may be approached clinically. In this manuscript, we review the available literature on VAMR for visual disorders and provide a clinically oriented guide to how VAMR technology has been deployed for visual impairments. The chief areas of clinical investigation with VAMR are divided include (1) vision assessment, (2) vision simulation, and (3) vision rehabilitation. We discuss in-depth the current literature of these areas in VAMR and upcoming/future applications to combat the detrimental impact of visual impairment worldwide.

The use of augmented reality and virtual reality for visual field expansion and visual acuity improvement in low vision rehabilitation: a systematic review

INTRODUCTION

Developments in image processing techniques and display technology have led to the emergence of augmented reality (AR) and virtual reality (VR)-based low vision devices (LVDs). However, their promise and limitations in low vision rehabilitation are poorly understood. The objective of this systematic review is to appraise the application of AR/VR LVDs aimed at visual field expansion and visual acuity improvement in low vision rehabilitation.

METHODS

A systematic search of the literature was performed using MEDLINE, Embase, PsychInfo, HealthStar, and National Library of Medicine (PubMed) from inception to March 6, 2022. Articles were eligible if they included an AR or VR LVD tested on a sample of individuals with low vision and provided visual outcomes such as visual acuity, visual fields, and object recognition.

RESULTS

Of the 652 articles identified, 16 studies comprising 382 individuals with a mean age of 52.17 (SD = 18.30) years, and with heterogeneous low vision etiologies (i.e., glaucoma, age-related macular degeneration, retinitis pigmentosa) were included in this systematic review. Most articles used AR (53%), VR (40%), and one article used both AR and VR. The main visual outcomes evaluated were visual fields (67%), visual acuity (65%), and contrast sensitivity (27%). Various visual enhancement techniques were employed including variable magnification using digital zoom (67%), contrast enhancements (53%), and minification (27%). AR LVDs were reported to expand the visual field from threefold to ninefold. On average, individuals using AR/VR LVDs experienced an improved in visual acuity from 0.9 to 0.2 logMAR. Ten articles were classified as high or moderate risk of bias.

CONCLUSION

AR/VR LVDs were found to afford visual field expansion and visual acuity improvement in low vision populations. Even though the results of this review are promising, the lack of controlled studies with well-defined populations, use of small, convenience samples, and incomplete reporting of inclusion and exclusion criteria among included studies makes it challenging to judge the true impact of these devices. Future studies should address these limitations and compare various AR/LVDs to determine what is the ideal LVD type and vision enhancement combination based on the user's level of visual ability and lifestyle.

Development of Virtual Reality Walking Collision Detection Test on Head-mounted display

Detecting and avoiding collisions during walking is critical for safe mobility. To determine the effectiveness of clinical interventions, a realistic objective outcome measure is needed. A real-world obstacle course with moving hazards has numerous limitations (e.g., safety concerns of physical collision, inability to control events, maintaining event consistency, and event randomization). Virtual reality (VR) platforms may overcome such limitations. We developed a VR walking collision detection test using a standalone head-mounted display (HMD, Meta Quest 2) with the Unity 3D engine to enable subjects' physical walking within a VR environment (i.e., a busy shopping mall). The performance measures focus on the detection and avoidance of potential collisions, where a pedestrian may (or may not) walks toward a collision with the subject, while various non-colliding pedestrians are presented simultaneously. The physical space required for the system was minimized. During the development, we addressed expected and unexpected hurdles, such as mismatch of visual perception of VR space, limited field of view (FOV) afforded by the HMD, design of pedestrian paths, design of the subject task, handling of subject's response (detection or avoidance behavior), use of mixed reality (MR) for walking path calibration. We report the initial implementation of the HMD VR walking collision detection and avoidance scenarios that showed promising potential as clinical outcome measures.

Can Tele-Neuro-Ophthalmology Be Useful Beyond the Pandemic?

PURPOSE OF THE REVIEW

Neuro-ophthalmologists rapidly adopted telehealth during the COVID-19 pandemic to minimize disruption to patient care. This article reviews recent research on tele-neuro-ophthalmology adoption, current limitations, and potential use beyond the pandemic. The review considers how digital transformation, including machine learning and augmented reality, may be applied to future iterations of tele-neuro-ophthalmology.

RECENT FINDINGS

Telehealth utilization has been sustained among neuro-ophthalmologists throughout the pandemic. Adoption of tele-neuro-ophthalmology may provide solutions to subspecialty workforce shortage, patient access, physician wellness, and trainee educational needs within the field of neuro-ophthalmology. Digital transformation technologies have the potential to augment tele-neuro-ophthalmology care delivery by providing automated workflow solutions, home-based visual testing and therapies, and trainee education via simulators. Tele-neuro-ophthalmology use has and will continue beyond the COVID-19 pandemic. Digital transformation technologies, when applied to telehealth, will drive and revolutionize the next phase of tele-neuro-ophthalmology adoption and use in the years to come.

Design of Smart Head–Mounted Display Technology: A Convergent Mixed-Methods Study

Introduction: The purpose of this study was to characterize functional impairments and human factor considerations that affect perceptions and preferences for head-mounted display (HMD) technology for adults with low vision and chronic eye disease. Methods: Through a convergent mixed-methods design, participants with visual impairments (age-related macular degeneration, diabetic retinopathy, glaucoma, or retinitis pigmentosa) were recruited. Participants completed the Impact of Vision Impairment (IVI) questionnaire, used commercially available HMDs (eSight, NuEyes, and Epson Moverio), and were interviewed. The IVI was used to identify groups with low, moderate, and high vision–related quality of life (VRQOL). Transcribed interviews were analyzed using a thematic approach. The survey and qualitative findings were integrated using mixed-methods joint display analysis. Results: Twenty-one participants were enrolled (mean age of 58.2 years, 57% male, median Snellen acuity of 20/40 [range: 20/20–hand movement]). An equal number ( n = 9) expressed a preference for eSight and NuEyes, while ( n = 3) preferred the Moverio. Participants emphasized ease of use, including HMD controls and screen, as common reasons for preference. Those with lower IVI well-being scores preferred eSight due to vision improvement. Those with moderate IVI well-being scores preferred NuEyes due to comfort and size. Those with high IVI well-being scores cited usability as the most important feature. Discussion: User preferences for HMD features were associated with VRQOL. A mixed-methods approach explained how varying degrees of visual impairment and HMD preferences were qualitatively related to usability at the individual level. Implications for Practitioners: To increase acceptance, new HMD development for low vision should focus on performance, usability, and human factors engineering. Although HMD technology can benefit individuals with low vision, device features and functions vary in meaningful ways based on vision parameters. Practitioners should be aware of how patient and device variations influence preferences when they recommend wearable systems and optimize training to harness these systems.

Metaverse and Virtual Health Care in Ophthalmology: Opportunities and Challenges

ABSTRACT

The outbreak of the coronavirus disease 2019 has further increased the urgent need for digital transformation within the health care settings, with the use of artificial intelligence/deep learning, internet of things, telecommunication network/virtual platform, and blockchain. The recent advent of metaverse, an interconnected online universe, with the synergistic combination of augmented, virtual, and mixed reality described several years ago, presents a new era of immersive and real-time experiences to enhance human-to-human social interaction and connection. In health care and ophthalmology, the creation of virtual environment with three-dimensional (3D) space and avatar, could be particularly useful in patient-fronting platforms (eg, telemedicine platforms), operational uses (eg, meeting organization), digital education (eg, simulated medical and surgical education), diagnostics, and therapeutics. On the other hand, the implementation and adoption of these emerging virtual health care technologies will require multipronged approaches to ensure interoperability with real-world virtual clinical settings, user-friendliness of the technologies and clinical efficiencies while complying to the clinical, health economics, regulatory, and cybersecurity standards. To serve the urgent need, it is important for the eye community to continue to innovate, invent, adapt, and harness the unique abilities of virtual health care technology to provide better eye care worldwide.

Rehabilitation of visual perception in cortical blindness

Blindness is a common sequela after stroke affecting the primary visual cortex, presenting as a contralesional, homonymous, visual field cut. This can occur unilaterally or, less commonly, bilaterally. While it has been widely assumed that after a brief period of spontaneous improvement, vision loss becomes stable and permanent, accumulating data show that visual training can recover some of the vision loss, even long after the stroke. Here, we review the different approaches to rehabilitation employed in adult-onset cortical blindness (CB), focusing on visual restoration methods. Most of this work was conducted in chronic stroke patients, partially restoring visual discrimination and luminance detection. However, to achieve this, patients had to train for extended periods (usually many months), and the vision restored was not entirely normal. Several adjuvants to training such as noninvasive, transcranial brain stimulation, and pharmacology are starting to be investigated for their potential to increase the efficacy of training in CB patients. However, these approaches are still exploratory and require considerably more research before being adopted. Nonetheless, having established that the adult visual system retains the capacity for restorative plasticity, attention recently turned toward the subacute poststroke period. Drawing inspiration from sensorimotor stroke rehabilitation, visual training was recently attempted for the first time in subacute poststroke patients. It improved vision faster, over larger portions of the blind field, and for a larger number of visual discrimination abilities than identical training initiated more than 6 months poststroke (i.e., in the chronic period). In conclusion, evidence now suggests that visual neuroplasticity after occipital stroke can be reliably recruited by a range of visual training approaches. In addition, it appears that poststroke visual plasticity is dynamic, with a critical window of opportunity in the early postdamage period to attain more rapid, more extensive recovery of a larger set of visual perceptual abilities.

Augmented Reality in Ophthalmology: Applications and Challenges

Augmented reality (AR) has been developed rapidly and implemented in many fields such as medicine, maintenance, and cultural heritage. Unlike other specialties, ophthalmology connects closely with AR since most AR systems are based on vision systems. Here we summarize the applications and challenges of AR in ophthalmology and provide insights for further research. Firstly, we illustrate the structure of the standard AR system and present essential hardware. Secondly, we systematically introduce applications of AR in ophthalmology, including therapy, education, and clinical assistance. To conclude, there is still a large room for development, which needs researchers to pay more effort. Applications in diagnosis and protection might be worth exploring. Although the obstacles of hardware restrict the development of AR in ophthalmology at present, the AR will realize its potential and play an important role in ophthalmology in the future with the rapidly developing technology and more in-depth research.

Validity and reliability of eye tracking for visual acuity assessment in children with cortical visual impairment

BACKGROUND

Cortical visual impairment (CVI) is the leading cause of pediatric visual impairment in developed countries, but there is currently no evidence-based treatment. A method of visual assessment that captures multiple domains of visual functioning may facilitate evaluation of proposed therapies. We have developed an eye-tracking protocol that evaluates afferent, efferent, and higher-order visual parameters in children with CVI. We report its validity and reliability in assessing visual acuity.

METHODS

We recruited 16 children with CVI between the ages of 12 months and 12 years. Visual acuity was assessed clinically using a previously published six-level scale of visual behavior. Grating acuity was assessed by eye tracking using forced-choice preferential looking, which was performed at baseline and 1 month for reliability testing. Validity was assessed by correlating clinical acuity with grating acuity by eye tracking.

RESULTS

Clinical visual acuity ranged from 3 to 6 on the six-level scale, and grating acuity ranged from 0.25 to 20 cycles per degree (logMAR 0.18-2.08). There was strong correlation between grating acuity by eye tracking and clinical acuity assessment (ρ = -0.82; P = 0.0002). Test-retest reliability was excellent, with an intraclass correlation coefficient of 0.96 (95% CI, 0.88-0.99).

CONCLUSIONS

Eye tracking demonstrates excellent reliability for visual acuity assessment and high correlation with clinical assessment of visual acuity in pediatric CVI. Future research is necessary to determine whether eye tracking can assess other visual and oculomotor parameters in children with CVI, a prerequisite for incorporating this technique into future clinical trials and patient care.

Applications of Extended Reality in Ophthalmology: Systematic Review

BACKGROUND

Virtual reality, augmented reality, and mixed reality make use of a variety of different software and hardware, but they share three main characteristics: immersion, presence, and interaction. The umbrella term for technologies with these characteristics is extended reality. The ability of extended reality to create environments that are otherwise impossible in the real world has practical implications in the medical discipline. In ophthalmology, virtual reality simulators have become increasingly popular as tools for surgical education. Recent developments have also explored diagnostic and therapeutic uses in ophthalmology.

OBJECTIVE

This systematic review aims to identify and investigate the utility of extended reality in ophthalmic education, diagnostics, and therapeutics.

METHODS

A literature search was conducted using PubMed, Embase, and Cochrane Register of Controlled Trials. Publications from January 1, 1956 to April 15, 2020 were included. Inclusion criteria were studies evaluating the use of extended reality in ophthalmic education, diagnostics, and therapeutics. Eligible studies were evaluated using the Oxford Centre for Evidence-Based Medicine levels of evidence. Relevant studies were also evaluated using a validity framework. Findings and relevant data from the studies were extracted, evaluated, and compared to determine the utility of extended reality in ophthalmology.

RESULTS

We identified 12,490 unique records in our literature search; 87 met final eligibility criteria, comprising studies that evaluated the use of extended reality in education (n=54), diagnostics (n=5), and therapeutics (n=28). Of these, 79 studies (91%) achieved evidence levels in the range 2b to 4, indicating poor quality. Only 2 (9%) out of 22 relevant studies addressed all 5 sources of validity evidence. In education, we found that ophthalmic surgical simulators demonstrated efficacy and validity in improving surgical performance and reducing complication rates. Ophthalmoscopy simulators demonstrated efficacy and validity evidence in improving ophthalmoscopy skills in the clinical setting. In diagnostics, studies demonstrated proof-of-concept in presenting ocular imaging data on extended reality platforms and validity in assessing the function of patients with ophthalmic diseases. In therapeutics, heads-up surgical systems had similar complication rates, procedural success rates, and outcomes in comparison with conventional ophthalmic surgery.

CONCLUSIONS

Extended reality has promising areas of application in ophthalmology, but additional high-quality comparative studies are needed to assess their roles among incumbent methods of ophthalmic education, diagnostics, and therapeutics.

Virtual Reality and Augmented Reality in Ophthalmology: A Contemporary Prospective

PURPOSE

Most published systematic reviews have focused on the use of virtual reality (VR)/augmented reality (AR) technology in ophthalmology as it relates to surgical training. To date, this is the first review that investigates the current state of VR/AR technology applied more broadly to the entire field of ophthalmology.

METHODS

PubMed, Embase, and CINAHL databases were searched systematically from January 2014 through December 1, 2020. Studies that discussed VR and/or AR as it relates to the field of ophthalmology and provided information on the technology used were considered. Abstracts, non-peer-reviewed literature, review articles, studies that reported only qualitative data, and studies without English translations were excluded.

RESULTS

A total of 77 studies were included in this review. Of these, 28 evaluated the use of VR/AR in ophthalmic surgical training/assessment and guidance, 7 in clinical training, 23 in diagnosis/screening, and 19 in treatment/therapy. 15 studies used AR, 61 used VR, and 1 used both. Most studies focused on the validity and usability of novel technologies.

CONCLUSIONS

Ophthalmology is a field of medicine that is well suited for the use of VR/AR. However, further longitudinal studies examining the practical feasibility, efficacy, and safety of such novel technologies, the cost-effectiveness, and medical/legal considerations are still needed. We believe that time will indeed foster further technological advances and lead to widespread use of VR/AR in routine ophthalmic practice.

Mobility improvement of patients with peripheral visual field losses using novel see-through digital spectacles

PURPOSE

To evaluate see-through Augmented Reality Digital spectacles (AR DSpecs) for improving the mobility of patients with peripheral visual field (VF) losses when tested on a walking track.

DESIGN

Prospective Case Series.

PARTICIPANTS

21 patients with peripheral VF defects in both eyes, with the physical ability to walk without assistance.

METHODS

We developed the AR DSpecs as a wearable VF aid with an augmented reality platform. Image remapping algorithms produced personalized visual augmentation in real time based on the measured binocular VF with the AR DSpecs calibration mode. We tested the device on a walking track to determine if patients could more accurately identify peripheral objects.

MAIN OUTCOME MEASURES

We analyzed walking track scores (number of recognized/avoided objects) and eye tracking data (six gaze parameters) to measure changes in the kinematic and eye scanning behaviors while walking, and assessed a possible placebo effect by deactivating the AR DSpecs remapping algorithms in random trials.

RESULTS

Performance, judged by the object detection scores, improved with the AR DSpecs (P<0.001, Wilcoxon rank sum test) with an average improvement rate of 18.81%. Two gaze parameters improved with the activated algorithm (P<0.01, paired t-test), indicating a more directed gaze on the central path with less eye scanning. Determination of the binocular integrated VF with the DSpecs correlated with the integrated standard automated perimetry (R = 0.86, P<0.001), mean sensitivity difference 0.8 ± 2.25 dB (Bland-Altman).

CONCLUSIONS

AR DSpecs may improve walking maneuverability of patients with peripheral VF defects by enhancing detection of objects in a testing environment.