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

Abstract

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.

Appendices

Appendix 1

Search strategy used to survey databases

		MEDLINE OVID	EMBASE	PsychInfo	OVID Healthstar
#	Search	Results	Results	Results	Results
1	augmented reality.mp. or exp Augmented Reality/	3282	3939	1131	1819
2	virtual reality.mp. or exp Virtual Reality/	14,636	27,299	12,350	9472
3	mixed reality.mp	605	689	230	319
4	(augmented environment or virtual environment or augmented object).mp. or exp Imaging, Three-Dimensional/ or 3D object.mp	91,382	117,763	3424	83,661
5	(retinal imaging laser or Head mounted display).mp. or exp Smart Glasses/ or HMD.mp. or exp Self-Help Devices/ or eSight.mp. or HTC vive.mp	14,453	5162	582	13,036
6	(samsung gear or rendering engine or oculus or smartphone or tablet or smart device or sensory substitution or assistive technology or retinal prosth* or computer accommodation system or computer vision or electronic travel aid or wearable or object recognition or object detection or human computer interaction or oxSight or electronic glasses or Google glass* or ARIANNA + or Aira or user computer interface or computer assisted image processing).mp. or exp computer-assisted instruction/ or exp user-computer interface/ or exp image processing, computer-assisted/ or computer simulation.mp. or exp sensory aids	586,110	540,143	74,876	456,036
7	retinal prosthesis.mp. or exp Visual Prosthesis/	892	3018	510	627
8	exp Eye, Artificial/	1862	518	0	1668
9	low vision.mp. or exp Vision, Low/ or blind.mp. or exp Blidness, Cortical/ or exp Blindness/ or retinal disease.mp. or exp Retinal Diseases/ or exp Diabetic Retinopathy/ or exp Vision Disorders/ or visual impairment.mp. or exp Optic Atrophy, Hereditary, Leber/ or macular degeneration.mp. or exp Retinal degeneration/ or exp Macular Degeneration/ or exp Scotoma/ or exp Vision, Low/ or sight loss.mp. or exp Vision Disorders/	500,468	917,731	65,533	377,145
10	exp Optic Nerve Diseases/ or exp Glaucoma/ exp Visually Impaired Persons	89,218	180,383	510	50,637
11	exp Spatial Navigation or navigation.mp or exp mobility limitation or mobility.mp or wayfinding.mp or contrast enhancement.mp or edge enhancement.mp or exp color perception or colour enhancement.mp or colour enhancement.mp or colour filter.mp or color filter.mp or exp visual acuity or acuity.mp or exp gait or exp gait disorders, neurologic or obstacle avoidance.mp or obstacle detection.mp or exp postural balance or balance.mp or exp haptic technology or exp touch perception or tactile grahics.mp or accessibility.mp or exp vision, binocular or exp astigmatism or exp refractive errors or exp visual acuity or exp myopia or exp refraction, ocular or exp spatial behavior or exp orientation or visual rehabilitation.mp or collision detection.mp	903,795	1,303,403	142,572	510,382
12	1 or 2 or 3 or 4	106,376	144,163	13,898	92,813
13	5 or 6 or 7 or 8	599,187	546,179	75,267	467,550
14	9 or 10	568,880	1,028,295	65,533	414,479
15	11 AND 12 AND 13 AND 14	337	249	38	322

PubMed

(“augmented reality” OR AR OR “virtual reality” OR VR OR “mixed reality” OR “augmented environment” OR “virtual environment” OR “augmented object” OR “virtual object”) AND (“retinal imaging laser” OR “Head mounted display” OR HMD OR “smart glass*” OR “self-help device*” OR “eSight” OR “HTC vive” OR “samsung gear” OR “rendering engine” OR “oculus” OR “smartphone” OR “tablet” OR “smart device” OR “sensory substitution” OR “assistive technology” OR “retinal prosth*” OR “computer accommodation system” OR “computer vision” OR “electronic travel aid” OR “wearable” OR “human computer interaction” OR “oxSight” OR “electronic glasses” OR “Google glass*” OR “ARIANNA + ” OR “Aira” OR “user computer interface” OR “computer assisted image processing” OR “computer-assisted instruction” OR “user-computer interface” OR “computer-assisted” OR “computer simulation” OR “sensory aids” OR “retinal prosthesis” OR “Visual Prosthesis” OR “artificial eye”) AND (“low vision” OR “blind*” OR “blindness” OR “retinal disease” OR “retina” OR “diabetic retinopathy” OR “optic neuropathy” OR “vision disorder*” OR “visual impairment” OR “retinal degeneration” OR “scotoma” OR “sight loss” OR “macular degeneration” OR “macular” OR “foveal” OR “vision disorders” OR “optic nerve disease” OR “glaucoma” OR “visually impaired”) AND (“spatial navigation” OR navigation OR mobility OR wayfinding OR “contrast enhancement” OR “edge enhancement” OR “colour filter” OR “visual acuity” OR “acuity” OR “gait” OR “obstacle” OR balance OR haptic OR “touch perception” OR “tactile graphics” OR accessibility OR “binocular vision” OR “monocular vision” OR “astigmatism” OR refractive OR myopia OR “spatial behavior” OR orientation OR “visual rehabilitation” OR “vision rehabilitation” OR “collision detection”).

Appendix 2

Assessment of risk of bias and quality of included studies based on criteria from Joanna Briggs Institute Critical Appraisal Tools. For each article, JBI criteria questions were noted as “yes,” “no,” “unclear,” or “not applicable.” Studies that reached up to 49% of questions as “yes” were classified as high risk of bias; from 50 to 69% as moderate ROB; and more than 70% as low ROB