Helping Blind People Grasp: Evaluating a Tactile Bracelet for Remotely Guiding Grasping Movements.

The problem of supporting visually impaired and blind people in meaningful interactions with objects is often neglected. To address this issue, we adapted a tactile belt for enhanced spatial navigation into a bracelet worn on the wrist that allows visually impaired people to grasp target objects. Participants' performance in locating and grasping target items when guided using the bracelet, which provides direction commands via vibrotactile signals, was compared to their performance when receiving auditory instructions. While participants were faster with the auditory commands, they also performed well with the bracelet, encouraging future development of this system and similar systems.

Rehabilitation of the Severely Visually Impaired and the Blind in a Developing Country.

Blind individuals whether from birth or after being sighted for different periods of their lives constitute about 1% of the Nigerian population. These are individuals who can meaningfully contribute to the growth and development of society if properly guided. However, the traditional way of thinking within the society they find themselves in contributes to their lack of productivity. From birth to adulthood, they need to be guided and consciously prepared for independence. This is not yet widely obtainable in Nigerian society and other developing societies and generally may result in rejection, neglect, and high mortality rates in those affected with the majority unemployed sometimes for up to 10-15 years. It is imperative to offer comprehensive rehabilitation services that can assist this group of individuals to assert/reassert control and independence by designing a program tailored to meet their individual needs (not forgetting those who become blind as adults). A regional center, The Lens Rehabilitation center for the blind and severely visually impaired (TLEC ReHab Nig) located in Port Harcourt, Nigeria has put together a comprehensive program to ensure all round preparedness for independent, productive and fruitful living for persons living with blindness in line with best practices. This is an initial report on the outcome.

Les aveugles, qu'ils soient nés ou qu'ils aient été voyants pendant différentes périodes de leur vie, constituent environ 1% de la population nigériane. Ce sont des personnes qui peuvent contribuer de manière significative à la croissance et au développement de la société si elles sont correctement guidées. Cependant, le mode de pensée traditionnel au sein de la société dans laquelle ils se trouvent assure en grande partie leur manque de productivité. De la naissance à l'âge adulte, ils doivent être traités et préparés consciemment à l'indépendance. Cela n'est pas encore possible dans la société nigériane et dans d'autres sociétés en développement et en général, cela peut entraîner le rejet, la négligence et des taux de mortalité élevés chez les personnes touchées, la majorité d'entre elles restant à la maison jusqu'à 10 ou 15 ans sans rien faire. Il est impératif d'offrir des services de réadaptation complets qui peuvent aider ce groupe d'individus à s'affirmer/réaffirmer leur contrôle et leur indépendance en concevant un programme adapté à leurs besoins individuels. leurs besoins individuels. Un centre régional, The Lens Rehabilitation center for the blind and severely visually impaired (TLEC ReHab Nig), situé à Port Harcourt, au Nigeria, a mis en place un programme complet visant à préparer les personnes atteintes de cécité à une vie indépendante, productive et fructueuse, conformément aux meilleures pratiques. Il s'agit d'un premier rapport sur les résultats obtenus. Mots clés: Aveugle, Éducation inclusive, Réhabilitation visuelle, Réhabilitation TLEC, Nigeria.

Telerehabilitation for people with low vision.

BACKGROUND: Low vision affects over 300 million people worldwide and can compromise both activities of daily living and quality of life. Rehabilitative training and vision assistive equipment (VAE) may help, but some visually impaired people have limited resources to attend in-person visits to rehabilitation clinics to be trained to learn to use VAE. These people may be able to overcome barriers to care through access to remote, internet-based consultation (telerehabilitation). OBJECTIVES: To compare the effects of telerehabilitation with face-to-face (e.g. in-office or inpatient) vision rehabilitation services for improving vision-related quality of life and near reading ability in people with visual function loss due to any ocular condition. Secondary objectives were to evaluate compliance with scheduled rehabilitation sessions, abandonment rates for VAE devices, and patient satisfaction ratings. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register) (2021, Issue 9); Ovid MEDLINE; Embase.com; PubMed; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any language restriction or study design filter in the electronic searches; however, we restricted the searches from 1980 onwards because the internet was not introduced to the public until 1982. We last searched CENTRAL, MEDLINE Ovid, Embase, and PubMed on 14 September 2021, and the trial registries on 16 March 2022. SELECTION CRITERIA: We included randomized controlled trials (RCTs) or controlled clinical trials (CCTs) in which participants diagnosed with low vision had received vision rehabilitation services remotely from a human provider using internet, web-based technology compared with an approach involving in-person consultations. DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles and abstracts retrieved by the searches of the electronic databases and then full-text articles for eligible studies. Two review authors independently abstracted data from the included studies. Any discrepancies were resolved by discussion. MAIN RESULTS: We identified one RCT/CCT that indirectly met our inclusion criteria, and two ongoing trials that met our inclusion criteria. The included trial had an overall high risk of bias. We did not conduct a quantitative analysis since multiple controlled trials were not identified.  The single included trial of 57 participants utilized a parallel-group design. It compared 30 hours of either personalized low vision training through telerehabilitation with a low vision therapist (the experimental group) with the self-training standard provided by eSight using the eSkills User Guide that was self-administered by the participants at home for one hour per day for 30 days (the comparison group). The trial investigators found a similar direction of effects for both groups for vision-related quality of life and satisfaction at two weeks, three months, and six months. A greater proportion of participants in the comparison group had abandoned or discontinued use of the eSight Eyewear at two weeks than those in the telerehabilitation group, but discontinuance rates were similar between groups at one month and three months. We rated the certainty of the evidence for all outcomes as very low due to high risk of bias in randomization processes and missing outcome data and imprecision.   AUTHORS' CONCLUSIONS: The included trial found similar efficacy between telerehabilitation with a therapist and an active control intervention of self-guided training in mostly younger to middle-aged adults with low vision who received a new wearable electronic aid. Given the disease burden and the growing interest in telemedicine, the two ongoing studies, when completed, may provide further evidence of the potential for telerehabilitation as a platform for providing services to people with low vision.

SILICONE OIL-FILLED FOLDABLE CAPSULAR VITREOUS BODY VERSUS SILICONE OIL ENDOTAMPONADE FOR TREATMENT OF NO LIGHT PERCEPTION AFTER SEVERE OCULAR TRAUMA.

PURPOSE: To compare the anatomical and functional outcomes of silicone oil (SO)-filled foldable capsular vitreous body (FCVB) and SO endotamponade in vitrectomy for patients with no light perception after ocular trauma. METHODS: A total of 64 patients (64 eyes) with no light perception caused by severe ocular trauma were divided into FCVB and SO groups based on the surgical treatment. The main outcome measurements were retinal reattachment rate, intraocular pressure, best-corrected visual acuity, and number of operations. RESULTS: Both the FCVB group (29 eyes) and the SO group (35 eyes) showed significant improvement in postoperative best-corrected visual acuity and intraocular pressure. The two groups showed no significant differences in final intraocular pressure and the retinal reattachment rate. The postoperative vision (≥LP) in the FCVB group was significantly worse than in the SO group (FCVB [4/29] vs. SO [18/35], P = 0.003). However, the number of surgeries in the FCVB group was significantly lower than in the SO group (FCVB [1.10] vs. SO [2.23], P < 0.001). CONCLUSION: Vitrectomy combined with SO endotamponade shows better short-term improvement in the treatment of no light perception caused by severe ocular trauma. However, SO-filled FCVB can effectively prevent many complications caused by direct SO endotamponade, such as secondary surgeries or SO dependence.

Enablers and barriers encountered by working-age and older adults with vision impairment who pursue braille training.

PURPOSE: We explored the experiences of working-age and older adults with acquired vision impairment who pursued braille rehabilitation training, and the facilitators and barriers they encountered throughout this process. METHODS: Semi-structured interviews of up to 90 min in length were conducted with 14 participants from across Canada who learned braille between the ages of 33 and 67 (Mdn = 46). Transcripts were analyzed by two researchers using interpretive phenomenological analysis. RESULTS: A variety of personal, social and institutional factors characterize the adult braille learning experience. Among these, participants highlight the role of prior identity and experience, the impact of access to resources and the cost of materials and devices needed to maintain braille skills. Findings also emphasize invisible barriers, including the role of societal perceptions towards braille, the level of support provided by family and friends, and the influence of unconscious biases towards braille and aging held by both adult learners and those around them. CONCLUSIONS: These findings provide important context to improve policies and practice in adult braille rehabilitation. As the prevalence of age-related vision impairment continues to increase, it will become imperative to understand the unique needs of working-age and older adults with acquired vision impairment who pursue braille.Implications for REHABILITATIONThis study is one of the first to explore the experiences of working-age and older adults with acquired visual impairment who pursue braille rehabilitation training.Rehabilitation professionals must take into account prior learning and reading experiences which may shape the braille learning process.Family members require greater access to resources and support during the training process.There is a significant need for public education to address societal misconceptions about braille and blindness that can lead to a reluctance to use braille.Interactions with other braille users foster more empowering definitions of braille that align with the social model understanding of disability.

Multimodal sensing and intuitive steering assistance improve navigation and mobility for people with impaired vision.

Globally, more than 250 million people have impaired vision and face challenges navigating outside their homes, affecting their independence, mental health, and physical health. Navigating unfamiliar routes is challenging for people with impaired vision because it may require avoiding obstacles, recognizing objects, and wayfinding indoors and outdoors. Existing approaches such as white canes, guide dogs, and electronic travel aids only tackle some of these challenges. Here, we present the Augmented Cane, a white cane with a comprehensive set of sensors and an intuitive feedback method to steer the user, which addresses navigation challenges and improves mobility for people with impaired vision. We compared the Augmented Cane with a white cane by having sighted and visually impaired participants complete navigation challenges while blindfolded: walking along hallways, avoiding obstacles, and following outdoor waypoints. Across all experiments, the Augmented Cane increased the walking speed for participants with impaired vision by 18 ± 7% and sighted participants by 35 ± 12% compared with a white cane. The increase in walking speed may be due to accurate steering assistance, reduced cognitive load, fewer contacts with the environment, and higher participant confidence. We also demonstrate advanced navigation capabilities of the Augmented Cane: indoor wayfinding, recognizing and steering the participant to a key object, and navigating a sequence of indoor and outdoor challenges. The open-source and low-cost design of the Augmented Cane provides a platform that may improve the mobility and quality of life of people with impaired vision.

Structure of variability in scanning movement predicts braille reading performance in children.

Among children learning to read braille, we asked whether the quantitative kinematics of scanning movements of the reading finger would be related to the proficiency of braille reading. Over a period of 12 months, we recorded the position and orientation of the reading fingers of eight congenitally or early blind children. We found that the strength of long-range power-law temporal correlations in the velocity fluctuations increased with performance in braille reading. In addition, we found that the variability of the angular orientation of the reading finger that affects the contact region on the fingerpad was negatively related to braille reading performance. These results confirm that the quantitative kinematics of finger scanning movements were related to functional performance in braille reading. The results add to the growing body of evidence that long-range temporal correlations in exploratory behavior can predict perceptual performance, and that scanning movements that center important tactile information on the small, high resolution area contribute to the pickup of information.

Psychological complexities of visual restoration.

In this paper, we report the psychological and emotional experience of a patient who regained vision after over a decade of vision loss. The negative psychological implications of blindness are well recognised and there is a robust link between visual impairment and low mood and depressive symptoms. Although uncommon, low mood and depressive symptoms have been reported in patients whose sight has been restored, and lack of research gives rise to the possibility their prevalence may be grossly under-recognised in such patient groups. The effects can be so severe that patients may revert to living in darkness in mimicry of their previous lifestyle, effectively obviating the sight-restoring surgery. Healthcare professionals have a responsibility to address this traditionally neglected need by facilitating social, psychological and medical interventions that may ease the return to vision.

Case Report: Effect of a Retinal Prosthesis System on Charles Bonnet Visual Hallucinations.

SIGNIFICANCE: Charles Bonnet syndrome is commonly encountered and diagnosed in low-vision patients. It can be distressing for some of them, as there is no known effective treatment of this condition. Although there is a growing interest in retinal implants for blind patients with severe retinal diseases, the effect of these devices on Charles Bonnet syndrome visual hallucinations remains undocumented. PURPOSE: The aim of this study was to report changes in the Charles Bonnet syndrome of a patient with retinitis pigmentosa after implantation of the Argus II retinal prosthesis. CASE REPORT: A 65-year-old patient with retinitis pigmentosa and no light perception was frequently experiencing Charles Bonnet syndrome. In the hope of improving his vision, he received an Argus II retinal prosthesis in 2018 and participated in a 10-week rehabilitation program at the Institut Nazareth et Louis-Braille. The nature and the frequency of his Charles Bonnet syndrome were documented with the Questionnaire de repérage du syndrome de Charles Bonnet (a French questionnaire used to screen for Charles Bonnet syndrome) before the surgery and for 70 weeks after it. The patient's visual acuity and visual fields were monitored during the same period. Additional tests were administered to document the visual, psychological, and cognitive states of the patient throughout the study. CONCLUSIONS: Although this case report confirmed that Argus II retinal prosthesis improves the performance of blind patients in visual tests, the improvement was not associated with a decrease in the symptoms of Charles Bonnet syndrome.

Maximizing Telerehabilitation for Patients With Visual Loss After Stroke: Interview and Focus Group Study With Stroke Survivors, Carers, and Occupational Therapists.

BACKGROUND: Visual field defects are a common consequence of stroke, and compensatory eye movement strategies have been identified as the most promising rehabilitation option. There has been a move toward compensatory telerehabilitation options, such as the Durham Reading and Exploration (DREX) training app, which significantly improves visual exploration, reading, and self-reported quality of life. OBJECTIVE: This study details an iterative process of liaising with stroke survivors, carers, and health care professionals to identify barriers and facilitators to using rehabilitation tools, as well as elements of good practice in telerehabilitation, with a focus on how the DREX package can be maximized. METHODS: Survey data from 75 stroke survivors informed 12 semistructured engagement activities (7 focus groups and 5 interviews) with 32 stroke survivors, 10 carers, and 24 occupational therapists. RESULTS: Thematic analysis identified key themes within the data. Themes identified problems associated with poststroke health care from both patients' and occupational therapists' perspectives that need to be addressed to improve uptake of this rehabilitation tool and telerehabilitation options generally. This included identifying additional materials or assistance that were required to boost the impact of training packages. The acute rehabilitation setting was an identified barrier, and perceptions of technology were considered a barrier by some but a facilitator by others. In addition, 4 key features of telerehabilitation were identified: additional materials, the importance of goal setting, repetition, and feedback. CONCLUSIONS: The data were used to try to overcome some barriers to the DREX training and are further discussed as considerations for telerehabilitation in general moving forward.

Helping the Blind to Get through COVID-19: Social Distancing Assistant Using Real-Time Semantic Segmentation on RGB-D Video.

The current COVID-19 pandemic is having a major impact on our daily lives. Social distancing is one of the measures that has been implemented with the aim of slowing the spread of the disease, but it is difficult for blind people to comply with this. In this paper, we present a system that helps blind people to maintain physical distance to other persons using a combination of RGB and depth cameras. We use a real-time semantic segmentation algorithm on the RGB camera to detect where persons are and use the depth camera to assess the distance to them; then, we provide audio feedback through bone-conducting headphones if a person is closer than 1.5 m. Our system warns the user only if persons are nearby but does not react to non-person objects such as walls, trees or doors; thus, it is not intrusive, and it is possible to use it in combination with other assistive devices. We have tested our prototype system on one blind and four blindfolded persons, and found that the system is precise, easy to use, and amounts to low cognitive load.

Lingual electrotactile discrimination ability is associated with the presence of specific connective tissue structures (papillae) on the tongue surface.

Electrical stimulation of nerve endings in the tongue can be used to communicate information to users and has been shown to be highly effective in sensory substitution applications. The anterior tip of the tongue has very small somatosensory receptive fields, comparable to those of the finger tips, allowing for precise two-point discrimination and high tactile sensitivity. However, perception of electrotactile stimuli varies significantly between users, and across the tongue surface. Despite this, previous studies all used uniform electrode grids to stimulate a region of the dorsal-medial tongue surface. In an effort to customize electrode layouts for individual users, and thus improve efficacy for sensory substitution applications, we investigated whether specific neuroanatomical and physiological features of the tongue are associated with enhanced ability to perceive active electrodes. Specifically, the study described here was designed to test whether fungiform papillae density and/or propylthiouracil sensitivity are positively or negatively associated with perceived intensity and/or discrimination ability for lingual electrotactile stimuli. Fungiform papillae number and distribution were determined for 15 participants and they were exposed to patterns of electrotactile stimulation (ETS) and asked to report perceived intensity and perceived number of stimuli. Fungiform papillae number and distribution were then compared to ETS characteristics using comprehensive and rigorous statistical analyses. Our results indicate that fungiform papillae density is correlated with enhanced discrimination ability for electrical stimuli. In contrast, papillae density, on average, is not correlated with perceived intensity of active electrodes. However, results for at least one participant suggest that further research is warranted. Our data indicate that propylthiouracil taster status is not related to ETS perceived intensity or discrimination ability. These data indicate that individuals with higher fungiform papillae number and density in the anterior medial tongue region may be better able to use lingual ETS for sensory substitution.

Navigation aid for blind persons by visual-to-auditory sensory substitution: A pilot study.

PURPOSE: In this study, we investigate to what degree augmented reality technology can be used to create and evaluate a visual-to-auditory sensory substitution device to improve the performance of blind persons in navigation and recognition tasks. METHODS: A sensory substitution algorithm that translates 3D visual information into audio feedback was designed. This algorithm was integrated in an augmented reality based mobile phone application. Using the mobile device as sensory substitution device, a study with blind participants (n = 7) was performed. The participants navigated through pseudo-randomized obstacle courses using either the sensory substitution device, a white cane or a combination of both. In a second task, virtual 3D objects and structures had to be identified by the participants using the same sensory substitution device. RESULTS: The realized application for mobile devices enabled participants to complete the navigation and object recognition tasks in an experimental environment already within the first trials without previous training. This demonstrates the general feasibility and low entry barrier of the designed sensory substitution algorithm. In direct comparison to the white cane, within the study duration of ten hours the sensory substitution device did not offer a statistically significant improvement in navigation.

Older adults with dual sensory loss in rehabilitation show high functioning and may fare better than those with single sensory loss.

The population of older adults that have Dual Sensory Loss (DSL) is increasing, yet most research to date has focused on single sensory impairment and is inconclusive as to whether DSL is associated with worse impact on health and well-being over single sensory loss. The primary aim of this study was to characterize the health and functioning of community-dwelling older adults with DSL who were receiving sensory rehabilitation, using an understudied assessment: the interRAI Community Health Assessment (CHA). The secondary aim was to investigate whether older adults with DSL had worse health-related outcomes than their peers with only vision loss (VL) or only hearing loss (HL). We report and compare the interRAI CHA results in a sample of 200 older adults (61+ years of age) who had DSL, VL or HL. Overall, all sensory impairment groups showed high functioning in the areas of cognition, communication, activities of daily living, depression, and psycho-social well-being. DSL was not always associated with worse outcomes compared to a single sensory loss. Rather, the results varied depending on the tasks assessed, as well as which groups were compared. Our findings highlight that despite the negative impact of sensory losses, community-dwelling older adults receiving sensory rehabilitation services tend to have overall good health and a high level of independence. These results also show that DSL is not always associated with worse outcomes compared to a single sensory loss. Further research is needed to better characterize older adults with DSL who have more severe sensory and cognitive difficulties than those in our sample, and among those who are not receiving rehabilitation services.

Neurolight: A Deep Learning Neural Interface for Cortical Visual Prostheses.

Visual neuroprosthesis, that provide electrical stimulation along several sites of the human visual system, constitute a potential tool for vision restoration for the blind. Scientific and technological progress in the fields of neural engineering and artificial vision comes with new theories and tools that, along with the dawn of modern artificial intelligence, constitute a promising framework for the further development of neurotechnology. In the framework of the development of a Cortical Visual Neuroprosthesis for the blind (CORTIVIS), we are now facing the challenge of developing not only computationally powerful tools and flexible approaches that will allow us to provide some degree of functional vision to individuals who are profoundly blind. In this work, we propose a general neuroprosthesis framework composed of several task-oriented and visual encoding modules. We address the development and implementation of computational models of the firing rates of retinal ganglion cells and design a tool - Neurolight - that allows these models to be interfaced with intracortical microelectrodes in order to create electrical stimulation patterns that can evoke useful perceptions. In addition, the developed framework allows the deployment of a diverse array of state-of-the-art deep-learning techniques for task-oriented and general image pre-processing, such as semantic segmentation and object detection in our system's pipeline. To the best of our knowledge, this constitutes the first deep-learning-based system designed to directly interface with the visual brain through an intracortical microelectrode array. We implement the complete pipeline, from obtaining a video stream to developing and deploying task-oriented deep-learning models and predictive models of retinal ganglion cells' encoding of visual inputs under the control of a neurostimulation device able to send electrical train pulses to a microelectrode array implanted at the visual cortex.

[Validation of the 13-30ARAMAV assessment, a new quality of life and autonomy questionnaire adapted to visually impaired patients]. / Validation du bilan 13­30ARAMAV, un nouveau questionnaire de qualité de vie et d'autonomie adapté aux patients déficients visuels.

PURPOSE: To evaluate the ARAMAV 13-30 questionnaire, a new autonomy and quality of life questionnaire developed for visually impaired patients. METHODS: We carried out a single-center prospective study at the ARAMAV institute in collaboration with the University Hospital of Nîmes. The patients included were admitted for low vision rehabilitation. Each patient received an occupational therapy assessment, the Short Forms 36 (SF36) quality of life questionnaire and the ARAMAV 13-30 questionnaire at the start and at the end of rehabilitation. We verified the reproducibility, the sensitivity to change, and internal and external consistency of the questionnaire. RESULTS: We included 231 patients over a period of 4 years. All the patients were blind or visually impaired. We observed excellent intra- and interuser reproducibility of the questionnaire, with a Lin coefficient>0.9 (0.99 and 0.91, respectively). By comparing the variations of the different scores between before and after low vision rehabilitation, we observed excellent sensitivity to change for both the autonomy and quality of life portions of the questionnaire. Finally, we observed excellent internal and external consistency. CONCLUSION: We therefore propose the ARAMAV 13-30 questionnaire as a new tool in evaluating autonomy and quality of life specifically in visually impaired patients, which may also be used to assess the effect of low vision rehabilitation.

Ultrasonic Echolocation Device for Assisting the Visually Impaired.

BACKGROUND: Echolocation is a technique whereby the location of objects is determined via reflected sound. Currently, some visually impaired individuals use a form of echolocation to locate objects and to orient themselves. However, this method takes years of practice to accurately utilize. AIMS: This paper presents the development of a sensory substitution device for visually impaired users, which gauged distances and the placement of objects. METHODS: Using ultrasonic technology, the device employed a method of echolocation to increase the user's independence and mobility. The main components of this device are an ultrasound transceiver and a miniaturized Arduino board. Through research and prototyping, this technology was integrated into a biomedical application in a watch form factor which provides feedback to the user regarding the measured distance by the ultrasonic transducer. RESULTS: The output of this process is a tactile feedback that varies in intensity proportional to the distance of the detected object. We tested the device in different scenarios including different distances from a different material. The difference between the device reading and the actual distance, from 0 to 400 cm was statistically insignificant. CONCLUSION: It is believed this device will boost the confidence of the user in navigation.

Surgical outcomes of macular hole and epimacular membrane treatment in patients with intraoperative amaurosis under sub-Tenon's anesthesia.

OBJECTIVE: Some patients have been found to develop intraoperative amaurosis under sub-Tenon's anesthesia. We explored whether these patients have poor surgical outcomes during mid- to long-term postoperative follow-up. METHODS: In this case series, 74 of 85 patients with macular diseases who underwent phacoemulsification combined with vitrectomy under sub-Tenon's anesthesia developed intraoperative amaurosis. The surgical outcomes at the 2- and 4-month follow-ups in these patients were investigated and compared with the outcomes in patients without amaurosis using best-corrected visual acuity (BCVA), optical coherence tomography (OCT), and pattern visual evoked potential (PVEP). RESULTS: Both BCVA and the OCT-based macular structure in patients with intraoperative amaurosis showed significant postoperative improvement comparable with that of patients without amaurosis. The presence of intraoperative amaurosis was not associated with either macular hole closure or macular edema regression. PVEP revealed no significant changes in the wave latency or amplitude before and after surgery. CONCLUSION: Intraoperative amaurosis following sub-Tenon's block is commonly seen but does not predict a poor surgical prognosis. When a patient develops amaurosis during surgery, the surgeon should increase patient comfort through verbal communication rather than perform an additional intervention to help relieve the patient's anxiety.

The effectiveness of an interactive audio-tactile map for the process of cognitive mapping and recall among people with visual impairments.

BACKGROUND: People with visual impairments can experience numerous challenges navigating unfamiliar environments. Systems that operate as prenavigation tools can assist such individuals. This mixed-methods study examined the effectiveness of an interactive audio-tactile map tool on the process of cognitive mapping and recall, among people who were blind or had visual impairments. The tool was developed with the involvement of visually impaired individuals who additionally provided further feedback throughout this research. METHODS: A mixed-methods experimental design was employed. Fourteen participants were allocated to either an experimental group who were exposed to an audio-tactile map, or a control group exposed to a verbally annotated tactile map. After five minutes' exposure, multiple-choice questions examined participants' recall of the spatial and navigational content. Subsequent semi-structured interviews were conducted to examine their views surrounding the study and the product. RESULTS: The experimental condition had significantly better overall recall than the control group and higher average scores in all four areas examined by the questions. The interviews suggested that the interactive component offered individuals the freedom to learn the map in several ways and did not restrict them to a sequential and linear approach to learning. CONCLUSION: Assistive technology can reduce challenges faced by people with visual impairments, and the flexible learning approach offered by the audio-tactile map may be of particular value. Future researchers and assistive technology developers may wish to explore this further.

Prevalence and causes of vision loss in sub-Saharan Africa in 2015: magnitude, temporal trends and projections.

BACKGROUND: This study aimed to assess the prevalence and causes of vision loss in sub-Saharan Africa (SSA) in 2015, compared with prior years, and to estimate expected values for 2020. METHODS: A systematic review and meta-analysis assessed the prevalence of blindness (presenting distance visual acuity <3/60 in the better eye), moderate and severe vision impairment (MSVI; presenting distance visual acuity <6/18 but ≥3/60) and mild vision impairment (MVI; presenting distance visual acuity <6/12 and ≥6/18), and also near vision impairment (