Yoked prisms and cerebral visual impairment: Enhancing the experience of ambient vision

BACKGROUND

Perceptual visual impairment leads to impaired functional vision in children with cerebral visual impairment. Yoked prisms have been used in behavioral vision therapy for children with autism (dysfunctional dorsal visual processing pathway) and in neurorehabilitation to treat visual neglect, hemianopia, and abnormal egocentric localization. In particular, they are employed for treating perceptual visual problems.

PURPOSE

To share our experience in implementing yoked prisms and their impact on the rehabilitation of children with cerebral visual impairment-related perceptual vision disorders.

SYNOPSIS

The first child with periventricular leukomalacia exhibits no eagerness to explore her new environment along with poor grasp. With 4-PD base-down prisms, she explores her surroundings and appreciates her lateral supports. Her grasp improved as well. The second child with cerebral visual impairment exhibits difficulty in climbing downstairs with poor obstacle negotiation. This could be due to impaired inferior field awareness or optic ataxia. With 4-PD base-down prisms, the field shift toward the apex helps him to climb downstairs without difficulty with an improved obstacle negotiation. The third child prefers a closer look at the object of interest along with poor hand-eye coordination. We employed 4-PD base-down prisms in her rehabilitation session. She showed good improvement in her hand-eye coordination.

HIGHLIGHTS

Poor hand-eye coordination, difficulty climbing downstairs, optic ataxia, impaired field awareness, and triggering spontaneous exploration in children with perceptual visual problems can be effectively tackled by the simple incorporation of yoked prisms.

VIDEO LINK

https://youtu.be/BW3cwiGDTLY.

Availability of disability specialists for students with vision or hearing impairment in the United Arab Emirates: current status and future needs

PURPOSE

This study aims to identify the disability specialists currently needed for students with vision or hearing impairment in the United Arab Emirates (UAE). It also aims to identify the university-level training courses available for these specialists.

MATERIALS AND METHODS

This study adopted a mixed-methods design. The qualitative strand involved a thematic analysis of semi-structured interviews conducted with 20 employees of 10 UAE organizations providing support services to students with vision or hearing impairment. The quantitative strand determined the number of disability-related degree courses offered at UAE universities from 2018 to 2020.

RESULTS

The interviewees revealed that students with visual impairment most need teachers for the visually impaired, braille trainers, orientation and mobility trainers, and assistive technology specialists, whereas students with hearing impairment most need teachers of the deaf or hard of hearing, speech therapists, and sign language specialists. Regarding disability-related training, 10 UAE universities each offered one disability-related programme between 2018 and 2020. These included nine general programmes for special or inclusive education and one programme for speech pathology.

CONCLUSION

UAE universities are currently unable to train the disability specialists required for students with vision or hearing impairment. An interim option is to offer scholarships to enable Emirati students planning to become disability specialists to gain these specialized qualifications overseas. Current efforts in the UAE to address the needs of people with disabilities should include a development and implementation plan for UAE university programmes to offer specialized courses for people with vision or hearing impairment.

Access to eye care and support services among adults from minority ethnic communities living with visual impairment in the United Kingdom

Background

Despite an increased risk of certain eye conditions which can lead to visual impairment (V.I.), there is evidence of a greater delay to treatment-seeking among adults from minority ethnic communities (MEC). MEC adults may also be underrepresented on V.I. registers, within early intervention services, and among the beneficiaries of national V.I. charities. However, much of this evidence is outdated or anecdotal.

Methods

This secondary analysis of V.I. Lives survey data explored use of eye health and support services and mobility aids among a matched control sample of 77 MEC and 77 adults aged 18 and over from white communities (WC). Participants were matched on age, gender, UK region and urban/rural setting. Additional subgroup analysis was conducted for Asian (n = 46) and black participants (n = 22).

Results

There were no significant group differences in areas such as eye health service use, registration status, contact with charities, and level of practical support received. But MEC participants were significantly more likely than WC participants to have received direct payments from social services to cover their care needs, Χ2 (1, 154) = 8.27, p = 0.004, and to use apps on their mobile for mobility, Χ2 (1, 154) = 5.75, p = 0.017. In contrast, WC participants were significantly more likely to agree that they were getting the level of emotional support to get on with their life, U = 3,638, p = 0.010, to feel confident to ask their friends for support, U = 2,416, p = 0.040, and to have a guide dog for mobility, Χ2 (1, 154) = 3.62, p = 0.057, although the latter did not reach statistical significance. Within the MEC group, Asian participants were significantly more likely than black participants to use a long cane, Χ2 (1, 68) = 7.24, p = 0.007, but they were significantly less likely to agree that they had received the right level of support when they started to experience V.I., U = 236.5, p = 0.040.

Conclusion

The preliminary findings suggests that there is scope to increase support provided by V.I. charities and the V.I. register, although, contrary to existing evidence, there were no statistically significant differences in eye health service use, registration status and use of wider support services. Further research is required to confirm these findings and explore reasons for differences.

Impact of special software training on quality of life among people with visual impairment

Purpose

To evaluate the impact of special software training in computer and smartphone apps as a form of rehabilitation to improve the quality of life of individuals with visual impairment (VI).

Methods

The study utilized a one-group pretest-posttest design. A total of 50 individuals aged 15 years and older with VI participated in the training, which included special software (NVDA) and mobile app training for 60 hours at the Visual Rehabilitation Center. The Low Vision Quality of Life Questionnaire was administered before the start of training and six months after completion. The questionnaire covered the following domains: (1) mobility, distance vision, and lighting; (2) reading and fine work; (3) social well-being; (4) economic impact; (5) attitude toward life; and (6) activities of daily living. Statistical software STATA 14.0 (Texas, USA) was used for data analysis. Paired t-tests and Wilcoxon signed-rank tests were conducted to compare the mean differences before and after training.

Results

Significant improvements were observed in five dimensions, namely mobility, distance vision and lighting, reading and fine work, and attitude toward life, at a highly significant level of 1% probability. The dimensions of social well-being and economic impact showed significant improvement at a 5% level of probability.

Conclusion

Visual impairment, whether congenital or acquired later in life, affects independence in all aspects of life. To the best of our knowledge, this is the first study to investigate the impact of special software training on the quality of life of visually impaired individuals. The authors suggest that this form of rehabilitation enhances accessibility to mainstream living, promotes independence, and ultimately improves quality of life. Participants experienced an improved quality of life through increased access to mainstream resources, enhanced ability to navigate and manage daily activities independently, and reduced reliance on multiple low vision aids or assistance from sighted individuals.

Interventions for perceptual disorders following stroke

BACKGROUND

Perception is the ability to understand information from our senses. It allows us to experience and meaningfully interact with our environment. A stroke may impair perception in up to 70% of stroke survivors, leading to distress, increased dependence on others, and poorer quality of life. Interventions to address perceptual disorders may include assessment and screening, rehabilitation, non-invasive brain stimulation, pharmacological and surgical approaches.

OBJECTIVES

To assess the effectiveness of interventions aimed at perceptual disorders after stroke compared to no intervention or control (placebo, standard care, attention control), on measures of performance in activities of daily living.  SEARCH METHODS: We searched the trials registers of the Cochrane Stroke Group, CENTRAL, MEDLINE, Embase, and three other databases to August 2021. We also searched trials and research registers, reference lists of studies, handsearched journals, and contacted authors.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of adult stroke survivors with perceptual disorders. We defined perception as the specific mental functions of recognising and interpreting sensory stimuli and included hearing, taste, touch, smell, somatosensation, and vision. Our definition of perception excluded visual field deficits, neglect/inattention, and pain.

DATA COLLECTION AND ANALYSIS

One review author assessed titles, with two review authors independently screening abstracts and full-text articles for eligibility. One review author extracted, appraised, and entered data, which were checked by a second author. We assessed risk of bias (ROB) using the ROB-1 tool, and quality of evidence using GRADE.  A stakeholder group, comprising stroke survivors, carers, and healthcare professionals, was involved in this review update.

MAIN RESULTS

We identified 18 eligible RCTs involving 541 participants. The trials addressed touch (three trials, 70 participants), somatosensory (seven trials, 196 participants) and visual perception disorders (seven trials, 225 participants), with one (50 participants) exploring mixed touch-somatosensory disorders. None addressed stroke-related hearing, taste, or smell perception disorders. All but one examined the effectiveness of rehabilitation interventions; the exception evaluated non-invasive brain stimulation. For our main comparison of active intervention versus no treatment or control, one trial reported our primary outcome of performance in activities of daily living (ADL):  Somatosensory disorders: one trial (24 participants) compared an intervention with a control intervention and reported an ADL measure.  Touch perception disorder: no trials measuring ADL compared an intervention with no treatment or with a control intervention.  Visual perception disorders: no trials measuring ADL compared an intervention with no treatment or control.  In addition, six trials reported ADL outcomes in a comparison of active intervention versus active intervention, relating to somatosensation (three trials), touch (one trial) and vision (two trials).   AUTHORS' CONCLUSIONS: Following a detailed, systematic search, we identified limited RCT evidence of the effectiveness of interventions for perceptual disorders following stroke. There is insufficient evidence to support or refute the suggestion that perceptual interventions are effective. More high-quality trials of interventions for perceptual disorders in stroke are needed. They should recruit sufficient participant numbers, include a 'usual care' comparison, and measure longer-term functional outcomes, at time points beyond the initial intervention period. People with impaired perception following a stroke should continue to receive neurorehabilitation according to clinical guidelines.

Influence of COVID-19 Lockdowns on the Usage of a Vision Assistance App Among Global Users With Visual Impairment: Big Data Analytics Study

BACKGROUND

Millions of individuals with visual impairment use vision assistance apps to help with their daily activities. The most widely used vision assistance apps are magnifier apps. It is still largely unknown what the apps are used for. Lack of insight into the visual needs of individuals with visual impairment is a hurdle for the development of more effective assistive technologies.

OBJECTIVE

This study aimed to investigate how needs for visual aids may vary with social activities, by observing the changes in the usage of a smartphone magnifier app when many users take breaks from work.

METHODS

The number of launches of the SuperVision Magnifier app was determined retrospectively from 2018 to 2020 from among active users worldwide. The fluctuation in app usage was examined by comparing weekday vs weekend periods, Christmas and new year vs nonholiday seasons, and COVID-19 lockdowns vs the easing of restriction during the pandemic.

RESULTS

On average, the app was used 262,466 times by 38,237 users each month in 2020 worldwide. There were two major trough points on the timeline of weekly app usage, one aligned with the COVID-19 lockdowns in April 2020 and another aligned with the Christmas and new year week in 2018 and 2019. The app launches declined by 6947 (11% decline; P<.001) during the lockdown and by 5212 (9% decline; P=.001) during the holiday weeks. There was no significant decline during March to May 2019. App usage compensated for seasonal changes was 8.6% less during weekends than during weekdays (P<.001).

CONCLUSIONS

The need for vision assistance technology was slightly lower during breaks and lockdowns, probably because the activities at home were different and less visually demanding. Nevertheless, for the entire user population, the needs for visual aids are still substantial.

Tele-rehabilitation for visually challenged students during COVID-19 pandemic: Lesson learned

PURPOSE

The COVID-19 outbreak poses a global crisis in health care delivery system, including habilitation and rehabilitation services. In this study, we shared our experiences on telerehabilitation services established primarily for students with visual disabilities (SwVD) amidst COVID-19 pandemic and its outputs.

METHODS

Following the lockdown declared on March 23, 2020, the rehabilitative team of a tertiary eye center in north India received information that many visually challenged students (VCS) were stranded in schools for the blind in Delhi, and feeling with anxiety and panic in absence of teachers. Shortly, the room for vision rehabilitation clinic was set-up for telefacilities. The intended services were explained while disseminating the mobile numbers. A semi-structured questionnaire consisting of closed and open-ended was developed to record COVID-19 knowledge and concerns. Inductive content analysis was used to report the qualitative information.

RESULTS

As of June 30, 2020, a total of 492 clients contacted the team, with maximum from Delhi (41.5%), and predominantly males (78.8%). Around 80.3% of callers were VCS with age range of 11 to 30 years. The two most frequently encountered health needs were itching in eyes (36.1%) and headache (29%). Television news was the most used medium among callers to get COVID-19 information. Cough is a less frequently known mode of transmission (28%), similarly handwashing as a less known for prevention (17.2%). Eight concerns were recorded based on qualitative data analysis.

CONCLUSION

Telerehabilitation provides valuable insights and has the potential to address various concerns, uncertainty, anxiety, and fear among VCS during the pandemic.

Rehabilitation of cortically induced visual field loss

PURPOSE OF REVIEW

Homonymous visual field defects are a common sequela of stroke, and are assumed to be permanent within a few weeks of the event. Because consensus about the efficacy of rehabilitation is lacking, visual therapy is rarely prescribed. Here, we review current rehabilitation options and strategies in the translational pipeline that could change these perspectives.

RECENT FINDINGS

The mainstays of available therapy for homonymous visual defects are compensation training and substitution, which allow patients to better use their spared vision. However, early clinical studies suggest that vision can partially recover following intensive training inside the blind field. Research into the relative efficacy of different restorative approaches continues, providing insights into neurophysiologic substrates of recovery and its limitations. This, in turn, has led to new work examining the possible benefits of earlier intervention, advanced training procedures, noninvasive brain stimulation, and pharmacological adjuvants, all of which remain to be vetted through properly powered, randomized, clinical trials.

SUMMARY

Research has uncovered substantial visual plasticity after occipital strokes, suggesting that rehabilitative strategies for this condition should be more aggressive. For maximal benefit, poststroke vision-restorative interventions should begin early, and in parallel with strategies that optimize everyday use of an expanding field of view.

Clinical guidelines for the management of keratoconus patients with gas permeable contact lenses based on expert consensus and available evidence

PURPOSE OF REVIEW

Fitting rigid gas permeable contact lenses (RGP CLs) in keratoconic patients is the most common visual rehabilitation option to improve patients' quality of life, but require long patient and practitioner chair time. The purpose of this review is to provide evidence-based clinical practice guidelines (CPG) in the management of patients with keratoconus with RGP CLs.

RECENT FINDINGS

An extensive literature review from 1990 to 2017 identified 354 potentially relevant publications. Fifty-two articles were reviewed and included in the CPG. An international expert panel of eight contact lens practitioners, with vast experience in keratoconus management reviewed and appraised the CPG following the Appraisal of Guidelines for Research and Evaluation II consortium requirements. The developed CPG clearly outlines a strategy for the successful fitting of RGP CLs in patients with keratoconus. This includes how to calculate parameters of the first diagnostic lens, criteria for assessing good fit and a standardized schedule of wear time and follow-up appointments.

SUMMARY

The current evidence and consensus-based CPG helps guide clinicians in a successful strategy for fitting RGP CLs in patients with keratoconus.

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.

Effects of environmental explanation using three-dimensional tactile maps for orientation and mobility training

We developed a new kit to assemble three-dimensional (3D) tactile maps for orientation and mobility (O&M) training provided to persons with visual impairments. This study evaluated the effects of verbal explanations combined with 3D tactile map kits in improving understanding, recall, and walking along an unfamiliar route in comparison with the effects of only verbal explanation. The 3D tactile maps provided participants having severe visual impairments and little experience with tactile maps with a better understanding and recall of the environmental information concerning the route and landmarks. Participants who used the 3D tactile maps could find specific landmarks set as tasks more accurately and arrive at the destination alone getting lost less frequently. Tactile maps composed of 3D points, lines, and areal parts are useful as a support aid for O&M training because they have high tactile readability and can provide the environmental information that individuals with visual impairment require.

Transfer and retention of oculomotor alignment rehabilitation training

Ocular alignment defects such as strabismus affect around 5% of people and are associated with binocular vision impairments. Current nonsurgical treatments are controversial and have high levels of recidivism. In this study, we developed a rehabilitation method for ocular alignment training and examined the rate of learning, transfer to untrained alignments, and retention over time. Ocular alignment was controlled with a real-time dichoptic feedback paradigm where a static fixation target and white gaze-contingent ring were presented to the dominant eye and a black gaze-contingent ring with no fixation target was presented to the nondominant eye. Observers were required to move their eyes to center the rings on the target, with real-time feedback provided by the size of the rings. Offsetting the ring of the nondominant temporal or nasal visual field required convergent or divergent ocular deviation, respectively, to center the ring on the fixation target. Learning was quantified as the time taken to achieve target deviation of 2° (easy, E) or 4° (hard, H) for convergence (CE, CH) or divergence (DE, DH) over 40 trials. Thirty-two normally sighted observers completed two training sequences separated by one week. Subjects were randomly assigned to a training sequence: CE-CH-DE, CH-CE-DE, DE-DH-CE, or DH-DE-CE. The results showed that training was retained over the course of approximately one week across all conditions. Training on an easy deviation angle transferred to untrained hard angles within convergence or divergence but not between these directions. We conclude that oculomotor alignment can be rapidly trained, retained, and transferred with a feedback-based dichoptic paradigm. Feedback-based oculomotor training may therefore provide a noninvasive method for the rehabilitation of ocular alignment defects.

Artificial Intelligence for Cataract Detection and Management

The rising popularity of artificial intelligence (AI) in ophthalmology is fuelled by the ever-increasing clinical "big data" that can be used for algorithm development. Cataract is one of the leading causes of visual impairment worldwide. However, compared with other major age-related eye diseases, such as diabetic retinopathy, age-related macular degeneration, and glaucoma, AI development in the domain of cataract is still relatively underexplored. In this regard, several previous studies explored algorithms for automated cataract assessment using either slit lamp of color fundus photographs. However, several other study groups proposed or derived new AI-based calculation for pre-cataract surgery intraocular lens power. Along with advancements in digitization of clinical data, data curation for future cataract-related AI developmental work is bound to undergo significant improvements in the foreseeable future. Even though most of these previous studies reported early promising performances, limitations such as lack of robust, high-quality training data, and lack of external validations remain. In the next phase of work, apart from algorithm's performance, it will also be pertinent to evaluate deployment angles, feasibility, efficiency, and cost-effectiveness of these new cataract-related AI systems.

Interventions Addressing Vision, Visual-perceptual Impairments Following Acquired Brain Injury: A Cross-sectional Survey

BACKGROUND.

The existing literature on the effectiveness of interventions targeting vision, visual-perceptual impairments following acquired brain injury (ABI) is scarce and unlinked to occupational performance.

PURPOSE.

To explore current occupational therapy practice in vision-rehabilitation among adults with ABI in Canada, and to determine the evidence-practice gaps.

METHODS.

An online survey was made available through the Canadian Association of Occupational Therapists (CAOT) website, and disseminated to seven public healthcare institutions in Quebec. The survey collected respondent demographic information, and the types and frequency of treatments delivered. Descriptive statistics were conducted to determine interventions' frequency. Participant comments were collected and grouped into recurring themes.

FINDINGS.

Over half (55%) of respondents regularly use evidence-based interventions when addressing visual acuity (VA) and visual field (VF) deficits, but only very few (3%) use it when dealing with oculomotor function and visual stress impairments.

IMPLICATIONS.

Results gave a glimpse of interventions used and suggested the need for further research in vision rehabilitation.

A Multiform, Group-Based Rehabilitation Program for Visually Impaired Young People to Promote Activity and Participation. A Pilot Study

Young people with visual impairment (YPWVI) face several challenges in their everyday lives. However, little is known about interventions that focus on promoting their participation that contributes to health and well-being and is considered the most relevant outcome in rehabilitation. Objectives: This study investigated the clinical outcomes and acceptability of a new one-year, multiform, group-based rehabilitation program for YPWVI. The aim of the pilot program was to support them becoming more independent and to promote their participation. Rehabilitation consisted of group-meetings in an institutional setting, online group meetings, individually tailored one-on-one guidance, individual online discussions and parents’ group meetings. Fifteen young persons with visual impairment were recruited and 14 completed the intervention, six of whom were blind or had severe visual impairment and eight had mild visual loss. Methodology: The study utilized a mixed methods triangulation design. Clinical outcome measures were goal attainment scaling (GAS) and occupational performance (COPM) completed with qualitative interview data. Focus group interviews with participants and parents were used to evaluate the acceptability of the program. Results: GAS-rated personal goals were widely achieved and the scores of both performance and satisfaction scales of COPM improved. Overall, the rehabilitation program proved to be acceptable. Group-based rehabilitation was deemed very important and it enabled peer support. However, two-day periods of inpatient rehabilitation, proved to be too short, whereas five-day periods were considered to disturb schoolwork. Conclusions: Group-based multi-form rehabilitation for YPWVI can have a positive impact on activity and participation of the participants. The program can support independence and the achievement of rehabilitation goals. The group format was applauded for providing social support and company. The program required some structural modifications.

Eye Conditions in Infants and Children: Accommodations for Children With Vision Impairment

The effects of vision impairment and blindness on children can last a lifetime. Most children with vision impairments need a multidisciplinary team of teachers, child development specialists, and social workers. Blindness often is associated with other risk factors, disease processes, and/or disabilities. In the United States, the Social Security Administration defines children as legally blind when best corrected visual acuity is less than 20/200. The US law concerning accommodations for children with impairments is part of the Americans with Disabilities Act of 1990 (ADA), and specifically the Individuals with Disabilities Education Act (IDEA), which covers preschool-age and school-age children. Accommodations for children with vision impairment include low vision aids allowing them to stay in mainstream classes and schools.

Enhancing general spatial skills of young visually impaired people with a programmable distance discrimination training: a case control study

BACKGROUND

The estimation of relative distance is a perceptual task used extensively in everyday life. This important skill suffers from biases that may be more pronounced when estimation is based on haptics. This is especially true for the blind and visually impaired, for which haptic estimation of distances is paramount but not systematically trained. We investigated whether a programmable tactile display, used autonomously, can improve distance discrimination ability in blind and severely visually impaired youngsters between 7 and 22 years-old.

METHODS

Training consisted of four weekly sessions in which participants were asked to haptically find, on the programmable tactile display, the pairs of squares which were separated by the shortest and longest distance in tactile images with multiple squares. A battery of haptic tests with raised-line drawings was administered before and after training, and scores were compared to those of a control group that did only the haptic battery, without doing the distance discrimination training on the tactile display.

RESULTS

Both blind and severely impaired youngsters became more accurate and faster at the task during training. In haptic battery results, blind and severely impaired youngsters who used the programmable display improved in three and two tests, respectively. In contrast, in the control groups, the blind control group improved in only one test, and the severely visually impaired in no tests.

CONCLUSIONS

Distance discrimination skills can be trained equally well in both blind and severely impaired participants. More importantly, autonomous training with the programmable tactile display had generalized effects beyond the trained task. Participants improved not only in the size discrimination test but also in memory span tests. Our study shows that tactile stimulation training that requires minimal human assistance can effectively improve generic spatial skills.

Influence of Attentional Focus Instructions on Motor Performance Among Adolescents With Severe Visual Impairment

Substantial research has demonstrated that an external (vs. internal) attentional focus enhances motor performance among various populations. Interest has recently grown in examining the effects of attentional focus among individuals with visual impairments (VI), and, to date, research results have been conflicting with some studies supporting a potential benefit to an external focus among adults with VI, while a study of children with severe VI was inconclusive regarding this benefit. The present investigation compared the effects of an internal versus an external attentional focus on a discrete throwing task among adolescents with severe VI. We recruited 13 participants with a visual acuity score of less than 6/60 and had them throw a Goalball (25 cm ball with bells often used in competitive sports designed for people with VI) as fast as possible for three familiarization trials, three internal focus trials, and three external focus trials. These participants threw the ball with significantly higher velocity when using an external focus than in other conditions, indicating a benefit from an external focus for this population when performing this discrete task.

The effects of reading mode and braille reading patterns on braille reading speed and comprehension: A study of students with visual impairments in China

The purpose of this study was to examine the effects of reading mode (oral and silent reading) and braille reading patterns (one-handed pattern, mark pattern, parallel pattern, cooperative pattern) on the reading speed and comprehension of students with visual impairments in China. Seventy-three students with visual impairments aged 10-19 years participated in the study; 48 were students with congenital visual impairments and 25 were students with adventitious visual impairments. The participants' braille reading performance was assessed by the Chinese Reading Comprehension Test. Measurement indicators included reading speed (wpm) and reading comprehension. The results indicated that (1) Reading mode had a significant effect on both reading speed and reading comprehension. More specifically, although participants read faster in silent reading than in oral reading, they demonstrated better reading comprehension in oral reading than in silent reading. (2) There was a significant interaction effect between reading mode and braille reading patterns on reading speed. In particular, participants using cooperative and one-handed patterns read faster than other patterns in silent reading. This difference did not exist in the oral reading mode. (3) There was no difference between the measurement indicators of the students with congenital and adventitious visual impairments. Implications and recommendations are given based on the analyses.

[Ophthalmological evaluation in children referred to a low-vision rehabilitation project of a social assistance agency]

INTRODUCTION

A low-vision (LV) rehabilitated child can receive comprehensive education. Objec tive: To study the profile of school children referred for evaluation to a rehabilitation project in a social assistance agency.

PATIENTS AND METHOD

Descriptive cross-sectional study of beneficiaries evaluated between September 2015 and September 2016 in the National Board of School Assistan ce and Scholarships (JUNAEB). The referral diagnosis, monocular visual acuity (VA) with optical correction at far (Feinbloom chart) and close (Zeiss chart) distances were considered. They were classified according to VA and perimetry. Treatment success was considered if VA reaches > 0.4 at far and/or close distances with optical devices.

RESULTS

278 students were assessed. 153 (55%) were men, 121 (43.5%) between the ages of 10 to 14. Bilateral congenital cataract, retinal dystrophies, high myopia, optic atrophy, and congenital nystagmus were the most frequent pathologies. 224 students (80.6%) received optical devices. 85 (37.9%) presented moderate LV and 63 (28.6%) severe LV; 122 (54.5%) presented normal perimetry, 68 (30.4%) tubular Visual Field (VF), 19 (8.5%) sectoral VF defects, and 15 (6.7%) central scotoma. 198 (88.4%) students achieved visual success at a far distance and all achieved visual success at a near distance. 48 (17.2%) students could not be rehabilitated due to a neuro-ophthalmological condition (41.7%), high refractive error (16.6%) or congenital glauco ma (10.4%).Six (2.2%) cases improved VA with a new optical correction.

CONCLUSION

This success demonstrates the need to provide low vision aids to schoolchildren with LV. Our challenge is to maintain this program and to educate ophthalmologist for timely referral.

Interventions for visual field defects in people with stroke

BACKGROUND

Visual field defects are estimated to affect 20% to 57% of people who have had a stroke. Visual field defects can affect functional ability in activities of daily living (commonly affecting mobility, reading and driving), quality of life, ability to participate in rehabilitation, and depression and anxiety following stroke. There are many interventions for visual field defects, which are proposed to work by restoring the visual field (restitution); compensating for the visual field defect by changing behaviour or activity (compensation); substituting for the visual field defect by using a device or extraneous modification (substitution); or ensuring appropriate diagnosis, referral and treatment prescription through standardised assessment or screening, or both.

OBJECTIVES

To determine the effects of interventions for people with visual field defects after stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register, the Cochrane Eyes and Vision Group Trials Register, CENTRAL, MEDLINE, Embase, CINAHL, AMED, PsycINFO, and PDQT Databse, and clinical trials databases, including ClinicalTrials.gov and WHO Clinical Trials Registry, to May 2018. We also searched reference lists and trials registers, handsearched journals and conference proceedings, and contacted experts.

SELECTION CRITERIA

Randomised trials in adults after stroke, where the intervention was specifically targeted at improving the visual field defect or improving the ability of the participant to cope with the visual field loss. The primary outcome was functional ability in activities of daily living and secondary outcomes included functional ability in extended activities of daily living, reading ability, visual field measures, balance, falls, depression and anxiety, discharge destination or residence after stroke, quality of life and social isolation, visual scanning, adverse events, and death.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened abstracts, extracted data and appraised trials. We undertook an assessment of methodological quality for allocation concealment, blinding of outcome assessors, method of dealing with missing data, and other potential sources of bias. We assessed the quality of evidence for each outcome using the GRADE approach.

MAIN RESULTS

Twenty studies (732 randomised participants, with data for 547 participants with stroke) met the inclusion criteria for this review. However, only 10 of these studies compared the effect of an intervention with a placebo, control, or no treatment group, and eight had data which could be included in meta-analyses. Only two of these eight studies presented data relating to our primary outcome of functional abilities in activities of daily living. One study reported evidence relating to adverse events.Three studies (88 participants) compared a restitutive intervention with a control, but data were only available for one study (19 participants). There was very low-quality evidence that visual restitution therapy had no effect on visual field outcomes, and a statistically significant effect on quality of life, but limitations with these data mean that there is insufficient evidence to draw any conclusions about the effectiveness of restitutive interventions as compared to control.Four studies (193 participants) compared the effect of scanning (compensatory) training with a control or placebo intervention. There was low-quality evidence that scanning training was more beneficial than control or placebo on quality of life, measured using the Visual Function Questionnaire (VFQ-25) (two studies, 96 participants, mean difference (MD) 9.36, 95% confidence interval (CI) 3.10 to 15.62). However, there was low or very-low quality evidence of no effect on measures of visual field, extended activities of daily living, reading, and scanning ability. There was low-quality evidence of no significant increase in adverse events in people doing scanning training, as compared to no treatment.Three studies (166 participants) compared a substitutive intervention (a type of prism) with a control. There was low or very-low quality evidence that prisms did not have an effect on measures of activities of daily living, extended activities of daily living, reading, falls, or quality of life, and very low-quality evidence that they may have an effect on scanning ability (one study, 39 participants, MD 9.80, 95% CI 1.91 to 17.69). There was low-quality evidence of an increased odds of an adverse event (primarily headache) in people wearing prisms, as compared to no treatment.One study (39 participants) compared the effect of assessment by an orthoptist to standard care (no assessment) and found very low-quality evidence that there was no effect on measures of activities of daily living.Due to the quality and quantity of evidence, we remain uncertain about the benefits of assessment interventions.

AUTHORS' CONCLUSIONS

There is a lack of evidence relating to the effect of interventions on our primary outcome of functional ability in activities of daily living. There is limited low-quality evidence that compensatory scanning training may be more beneficial than placebo or control at improving quality of life, but not other outcomes. There is insufficient evidence to reach any generalised conclusions about the effect of restitutive interventions or substitutive interventions (prisms) as compared to placebo, control, or no treatment. There is low-quality evidence that prisms may cause minor adverse events.

Vision screening services in special needs schools in Western Saudi Arabia

Objectives:

To evaluate the current status of vision screening services in special educational needs (SEN) schools in the western region of Saudi Arabia.

Methods:

This was a cross-sectional study that involved distribution of a questionnaire to all 30 SENs schools in the western region of Saudi Arabia between April and May 2018.

Results:

Twenty-three schools responded to the questionnaire (77% response rate). The number of pupils represented in the surveyed schools was 1831. On average, 10.8% of pupils were reported to wear eyeglasses. Approximately 60.9% of schools reported that vision screening was not offered at their schools. The percentage of students who used optical, non-optical, or high-technology low-vision aids was <2.7%. Most participants (78.3%) reported that no one in their schools had received some form of training to work with and support students with visual impairments.

Conclusion:

In the western province of Saudi Arabia, the vision care status of individuals with intellectual disabilities (ID) in SEN schools is poor. To better serve this underprivileged group, the necessity of implementing vision screening programs on a larger scale should be considered.

Unifying obstacle detection, recognition, and fusion based on millimeter wave radar and RGB-depth sensors for the visually impaired

It is very difficult for visually impaired people to perceive and avoid obstacles at a distance. To address this problem, the unified framework of multiple target detection, recognition, and fusion is proposed based on the sensor fusion system comprising a low-power millimeter wave (MMW) radar and an RGB-Depth (RGB-D) sensor. In this paper, the Mask R-CNN and the single shot multibox detector network are utilized to detect and recognize the objects from color images. The obstacles' depth information is obtained from the depth images using the MeanShift algorithm. The position and velocity information on the multiple target is detected by the MMW radar based on the principle of a frequency modulated continuous wave. The data fusion based on the particle filter obtains more accurate state estimation and richer information by fusing the detection results from the color images, depth images, and radar data compared with using only one sensor. The experimental results show that the data fusion enriches the detection results. Meanwhile, the effective detection range is expanded compared to using only the RGB-D sensor. Moreover, the data fusion results keep high accuracy and stability under diverse range and illumination conditions. As a wearable system, the sensor fusion system has the characteristics of versatility, portability, and cost-effectiveness.

System for Face Recognition under Different Facial Expressions Using a New Associative Hybrid Model Amαβ-KNN for People with Visual Impairment or Prosopagnosia

Face recognition is a natural skill that a child performs from the first days of life; unfortunately, there are people with visual or neurological problems that prevent the individual from performing the process visually. This work describes a system that integrates Artificial Intelligence which learns the face of the people with whom the user interacts daily. During the study we propose a new hybrid model of Alpha-Beta Associative memories (Amαβ) with Correlation Matrix (CM) and K-Nearest Neighbors (KNN), where the Amαβ-CMKNN was trained with characteristic biometric vectors generated from images of faces from people who present different facial expressions such as happiness, surprise, anger and sadness. To test the performance of the hybrid model, two experiments that differ in the selection of parameters that characterize the face are conducted. The performance of the proposed model was tested in the databases CK+, CAS-PEAL-R1 and Face-MECS (own), which test the Amαβ-CMKNN with faces of subjects of both sexes, different races, facial expressions, poses and environmental conditions. The hybrid model was able to remember 100% of all the faces learned during their training, while in the test in which faces are presented that have variations with respect to those learned the results range from 95.05% in controlled environments and 86.48% in real environments using the proposed integrated system.

Accessible mathematics videos for non-disabled students in primary education

Our work applies Universal Design criteria for producing and using Mathematics videos for primary education students, at a time when many countries are shifting towards inclusive education policies. We have focused on how the accessibility criteria used for students with visual impairments might affect non-disabled students. For this, we reviewed applicable Universal Design principles as well as best practices in multimedia learning. We took into account the roles, procedures, tools and standards involved in the multimedia lifecycle. We then undertook an experiment consisting of producing two videos about prime numbers with the same pedagogical contents; one video was accessible for students with visual impairments and the other one was not accessible to them. We conducted a trial in real world school settings with 228 non-disabled children, who were randomly assigned a version, either accessible or not accessible, and were then asked to take a test to measure objective aspects of their learning concerning retention and transfer as well as several subjective aspects, including the attractiveness of the videos. Results indicate that there were no significant differences in the scores obtained by students using either video, although the group who watched the accessible video obtained higher score medians in the retention questions. Moreover, students found the accessible video significantly more attractive (p = 0.042). Our study provides recommendations for different stakeholders and stages within the process of producing multimedia mathematics materials that are accessible to primary students with visual impairments, as well as evidence demonstrating that everybody can benefit from the recommendations for developing good quality, accessible multimedia material.

Psychometric properties of a new intake questionnaire for visually impaired young adults: The Participation and Activity Inventory for Young Adults (PAI-YA)

BACKGROUND

To be able to identify and monitor personal needs and goals of visually impaired young adults before and during rehabilitation trajectories, the Participation and Activity for Young Adults (PAI-YA) was developed involving young adults (18-25 years) and professionals as stakeholders. The psychometric properties of this new patient-reported outcome measure were investigated in order to develop an improved version.

METHODS

Young adults registered at two low vision rehabilitation centers in the Netherlands were invited to complete the 141-item PAI-YA (n = 186) in a test-retest design. To select the best items for the PAI-YA, response frequencies were assessed and a graded response model (GRM) was fitted. Item reduction was informed by response frequencies, insufficient item information, and participants' comments. Fit indices, item and person (theta) parameters were computed, after which known-group validity, concurrent validity, test-retest reliability and feasibility were studied.

RESULTS

Response frequencies, violation of assumptions and item information informed the elimination of 81 items, resulting in a unidimensional PAI-YA showing satisfactory fit to the GRM. Known-group validity showed significant differences for visual impairment, financial situation, sex, educational situation and employment situation. Concurrent validity with (scales of) other questionnaires showed moderate to strong expected correlations. Test-retest reliability was satisfactory for all items (kappa 0.47-0.87), as was agreement (63.1-92.0%). Four items and one response option were added to increase feasibility.

CONCLUSIONS

This study contributes to the development and assessment of psychometric properties of the PAI-YA, which resulted in an improved 64-item version. Evidence was provided for construct validity, known-group validity, concurrent validity and test-retest reliability. These results are an important step in the development of a feasible instrument to investigate and monitor rehabilitation needs of visually impaired young adults, to structure the intake procedure at low vision rehabilitation services and to evaluate the effectiveness of rehabilitation.

Fonts Designed for Macular Degeneration: Impact on Reading

Purpose

People with macular degeneration (MD) experience difficulties in reading due to central-field loss. Two new fonts, Eido and Maxular Rx, have been designed specifically for individuals with MD. We have compared reading performance of these new fonts with three mainstream fonts (Times-Roman, Courier, and Helvetica).

Methods

Subjects with MD (n = 19) and normally sighted subjects (n = 40) were tested with digital versions of the MNREAD test using the five fonts. Maximum reading speed (MRS), critical print size (CPS), and reading acuity (RA) were estimated to characterize reading performance. Physical properties of the fonts were quantified by interletter spacing and perimetric complexity.

Results

Reading with MD showed font differences in MRS, CPS, and RA. Compared with Helvetica and Times, Maxular Rx permitted both smaller CPS and RA, and Eido permitted smaller RA. However, the two new fonts presented no advantage over Courier. Spacing, but not Complexity, was a significant predictor of reading performance for subjects with MD.

Conclusions

The two fonts, designed specifically for MD, permit smaller print to be read, but provide no advantage over Courier.

LIDAR Assist Spatial Sensing for the Visually Impaired and Performance Analysis

Echolocation enables people with impaired or no vision to comprehend the surrounding spatial information through the reflected sound. However, this technique often requires substantial training, and the accuracy of echolocation is subject to various conditions. Furthermore, the individuals who practice this sensing method must simultaneously generate the sound and process the received audio information. This paper proposes and evaluates a proof-of-concept light detection and ranging (LIDAR) assist spatial sensing (LASS) system, which intends to overcome these restrictions by obtaining the spatial information of the user's surroundings through a LIDAR sensor and translating the spatial information into the stereo sound of various pitches. The stereo sound of relative pitch represents the information regarding objects' angular orientation and horizontal distance, respectively, thus granting visually impaired users an enhanced spatial perception of his or her surrounding areas and potential obstacles. This paper is divided into two phases: Phase I is to engineer the hardware and software of the LASS system and Phase II focuses on the system efficacy study. The study, approved by the Penn State Institutional Review Board, included 18 student volunteers, who were recruited through the Penn State Department of Psychology Subject Pool. This paper demonstrates that the blindfolded individuals equipped with the LASS system are able to quantitatively identify the surrounding obstacles, differentiate their relative distance, and distinguish the angular location of multiple objects with minimal training.

Diagnostic work-up and rehabilitation of cerebral visual impairment in infancy: A case of epileptic perinatal encephalopathy due to KCNQ2-related channelopathy

BACKGROUND

There is evidence that channelopathies are the cause of many different neurological diseases. The epileptic perinatal encephalopathy due to mutation in the KCNQ2 gene is a rare disease involving severe tetraparesis and cerebral visual impairment. Diseases of this kind are associated with severe disability that involves multiple systems and requires accurate genetic diagnosis and early multidisciplinary care once clinical stability is reached.

CASE REPORT

We describe a case of a baby girl with KCNQ2 encephalopathy who came to our observation for rehabilitation at age 2 years and 6 months.

CLINICAL REHABILITATION IMPACT

We stress the importance of a correct clinical, pharmacological and visual diagnosis. Correct diagnosis made it possible to involve the baby girl and her care-giver in an early process of visual rehabilitation lasting 6 months, the effects of which proved to persist at follow-up after more than a year, making it possible to start a useful inter-professional rehabilitation plan.

Implantable miniature telescope (IMT) for vision loss due to end-stage age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) causes progressive and irreversible damage to the retina, resulting in loss of central vision. AMD is the third leading cause of irreversible visual impairment worldwide and the leading cause of blindness in industrialized countries. Since AMD is more common in older individuals, the number of affected individuals will increase significantly as the population ages. The implantable miniature telescope (IMT) is an ophthalmic device developed to improve vision in individuals who have lost vision due to AMD. Once implanted, the IMT is used to enlarge objects in the central visual field and focus them onto healthy areas of the retina not affected by AMD, allowing individuals to recognize objects that they otherwise could not see. It is unclear whether and how much the IMT can improve vision in individuals with end-stage AMD.

OBJECTIVES

To assess the effectiveness and safety of the IMT in improving visual acuity and quality of life in people with late or advanced AMD.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 11); Ovid MEDLINE; Embase.com; PubMed; LILACS; AMED; Web of Science Conference Proceedings Citation Index-Science; OpenSIGLE; the metaRegister of Controlled Trials (mRCT) (last searched 27 June 2014); ClinicalTrials.gov; the ICTRP and the US Food and Drug Administration (FDA) Medical Devices database. The date of the search was 2 November 2017, with the exception of mRCT which is no longer in service.

SELECTION CRITERIA

We planned to include randomized controlled trials (RCTs) and quasi-randomized trials that compared the IMT versus no IMT.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed all studies for inclusion, using standard methodological procedures expected by Cochrane.

MAIN RESULTS

Our search yielded 1042 unique records. We removed irrelevant studies after screening titles and abstracts, and evaluated five full-text reports from four studies; three were non-randomized studies. There was one ongoing RCT that compared the OriLens intraocular telescope with standard low vision training in eyes with end-stage AMD. Results for this study are expected in 2020.

AUTHORS' CONCLUSIONS

We found no RCT or quasi-RCT and can draw no conclusion about the effectiveness and safety of the IMT in improving visual acuity in individuals with late or advanced AMD. Since the IMT is typically implanted monocularly based upon which eye has better best-corrected distance visual acuity, randomization between eyes within an individual may not be acceptable. Studies are needed that compare outcomes between individuals randomized to the device versus individuals not implanted, at least during study follow-up, who serve as controls.

Assessment of neuro-optometric rehabilitation using the Developmental Eye Movement (DEM) test in adults with acquired brain injury

PURPOSE

This pilot study sought to determine the efficacy of using the Developmental Eye Movement (DEM) test in the adult, acquired brain injury (ABI) population to quantify clinically the effects of controlled, laboratory-performed, oculomotor-based vision therapy/vision rehabilitation.

METHODS

Nine adult subjects with mild traumatic brain injury (mTBI) and five with stroke were assessed before and after an eight-week, computer-based, versional oculomotor (fixation, saccades, pursuit, and simulated reading) training program (9.6h total). The protocol incorporated a cross-over, interventional design with and without the addition of auditory feedback regarding two-dimensional eye position. The clinical outcome measure was the Developmental Eye Movement (DEM) test score (ratio, errors) taken before, midway, and immediately following training.

RESULTS

For the DEM ratio parameter, improvements were found in 80-89% of the subjects. For the DEM error parameter, improvements were found in 100% of the subjects. Incorporation of the auditory feedback component revealed a trend toward enhanced performance. The findings were similar for both DEM parameters, as well as for incorporation of the auditory feedback, in both diagnostic groups.

DISCUSSION

The results of the present study demonstrated considerable improvements in the DEM test scores following the oculomotor-based training, thus reflecting more time-optimal and accurate saccadic tracking after the training. The DEM test should be considered as another clinical test of global saccadic tracking performance in the ABI population.

Vision screening for correctable visual acuity deficits in school-age children and adolescents

BACKGROUND

Although the benefits of vision screening seem intuitive, the value of such programmes in junior and senior schools has been questioned. In addition there exists a lack of clarity regarding the optimum age for screening and frequency at which to carry out screening.

OBJECTIVES

To evaluate the effectiveness of vision screening programmes carried out in schools to reduce the prevalence of correctable visual acuity deficits due to refractive error in school-age children.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 4); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the ICTRP. The date of the search was 3 May 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), including cluster-randomised trials, that compared vision screening with no vision screening, or compared interventions to improve uptake of spectacles or efficiency of vision screening.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results and extracted data. Our pre-specified primary outcome was uncorrected, or suboptimally corrected, visual acuity deficit due to refractive error six months after screening. Pre-specified secondary outcomes included visual acuity deficit due to refractive error more than six months after screening, visual acuity deficit due to causes other than refractive error, spectacle wearing, quality of life, costs, and adverse effects. We graded the certainty of the evidence using GRADE.

MAIN RESULTS

We identified seven relevant studies. Five of these studies were conducted in China with one study in India and one in Tanzania. A total of 9858 children aged between 10 and 18 years were randomised in these studies, 8240 of whom (84%) were followed up between one and eight months after screening. Overall we judged the studies to be at low risk of bias. None of these studies compared vision screening for correctable visual acuity deficits with not screening.Two studies compared vision screening with the provision of free spectacles versus vision screening with no provision of free spectacles (prescription only). These studies provide high-certainty evidence that vision screening with provision of free spectacles results in a higher proportion of children wearing spectacles than if vision screening is accompanied by provision of a prescription only (risk ratio (RR) 1.60, 95% confidence interval (CI) 1.34 to 1.90; 1092 participants). The studies suggest that if approximately 250 per 1000 children given vision screening plus prescription only are wearing spectacles at follow-up (three to six months) then 400 per 1000 (335 to 475) children would be wearing spectacles after vision screening and provision of free spectacles. Low-certainty evidence suggested better educational attainment in children in the free spectacles group (adjusted difference 0.11 in standardised mathematics score, 95% CI 0.01 to 0.21, 1 study, 2289 participants). Costs were reported in one study in Tanzania in 2008 and indicated a relatively low cost of screening and spectacle provision (low-certainty evidence). There was no evidence of any important effect of provision of free spectacles on uncorrected visual acuity (mean difference -0.02 logMAR (95% CI adjusted for clustering -0.04 to 0.01) between the groups at follow-up (moderate-certainty evidence). Other pre-specified outcomes of this review were not reported.Two studies explored the effect of an educational intervention in addition to vision screening on spectacle wear. There was moderate-certainty evidence of little apparent effect of the education interventions investigated in these studies in addition to vision screening, compared to vision screening alone for spectacle wearing (RR 1.11, 95% CI 0.95 to 1.31, 1 study, 3177 participants) or related outcome spectacle purchase (odds ratio (OR) 0.84, 95% CI 0.55 to 1.31, 1 study, 4448 participants). Other pre-specified outcomes of this review were not reported.Three studies compared vision screening with ready-made spectacles versus vision screening with custom-made spectacles. These studies provide moderate-certainty evidence of no clinically meaningful differences between the two types of spectacles. In one study, mean logMAR acuity in better and worse eye was similar between groups: mean difference (MD) better eye 0.03 logMAR, 95% CI 0.01 to 0.05; 414 participants; MD worse eye 0.06 logMAR, 95% CI 0.04 to 0.08; 414 participants). There was high-certainty evidence of no important difference in spectacle wearing (RR 0.98, 95% CI 0.91 to 1.05; 1203 participants) between the two groups and moderate-certainty evidence of no important difference in quality of life between the two groups (the mean quality-of-life score measured using the National Eye Institute Refractive Error Quality of Life scale 42 was 1.42 better (1.04 worse to 3.90 better) in children with ready-made spectacles (1 study of 188 participants). Although none of the studies reported on costs directly, ready-made spectacles are cheaper and may represent considerable cost-savings for vision screening programmes in lower income settings. There was low-certainty evidence of no important difference in adverse effects between the two groups. Adverse effects were reported in one study and were similar between groups. These included blurred vision, distorted vision, headache, disorientation, dizziness, eyestrain and nausea.

AUTHORS' CONCLUSIONS

Vision screening plus provision of free spectacles improves the number of children who have and wear the spectacles they need compared with providing a prescription only. This may lead to better educational outcomes. Health education interventions, as currently devised and tested, do not appear to improve spectacle wearing in children. In lower-income settings, ready-made spectacles may provide a useful alternative to expensive custom-made spectacles.

3-D Object Recognition of a Robotic Navigation Aid for the Visually Impaired

This paper presents a 3-D object recognition method and its implementation on a robotic navigation aid to allow real-time detection of indoor structural objects for the navigation of a blind person. The method segments a point cloud into numerous planar patches and extracts their inter-plane relationships (IPRs).Based on the existing IPRs of the object models, the method defines six high level features (HLFs) and determines the HLFs for each patch. A Gaussian-mixture-model-based plane classifier is then devised to classify each planar patch into one belonging to a particular object model. Finally, a recursive plane clustering procedure is used to cluster the classified planes into the model objects. As the proposed method uses geometric context to detect an object, it is robust to the object's visual appearance change. As a result, it is ideal for detecting structural objects (e.g., stairways, doorways, and so on). In addition, it has high scalability and parallelism. The method is also capable of detecting some indoor non-structural objects. Experimental results demonstrate that the proposed method has a high success rate in object recognition.

Efficacy of vision therapy in children with learning disability and associated binocular vision anomalies

PURPOSE

To report the frequency of binocular vision (BV) anomalies in children with specific learning disorders (SLD) and to assess the efficacy of vision therapy (VT) in children with a non-strabismic binocular vision anomaly (NSBVA).

METHODS

The study was carried out at a centre for learning disability (LD). Comprehensive eye examination and binocular vision assessment was carried out for 94 children (mean (SD) age: 15 (2.2) years) diagnosed with specific learning disorder. BV assessment was done for children with best corrected visual acuity of ≥6/9 - N6, cooperative for examination and free from any ocular pathology. For children with a diagnosis of NSBVA (n=46), 24 children were randomized to VT and no intervention was provided to the other 22 children who served as experimental controls. At the end of 10 sessions of vision therapy, BV assessment was performed for both the intervention and non-intervention groups.

RESULTS

Binocular vision anomalies were found in 59 children (62.8%) among which 22% (n=13) had strabismic binocular vision anomalies (SBVA) and 78% (n=46) had a NSBVA. Accommodative infacility (AIF) was the commonest of the NSBVA and found in 67%, followed by convergence insufficiency (CI) in 25%. Post-vision therapy, the intervention group showed significant improvement in all the BV parameters (Wilcoxon signed rank test, p<0.05) except negative fusional vergence.

CONCLUSION

Children with specific learning disorders have a high frequency of binocular vision disorders and vision therapy plays a significant role in improving the BV parameters. Children with SLD should be screened for BV anomalies as it could potentially be an added hindrance to the reading difficulty in this special population.

Neuro-ophthalmologic disorders following concussion

Visual symptoms, such as photophobia and blurred vision, are common in patients with concussion. Such symptoms may be accompanied by abnormalities of specific eye movements, such as saccades and convergence, or accommodation deficits. The high frequency of visual involvement in concussion is not surprising, since more than half of the brain's pathways are dedicated to vision and eye movement control. These areas include many that are most vulnerable to head trauma, including the frontal and temporal lobes. Vision and eye movement testing is important at the bedside and on the sidelines of athletic events, where brief performance measures that require eye movements, such as rapid number naming, are reliable and sensitive measures for concussion detection. Tests of vision and eye movements are also being explored clinically to identify and monitor patients with symptoms of both sport- and nonsport-related concussion. Evaluation of vision and eye movements can assist in making important decisions after concussion, including the prognosis for symptom recovery, and to direct further visual rehabilitation as necessary.

Vision retention in early versus delayed glaucoma surgical intervention in patients with Boston Keratoprosthesis type 1

IMPORTANCE

The loss of vision following Boston Keratoprosthesis (BKPro) surgery due to glaucoma occurs at a high frequency as diagnosis and management of glaucoma after this procedure pose challenges.

OBJECTIVE

To compare visual outcomes in patients undergoing Boston Keratoprosthesis surgery with and without prior or concurrent glaucoma surgery.

DESIGN, SETTING, AND PARTICIPANTS

This is a retrospective, observational cohort study of patients who underwent Boston Type I Keratoprosthesis surgery. 19 eyes of 18 patients who had undergone BKPro and met the inclusion criteria were identified. Twelve eyes received BKPro with prior or concurrent glaucoma surgery (Group 1), and seven eyes were identified undergoing BKPro surgery without prior or concurrent glaucoma surgery (Group 2).

MAIN OUTCOMES AND MEASURES

Main outcome included best corrected visual acuity at each follow up.

RESULTS

In Group 1, mean best corrected visual acuity (BCVA) within a year of BKPro surgery was 20/100 (range 20/40 to Count Fingers (CF); n = 12) and mean BCVA at 1 year from BKPro surgery was 20/115 (range 20/30 to CF; n = 12). 7 out of 12 patients retained or had improved BCVA at 1 year follow up after BKPro implantation, and 5 out of 12 patients had mild BCVA worsening. In Group 2, the mean BCVA within a year of BKPro surgery was 20/140 (ranging from 20/25 to hand motion vision (HM); n = 7) and mean BCVA at 1 year from BKPro surgery was Count Fingers (range 20/60 to Light Perception (LP); n = 6). 4 out of 6 patients lost significant vision at one year after BKPro.

CONCLUSIONS AND RELEVANCE

BKPro patients with early glaucoma surgical intervention retained vision significantly better compared to patients with late or no intervention. Our preliminary findings support the recommendation for concurrent or pre-emptive glaucoma surgical intervention in patients undergoing BKPro implantation.

Small-Aperture Intraocular Lens Implantation in a Patient With an Irregular Cornea

PURPOSE

To report a small-aperture intraocular lens (IOL) implantation after corneal trauma.

METHODS

Case report.

RESULTS

A 17-year-old boy with corneal scars, iris defect, and aphakia after perforating trauma in the right eye was scheduled for small-aperture IOL (IC-8; AcuFocus, Irvine, CA) implantation under general anesthesia. No intraoperative complications were observed. Six months after surgery, the uncorrected distance and near visual acuity increased significantly. Furthermore, reduced photopic phenomena were reported.

CONCLUSIONS

The small-aperture IOL is a new and promising option to treat patients suffering from the effects of corneal irregularities. [J Refract Surg. 2016;32(10):706-708.].

Vision science and adaptive optics, the state of the field

Adaptive optics is a relatively new field, yet it is spreading rapidly and allows new questions to be asked about how the visual system is organized. The editors of this feature issue have posed a series of question to scientists involved in using adaptive optics in vision science. The questions are focused on three main areas. In the first we investigate the use of adaptive optics for psychophysical measurements of visual system function and for improving the optics of the eye. In the second, we look at the applications and impact of adaptive optics on retinal imaging and its promise for basic and applied research. In the third, we explore how adaptive optics is being used to improve our understanding of the neurophysiology of the visual system.

The Prevalence and Demographic Associations of Presenting Near-Vision Impairment Among Adults Living in the United States

PURPOSE

To estimate prevalence of presenting near-vision impairment (PNVI) among people aged ≥50 years in the United States (US) and examine associations with sociodemographic characteristics.

DESIGN

Cross-sectional study.

METHODS

A total of 11 016 of 12 781 (88.5%) US adults aged ≥50 years participated in the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2008 with recorded near visual acuity. PNVI was defined as presenting near vision worse than 20/40; functional near-vision impairment (FNVI) was defined as at least "moderate difficulty" with either reading newsprint or near work. Prevalence of PNVI and FNVI were estimated accounting for National Health and Nutrition Examination Survey multistage probability sampling design. Multivariable regression models were used to determine sociodemographic characteristics associated with PNVI.

RESULTS

A total of 13.6% of participants had PNVI, with 25.9% reporting concurrent FNVI. Higher odds of PNVI was associated with nonwhite race, older age, male sex, less than high school education, lack of private health insurance, income less than poverty level, lacking/not using near-vision correction at time of examination, and impaired distance vision. Although the majority of participants with PNVI (82.9%) had normal distance vision or uncorrected refractive error, less than half (46.1%) used near-vision correction. Not using near correction was associated with nonwhite race, younger age, male sex, and lack of access to health care.

CONCLUSIONS

Approximately 1 in 8 Americans aged ≥50 years have PNVI, with 1 in 4 reporting concurrent FNVI. Demographic factors shown to be important in access to eye care likely influence PNVI and utilization of near-vision correction in the US. As the majority of PNVI is likely correctable with spectacles, allocation of resources to provide corrective lenses to those in need likely has great public health implications.

Rapid Vision Correction by Special Operations Forces

BACKGROUND

This report describes a rapid method of vision correction used by Special Operations Medics in multiple operational engagements.

METHODS

Between 2011 and 2015, Special Operations Medics used an algorithm- driven refraction technique. A standard block of instruction was provided to the medics, along with a packaged kit. The technique was used in multiple operational engagements with host nation military and civilians. Data collected for program evaluation were later analyzed to assess the utility of the technique.

RESULTS

Glasses were distributed to 230 patients with complaints of either decreased distance or near (reading). Most patients (84%) with distance complaints achieved corrected binocular vision of 20/40 or better, and 97% of patients with near-vision complaints achieved corrected near-binocular vision of 20/40 or better. There was no statistically significant difference between the percentages of patients achieving 20/40 when medics used the technique under direct supervision versus independent use.

CONCLUSION

A basic refraction technique using a designed kit allows for meaningful improvement in distance and/or near vision at austere locations. Special Operations Medics can leverage this approach after specific training with minimal time commitment. It can serve as a rapid, effective intervention with multiple applications in diverse operational environments.

Surgical Correction of Presbyopic Ametropia With Non-refractive Transparent Corneal Inlay and an Implantable Collamer Lens

PURPOSE

To report the clinical outcomes of two patients implanted with the Raindrop Near Vision Inlay (ReVision Optics, Inc., Lake Forest, CA) to correct for presbyopia and the Visian implantable collamer lens (ICL) (STAAR Surgical, Monrovia, CA) to correct refractive error.

METHODS

Case report.

RESULTS

Two patients with presbyopic ametropia complained of blurred vision for distance and near. Both patients received a corneal inlay in the non-dominant eye followed by the Raindrop Inlay the following day. The first patient had an inlay decentration associated with corneal edema and excessive intraocular collamer lens (ICL) vaulting. After ICL exchange and inlay recentration, the ICL stayed properly placed in the ciliary sulcus, and the Raindrop Inlay was well centered. The second patient underwent an uneventful procedure and experienced no complications. At the last visit, both patients were able to see 1.0 (20/20 Snellen) uncorrected visual acuity for distance and near and were satisfied with their vision.

CONCLUSIONS

These two cases suggest that the combination of an ICL with a Raindrop Inlay results in good visual outcomes and patient satisfaction. When combining Raindrop Inlay surgery with an intraocular procedure such as Visian ICL implantation, careful lens selection and sizing are required because there may be an increased risk for inlay decentration associated with corneal edema. [J Refract Surg. 2016;32(12):852-854.].

Long-term Repeatability and Reproducibility of Phosphene Characteristics in Chronically Implanted Argus II Retinal Prosthesis Subjects

PURPOSE

Previously published literatures of acute studies on few subjects have shown contradictory evidence on the reproducibility and characteristics of the elicited phosphenes, despite using the same stimulating parameters with epiretinal electrode arrays. In this study, we set out to investigate the long-term repeatilibity and reproducibility of phosphenes in subjects chronically implanted with the Argus II retinal prosthesis (Second Sight Medical Products, Inc., Sylmar, CA, USA).

DESIGN

Retrospective interventional case series and reliability study.

METHODS

Six Argus II subjects of >5 years implantation from a single site participated. The 4-electrode cluster ("quad") closest to fovea was stimulated in each subject with a fixed biphasic current. Perceived phosphenes were depicted relative to subjective visual field center. The stimulus was applied at reducing time intervals from 20 minutes to 1 second. Two sets of stimulations were performed on the same day and 2 further sets repeated on a separate visit >1 week apart.

RESULTS

Each subject depicted phosphenes of consistent shapes and sizes, and reported seeing the same colors with the fixed stimulating parameters, irrespective of the interstimuli intervals. However, there is a wide intersubject variation in the phosphene characteristics. Four subjects drew phosphenes in the same visual field quadrant, as predicted by the quad-fovea location. Two subjects depicted phosphenes in the same hemifield as the expected locations.

CONCLUSION

Phosphenes for each subject were consistently reproducible in all our chronically implanted subjects. This has important implications in the development of long-term pixelated prosthetic vision for future devices.

Effect of chromatic filters on visual performance in individuals with mild traumatic brain injury (mTBI): A pilot study

PURPOSE

Spectral filters have been used clinically in patients with mild traumatic brain injury (mTBI). However, they have not been formally assessed using objective techniques in this population. Thus, the aim of the present pilot study was to determine the effect of spectral filters on reading performance and visuo-cortical responsivity in adults with mTBI.

METHODS

12 adults with mTBI/concussion were tested. All reported photosensitivity and reading problems. They were compared to 12 visually-normal, asymptomatic adults. There were several test conditions: three luminance-matched control filters (gray neutral density, blue, and red), the patient-selected 'precision tint lens' that provided the most comfort and clarity of text using the Intuitive Colorimeter System, and baseline without any filters. The Visagraph was used to assess reading eye movements and reading speed objectively with each filter. In addition, both the amplitude and latency of the visual-evoked potential (VEP) were assessed with the same filters.

RESULTS

There were few significant group differences in either the reading-related parameters or VEP latency for any of the test filter conditions. Subjective improvements were noted in most with mTBI (11/12).

CONCLUSIONS

The majority of patients with mTBI chose a tinted filter that resulted in increased visual comfort. While significant findings based on the objective testing were found for some conditions, the subjective results suggest that precision tints should be considered as an adjunctive treatment in patients with mTBI and photosensitivity.

Outcomes of Pediatric Cataract Surgery in the Copperbelt Province of Zambia

PURPOSE

To study the outcomes of pediatric cataract surgeries in children operated on in the Copperbelt Province of Zambia and the barriers to accessing surgery.

METHODS

All children who had congenital, developmental, and traumatic cataracts operated on by lens aspiration, primary posterior capsulotomy, and anterior vitrectomy with posterior chamber intraocular lens implantation from 2012 to 2013 and followed up beyond 6 months were studied. Each child underwent a comprehensive preoperative evaluation. An active, assisted follow-up was done and parents were asked about reasons for delay between presentation and surgery.

RESULTS

One hundred two eyes of 70 children met the inclusion criteria of the study. Preoperatively, 76 of 77 (98.7%) eyes in the congenital and developmental cataract group had presenting visual acuity of worse than 6/60. This improved postoperatively, with 19 (29.7%) eyes having best corrected visual acuity (BCVA) of better than 6/18, 23 (35.9%) having BCVA of 6/24 to 6/60, and 22 (34.4%) having BCVA of worse than 6/60. Older age (P = .005), better preoperative vision (P = .045) at presentation, unilaterality (P = .012), and delay between presentation and surgery (P = .004) were predictors of a better postoperative outcome. On multivariate analysis, only age was significant (P = .025). Distance and cost of travel and surgery were the causes of delay in presentation. In the patients with traumatic cataracts, 17 of 25 (68%) had BCVA of better than 6/18, 6 (24%) had BCVA between 6/24 and 6/60, and 2 (8%) had BCVA of worse than 6/60 at the 6-month follow-up. The most common causes of injury were being struck by sticks and stones (10 children, 25%).

CONCLUSIONS

Visual outcomes after pediatric cataract surgery in Zambia were comparable and satisfactory. Cost of treatment was a barrier, but delay did not adversely affect outcome. [J Pediatr Ophthalmol Strabismus. 2016;53(5):311-317.].

The effect of rehabilitation service use on coping patterns over time among older adults with age-related vision loss

Objective: To enhance our understanding of coping and rehabilitation in the context of adaptation to disability by examining how coping may change over a two-year time period, and how different vision rehabilitation services may affect coping over time.

Design: Longitudinal two-wave study (baseline and two-year follow-up).

Setting: Vision rehabilitation agency.

Subjects: Older adults with visual impairment.

Method: In-person interviews using structured assessments of functional vision loss and functional disability, rehabilitation service use and coping strategies.

Results: Ninety-five people participated in both study waves. Findings showed change in patterns of coping over the two-year period of the study, as participants adjusted to living with age-related vision loss. Although instrumental coping was the only coping mode with evidence for average change (a decrease), affective and escape/distraction strategies showed individual variation in change over time. Rehabilitation use explained variance in coping at time 2 over and above impairment status and coping at time 1. Those who used a greater number of assistive aids between time points were likely to report more instrumental coping at time 2, and those who used counselling between time points were likely to report more affective coping at the two-year follow-up. Finally, those who used more optical aids were likely to report more escape/distraction coping at time 2, whereas those who saw a low vision specialist tended to report less of this type of coping over time.

Conclusions: Findings suggest that rehabilitation interventions can affect coping patterns over time, and that direction and magnitude of such an effect may depend on the type of rehabilitation received.