Confidence in low vision rehabilitation and attitudes towards further learning: A survey of UK optometrists.

PURPOSE: Optometrists are well positioned to help expand low vision (LV) services and improve their availability and accessibility. Determinants of participation in LV service provision must be well understood to facilitate successful service expansion. This survey aimed to investigate optometrists' professional confidence in the delivery of LV services and attitudes towards further learning. METHODS: An online survey was emailed to a sample of College of Optometrists members. Respondents rated their confidence in different areas of core optometric practice; confidence in LV was compared with confidence in other areas. Respondents also rated their confidence in undertaking multiple tasks involved in LV service delivery and in routine optometric practice; confidence was compared between optometrists who do and do not work in a LV service. Attitudes towards learning more about assessing and supporting patients with a vision impairment (VI) were recorded. RESULTS: The survey received 451 recorded responses (15.1% response rate). Optometrists who do not work in a LV service reported significantly lower confidence in LV than in other areas of core optometric practice, whereas optometrists who work in a LV service reported significantly higher confidence in LV than in other areas. Additionally, optometrists who do not work in a LV service reported significantly lower confidence in all tasks involved in LV service delivery than optometrists who work in a LV service (p < 0.001 for all tasks). Approximately 80% of respondents were interested in learning more about assessing and supporting patients with a VI. CONCLUSIONS: Optometrists who do not work in a LV service have relatively low confidence in LV, which could contribute to low motivation to participate in LV service provision. There is sizeable interest in learning more about assessing and supporting patients with a VI, which could help to increase motivation to participate in LV service provision.

International Practice Recommendations for the Recognition and Management of Hearing and Vision Impairment in People with Dementia.

INTRODUCTION: Hearing, vision, and cognitive impairment commonly co-occur in older people. However, the rate of recognition and appropriate management of combined hearing and vision impairment in people with dementia impairment is low. The aim of this work was to codevelop internationally relevant, multidisciplinary practice recommendations for professionals involved in the diagnosis, care, and management of older people with these concurrent conditions. METHODS: We applied consensus methods with professional and lay expert stakeholders, using an adapted version of the World Health Organization Handbook for Guideline Development. The development involved 4 phases and included: (1) collating existing evidence, (2) filling the gaps in evidence, (3) prioritising evidence, and (4) refining the final list of recommendations. Each phase encompassed various methodologies including a review of existing guidelines within the 3 clinical domains, systematic reviews, qualitative studies, a clinical professional consortium, surveys, and consensus meetings with interdisciplinary domain experts. RESULTS: The task force evaluated an initial list of 26 recommendations, ranking them in the order of priority. A consensus was reached on 15 recommendations, which are classified into 6 domains of "awareness and knowledge," "recognition and detection," "evaluation," "management," "support," and "services and policies." Pragmatic options for implementation for each domain were then developed. CONCLUSION: This is the first set of international, interdisciplinary practice recommendations that will guide the development of multidisciplinary services and policy to improve the lives of people with dementia and hearing and vision impairment.

An exploratory study on support for caregivers of people with vision impairment in the UK.

PURPOSE: Many of the UK's 2.5 million individuals living with vision loss receive support from relatives or friends (so-called 'informal caregivers'). However, there is limited understanding of how caregivers of people with visual impairment (PVI) are, or feel, supported by UK healthcare/statutory services and charities. This exploratory study was conducted to explore caregivers' experiences and their suggestions for enhancing support. METHODS: Participants self-identifying as UK-based caregivers of PVI (N = 100) volunteered to undertake an online survey, distributed through charity partners. The survey was comprised of the Client Satisfaction Questionnaire-8 (CSQ-8, a validated, self-report measure of satisfaction with support services), Likert-type questions and two open-ended, free-text questions. Interview participants (N = 22) were then selected from survey respondents, and semi-structured interviews were conducted to focus on caregivers' ideas for improving support. The Framework Method was used for inductive analysis of the free-text question responses and interview data. RESULTS: The mean (SD) CSQ-8 score was 21.60 (7.2), with no significant differences by demographic, relationship or vision-related factors, likely limited by the small subgroup sizes. Qualitative data demonstrated the heterogeneity of participating caregivers' experiences, highlighting the importance of personalised support for caregivers. Many participants advocated enhancing informational, practical, emotional and social support for caregivers, and stressed the importance of accessible services and consistent points of contact to turn to for support and advice. CONCLUSIONS: Although our sample was arguably better connected to support services than the general caregiver population, this study identified concrete suggestions to improve practical, emotional and peer support for caregivers of PVI.

Driving and exceptional cases: Supporting relicensing evaluation in patients whose visual fields fail to meet standards.

PURPOSE: The UK Driver and Vehicle Licensing Agency's (DVLA) visual field criteria mean that homonymous defects close to fixation are not usually acceptable for driving. Here, we illustrate cases where patients with field defects failing to meet standards had their licences revoked but subsequently were permitted to drive again through exceptional case provisions. METHODS: Clinical assessment of two patients with homonymous loss: a 62-year-old man (PWT) with a dense left upper homonymous quadrantanopia secondary to a right occipital lobe stroke and a 48-year-old woman (JC), only aware of right upper homonymous quadrantanopia following routine primary care assessment and subsequently attributed to left middle cerebral artery stroke from perinatal intracranial haemorrhage. RESULTS: PWT's Esterman test showed a significant central defect failing to meet the standard. His subsequent ophthalmic examination was otherwise unremarkable with excellent visual functions. Clinical evidence was provided supporting his relicensing application, and in time, a practical DVLA driving assessment indicated adaptation had been successful, and his licence was restored. JC's defect also failed to meet the standard, and her licence was revoked. Her ophthalmic examination was otherwise unremarkable, and her condition was attributed to a nonprogressive, isolated perinatal event. The DVLA accepted supporting clinical evidence; her subsequent practical driving assessment demonstrated successful adaptation and her licence was also restored. CONCLUSIONS: Conventional visual field tests are not necessarily predictive of real-world driving performance, with drivers' adaptive strategies not being accommodated. In the UK, individuals with visual field loss failing to meet the standard may be eligible for relicensing as exceptional cases if specific criteria can be met. For exceptional cases potentially licensable under these criteria, the DVLA requires clinician support and a satisfactory practical driving assessment. Similar provisions exist internationally. Clinicians need to be aware of the role they may play in such scenarios.

Autism-friendly eyecare: Developing recommendations for service providers based on the experiences of autistic adults.

PURPOSE: People with autism face significant barriers when accessing healthcare services. Eye examinations present unique challenges. Accessibility of this healthcare sector for people with autism has not been investigated previously. The aim of this research was to investigate eye examination accessibility for autistic adults and produce recommendations for autism-friendly eyecare. METHODS: Two qualitative studies were conducted. In Study 1, 18 autistic adults took part in focus groups to elicit their eye examination experiences. Transcripts of the recorded discussions were thematically analysed. Study 1 findings were used to design autism-friendly eye examinations for autistic adults. These were conducted in Study 2. Twenty-four autistic adults participated in these examinations, during which they were interviewed about their experience and how it might be improved by reasonable modifications. Audio recordings of the interviews were content analysed. RESULTS: Knowledge of what to expect, in advance of the eye examination, could greatly reduce anxiety. Participants liked the logical structure of the examination, and the interesting instrumentation used. However, the examination and practice environment did include sensory challenges, due to lights, sound and touch. Changes in practice layout, and interacting with multiple staff members, was anxiety provoking. Participants expressed a need for thorough explanations from the optometrist that outlined the significance of each test, and what the patient was expected to do. CONCLUSION: A number of accessiblity barriers were identified. These suggested that UK eye examinations are not very accessible for autistic adults. Barriers began at the point of booking the appointment and continued through to the dispensing of spectacles. These caused anxiety and stress for this population, but could be reduced with easy-to-implement adaptations. Based on the findings, recommendations are presented here for the whole eyecare team which suggest how more autism-friendly eye examinations can be provided.

Effectiveness of portable electronic and optical magnifiers for near vision activities in low vision: a randomised crossover trial.

PURPOSE: To compare the performance of near vision activities using additional portable electronic vision enhancement systems (p-EVES), to using optical magnifiers alone, by individuals with visual impairment. METHODS: A total of 100 experienced optical aid users were recruited from low vision clinics at Manchester Royal Eye Hospital, Manchester, UK, to a prospective two-arm cross-over randomised controlled trial. Reading, performance of near vision activities, and device usage were evaluated at baseline; and at the end of each study arm (Intervention A: existing optical aids plus p-EVES; Intervention B: optical aids only) which was after 2 and 4 months. RESULTS: A total of 82 participants completed the study. Overall, maximum reading speed for high contrast sentences was not statistically significantly different for optical aids and p-EVES, although the critical print size and threshold print size which could be accessed with p-EVES were statistically significantly smaller (p < 0.001 in both cases). The optical aids were used for a larger number of tasks (p < 0.001), and used more frequently (p < 0.001). However p-EVES were preferred for leisure reading by 70% of participants, and allowed longer duration of reading (p < 0.001). During the study arm when they had a p-EVES device, participants were able to carry out more tasks independently (p < 0.001), and reported less difficulty with a range of near vision activities (p < 0.001). CONCLUSIONS: The study provides evidence that p-EVES devices can play a useful role in supplementing the range of low vision aids used to reduce activity limitation for near vision tasks.

Vision impairment and dual sensory problems in middle age.

PURPOSE: Vision and hearing impairments are known to increase in middle age. In this study we describe the prevalence of vision impairment and dual sensory impairment in UK adults aged 40-69 years in a very large and recently ascertained data set. The associations between vision impairment, age, sex, socioeconomic status, and ethnicity are reported. METHODS: This research was conducted using the UK Biobank Resource, with subsets of UK Biobank data analysed with respect to self-report of eye problems and glasses use. Better-eye visual acuity with habitually worn refractive correction was assessed with a logMAR chart (n = 116,682). Better-ear speech reception threshold was measured with an adaptive speech in noise test, the Digit Triplet Test (n = 164,770). Prevalence estimates were weighted with respect to UK 2001 Census data. RESULTS: Prevalence of mild visual impairment (VA >0.1 logMAR (6/7.5, 20/25) and ≥0.48 (6/18, 20/60)) and low vision (VA >0.48 (6/18, 20/60) and ≥1.3 (6/120, 20/400)) was estimated at 13.1% (95% CI 12.9-13.4) and 0.8% (95% CI 0.7-0.9), respectively. Use of glasses was 88.0% (95% CI 87.9-88.1). The prevalence of dual sensory impairment was 3.1% (95% CI 3.0-3.2) and there was a nine-fold increase in the prevalence of dual sensory problems between the youngest and oldest age groups. Older adults, those from low socioeconomic and ethnic minority backgrounds were most at risk for vision problems. CONCLUSIONS: Mild vision impairment is common in middle aged UK adults, despite widespread use of spectacles. Increased likelihood of vision impairment with older age and with ethnic minorities is of concern given ageing and more ethnically diverse populations. Possible barriers to optometric care for those from low socioeconomic and ethnic minority backgrounds may require attention. A higher than expected prevalence of dual impairment suggests that hearing and vision problems share common causes. Optometrists should consider screening for hearing problems, particularly among older adults.

Providing capacity in glaucoma care using trained and accredited optometrists: A qualitative evaluation.

INTRODUCTION: The role of optometrists in glaucoma within primary and secondary care has been well described. Whilst many studies examined safety and clinical effectiveness, there is a paucity of qualitative research evaluating enablers and barriers for optometrists delivering glaucoma care. The aims of this study are to investigate qualitatively, and from a multi-stakeholder perspective whether optometric glaucoma care is accepted as an effective alternative to traditional models and what contextual factors impact upon their success. METHODS: Patients were recruited from clinics at Manchester Royal Eye Hospital and nationally via a Glaucoma UK registrant database. Optometrists, ophthalmologists, and other stakeholders involved in glaucoma services were recruited via direct contact and through an optometry educational event. Interviews and focus groups were recorded and transcribed anonymously, then analysed using the framework method and NVivo 12. RESULTS: Interviews and focus groups were conducted with 38 participants including 14 optometrists and 6 ophthalmologists (from all 4 UK nations), and 15 patients and 3 commissioners/other stakeholders. Themes emerging related to: enablers and drivers; challenges and barriers; training; laser; professional practice; the role of other health professionals; commissioning; COVID-19; and patient experience. CONCLUSION: Success in developing glaucoma services with optometrists and other health professionals is reliant on multi-stakeholder input, investment in technology and training, inter-professional respect and appropriate time and funding to set up and deliver services. The multi-stakeholder perspective affirms there is notable support for developing glaucoma services delivered by optometrists in primary and secondary care, with caveats around training, appropriate case selection and clinical responsibility.

Risk of Falls and Fractures in Individuals With Cataract, Age-Related Macular Degeneration, or Glaucoma.

Importance: Three leading disease causes of age-related visual loss are cataract, age-related macular degeneration (AMD), and glaucoma. Although all 3 eye diseases have been implicated with falls and fracture risk, evidence is mixed, with the contribution of different eye diseases being uncertain. Objective: To examine whether people with cataract, AMD, or glaucoma have higher risks of falls or fractures than those without. Design, Setting, and Participants: This cohort study was a population-based study in England using routinely collected electronic health records from the Clinical Practice Research Datalink (CPRD) GOLD and Aurum primary care databases with linked hospitalization and mortality records from 2007 to 2020. Participants were people with cataract, AMD, or glaucoma matched to comparators (1:5) by age, sex, and general practice. Data were analyzed from May 2021 to June 2023. Exposures: For each eye disease, we estimated the risk of falls or fractures using separate multivariable Cox proportional hazards regression models. Main Outcomes: Two primary outcomes were incident falls and incident fractures derived from general practice, hospital, and mortality records. Secondary outcomes were incident fractures of specific body sites. Results: A total of 410 476 people with cataract, 75 622 with AMD, and 90 177 with glaucoma were matched (1:5) to 2 034 194 (no cataract), 375 548 (no AMD), and 448 179 (no glaucoma) comparators. The mean (SD) age was 73.8 (11.0) years, 79.4 (9.4) years, and 69.8 (13.1) years for participants with cataract, AMD, or glaucoma, respectively. Compared with comparators, there was an increased risk of falls in those with cataract (adjusted hazard ratio [HR], 1.36; 95% CI, 1.35-1.38), AMD (HR, 1.25; 95% CI, 1.23-1.27), and glaucoma (HR, 1.38; 95% CI, 1.35-1.41). Likewise for fractures, there were increased risks in all eye diseases, with an HR of 1.28 (95% CI, 1.27-1.30) in the cataract cohort, an HR of 1.18 (95% CI, 1.15-1.21) for AMD, and an HR of 1.31 (95% CI, 1.27-1.35) for glaucoma. Site-specific fracture analyses revealed increases in almost all body sites (including hip, spine, forearm, skull or facial bones, pelvis, ribs or sternum, and lower leg fractures) compared with matched comparators. Conclusions and Relevance: The results of this study support recognition that people with 1 or more of these eye diseases are at increased risk of both falls and fractures. They may benefit from improved advice, access, and referrals to falls prevention services.

Investigating eye examination-related anxiety in autistic adults.

CLINICAL RELEVANCE: It is important to investigate whether anxiety is a barrier to accessing eye examinations for autistic adults, because existing research suggests this population are more likely to develop ophthalmic abnormalities. BACKGROUND: Anxiety influences healthcare accessibility for autistic people without learning disabilities. Previous qualitative studies by the research team, with a small sample of autistic adults, have indicated several aspects of eyecare services which cause anxiety. Considering the limited existing research suggesting autistic individuals are more likely to develop ophthalmic abnormalities, this study explored whether this population more widely experiences anxiety when accessing eye examinations. METHODS: A total of 322 UK-based autistic adults completed the Optometric Patient Anxiety Scale (OPAS) online, between July and December 2020. Rasch analysis was used to validate this questionnaire for an autistic adult population, and compare optometric anxiety levels to the general population. RESULTS: Item infit (0.77 to 1.39) and outfit (0.78 to 1.33) values, the person separation index (2.64), and item (0.99) and person (0.97) reliability coefficients suggested that all 10 items in the OPAS are useful to assess optometric anxiety in an autistic adult population. Item probability curves confirmed the response scale to be appropriate. A comparison of optometric anxiety between the autistic population in the current study and a general population in previous work found no statistically significant difference. CONCLUSION: The OPAS is a statistically valid tool for use in the autistic adult population. It appears to suggest no significant difference in optometric anxiety between the autistic adult and general population. However, it is possible that it underestimates the true optometric anxiety of autistic adults since the items do not include some of the anxiety provoking factors for this population which have been indicated in previous studies by the research team.

What do individuals with visual impairment need and want from a dialogue-based digital assistant?

CLINICAL SIGNIFICANCE: Optometrists are well-placed to provide helpful advice and guidance to patients with visual impairment but may not know how best to do this. The availability of a reliable and comprehensive conversational agent to which patients could be directed would be a valuable supplement to clinical intervention. BACKGROUND: The Artificial Intelligence in Visual Impairment (AIVI) Study is a proof-of-concept study to investigate whether ongoing information support for people with visual impairment (VI) can be provided by a dialogue-based digital assistant. The phase of the AIVI Study reported here explored the different dimensions of the information-seeking behaviour of individuals with VI: in particular, their need for information, the methods for obtaining it at present, and their views on the use of a digital assistant. METHODS: Qualitative data were collected from 120 UK-resident adults who responded to an online survey who were either visually impaired (86.7%), a carer or family member of someone with VI (5.8%), or a professional involved in the support of those with VI (7.5%). In addition, 10 in-depth 1:1 semi-structured interviews explored opinions in more detail. Thematic analysis was used to analyse the findings. RESULTS: Analysis of information needs identified 7 major themes: ocular condition; equipment, technology and adaptations; daily activities; registration; finance/employment; emotional support; and support for the carer. Participants used a wide variety of methods to access information from many sources and explained the barriers to access. Participants accepted the merit of a dialogue system aiding in a goal-directed search for specific information, but expressed reservations about its abilities in other areas, such as providing emotional support. CONCLUSIONS: Participants highlighted potential benefits, limitations, and requirements in using a digital assistant to access information about VI. These findings will inform the design of dialogue systems for populations with VI.

What support do caregivers of people with visual impairment receive and require? An exploratory study of UK healthcare and charity professionals' perspectives.

BACKGROUND: Previous research has established that some informal caregivers (relatives/friends) of people with visual impairment (PVI) may require support themselves. However, there is limited understanding of how healthcare services and sight charities in the UK currently support caregivers. This study was therefore conducted to explore what support, information, and advice healthcare and charity professionals (HCCPs) currently provide for caregivers, and which additional support HCCPs would recommend in order to benefit caregivers. METHODS: HCCPs filled out an online survey, distributed among UK-based professional bodies and charity partners. Of 104 individuals who consented to participate, 68 (65%) HCCPs completed the survey in September-November 2019. Participants responded to Likert-type questions about how they interact with and support caregivers of PVI. Thirty-eight (56%) participants provided responses to open-ended questions about improving support for caregivers; qualitative analysis was conducted using the Framework Method. RESULTS: The survey showed that caregiver support activities most commonly undertaken related to onward signposting (90% (95% CI: 82-97%) of participants), or providing information about low vision aids and adaptations (85% (95% CI: 77-94%)), compared to activities focused on broader caregiver wellbeing. In open-ended responses, HCCPs highlighted the difficulties caregivers face in navigating an under-resourced and complex system. They recommended improving coordination and accessibility of information, as well as provision of emotional support and tangible assistance such as respite care and financial support. CONCLUSIONS: The study suggests that HCCPs perceive significant unmet needs among caregivers of PVI, and would welcome further resources, information, and training to support caregivers.

The effect of simulated visual impairment on speech-reading ability.

PURPOSE: Speech-reading is the ability to recognise certain sounds visually, using both the movements of the speaker's mouth, plus other sources of visual information, such as gestures and body language, facial expressions and situational clues. This study aimed to determine the effect of mild degrees of visual impairment on speech-reading ability. METHOD: A group of 15 normally-sighted subjects was assessed with different levels of simulated visual loss using occlusion foils, in the presence of constant background noise to simulate hearing loss. The visual impairments created ranged from 20 to 13 dB log contrast sensitivity (contrast thresholds 1-5%) (measured using the backlit Melbourne Edge Test) with acuity dropping from 6/6 to 6/24 (logMAR 0.0-0.6). The speech-reading ability with simulated impairment and noise was quantified as the number of words recognised correctly when watching a video of an actor speaking meaningful sentences. RESULTS: The introduction of the mildest simulated visual impairment (VA 6/6 logMAR 0.0; contrast sensitivity 20 dB, contrast threshold 1%) was sufficient to cause a statistically significant reduction in speech-reading ability (t-test, p < 0.001), and as the level of visual impairment was increased, the speech-reading ability became progressively worse throughout the range of impairments tested. CONCLUSIONS: This study shows that if hearing is compromised, then an observer's speech-reading ability is sensitive to changes in vision. It is likely that visual loss will have consequences for speech-reading ability. This will be particularly relevant to the elderly population who are often found to have a dual sensory loss that causes compromise to both visual and auditory sensory reception. Some of the difficulties in communication reported by the elderly with reduced hearing could be visual as opposed to auditory in origin.

What support is beneficial for caregivers of individuals with vision impairment?

Previous studies and reviews have documented the stress and challenges that may be associated with providing informal care for individuals with vision impairment (IVI). This scoping review was therefore conducted in order to synthesise published literature about forms of support which may benefit the informal caregivers of both adults and children with vision impairment (VI), and to identify research gaps in the support available for this population. A systematic literature search was carried out using CINAHL, Medline, PsycINFO and PsycARTICLES, followed by citation tracking. A total of 23 published studies met the eligibility criteria and were included in the review. The included studies focused on: exploring caregiver support needs (8/23); novel interventions supporting caregivers of IVI (10/23); evaluating usual care (2/23); and exploring how treatment for IVI directly impacts the caregiver (3/23). Overall, support for caregivers of IVI is a relatively new research topic, with no eligible studies identified before 1999. Twelve of the 23 studies (52%) focused on support for caregivers of adults with VI, while 11 (48%) focused on support for caregivers of children with VI. The studies illustrate that support groups may generally help to improve caregivers' knowledge and awareness of VI, although benefits for emotional wellbeing are more modest. Support interventions for parents of children with VI appear to reduce stress effectively; however, evidence regarding the value of interventions for caregivers of adults with vision impairment is less clear, partly due to small samples and a lack of standardised, comparable outcome measures. Caregivers often express a need for better information about the condition of the IVI, even when information is apparently available. Further research is required comparing the benefits of different support modalities for caregivers of people with VI over longer follow-up periods.

Visual Sensory Experiences From the Viewpoint of Autistic Adults.

Although previous research has investigated altered sensory reactivity in autistic individuals, there has been no specific focus on visual sensory experiences, particularly in adults. Using qualitative methods, this study aimed to characterize autistic visual sensory symptoms, contextualize their impact and document any associated coping strategies. A total of 18 autistic adults took part in four focus groups which involved questions around visual experiences, the impact of these on daily life, and strategies for their reduction. Transcripts of each session were thematically analyzed allocating six key themes. Participants described a range of visual hypersensitivities, including to light, motion, patterns and particular colors, which contributed to distraction and were frequently part of a wider multisensory issue. Such experiences had significant negative impacts on personal wellbeing and daily life with participants describing fatigue, stress and hindrances on day-to-day activities (e.g., travel and social activities). However, the degree of understanding that participants had about their visual experiences influenced their emotional response, with greater understanding reducing concern. Participants employed a variety of coping strategies to overcome visual sensory experiences but with varied success. Discussions also highlighted that there may be a poor public understanding of sensory issues in autism affecting how well autistic individuals are able manage their sensory symptoms. In summary, autistic adults expressed significant concern about their visual experiences and there is a need to improve understanding of visual experiences on a personal and public level as well as for developing potential support.

Clinical impairment measures and reading performance in a large age-related macular degeneration group.

PURPOSE: To investigate the relationship between clinical impairment measures and reading performance in a large population with age-related macular degeneration. METHODS: The following clinical measures were evaluated on 243 patients with age-related macular degeneration: better eye distance visual acuity (ETDRS chart); threshold near word reading acuity (Bailey-Lovie Word Reading chart); maximum reading speed and critical print size (MNREAD chart); letter contrast sensitivity (Pelli-Robson); and kinetic perimetry (Bjerrum screen) to determine the nearest non-scotomatous point to fovea (NNPF; in degrees) and the central scotoma area (mm2). RESULTS: Distance acuity correlated well to threshold near word acuity (r = 0.71), but word acuity was usually poorer. Critical print size was strongly related (p < 0.001) to near visual acuity (r2 = 0.31 and beta = 0.47) and was poorer than threshold near word visual acuity by a mean difference of -0.41 (range, -1.10 to 0.34), which represents a mean acuity reserve of 2.5:1. On single regression, distance (p < 0.0001, r2 = 0.35, and beta = -102.37) and near acuities (p < 0.0001, r2 = 0.52, beta = -126.53), critical print size (p = 0.0001, r2 = 19, and beta = 0.002), contrast sensitivity (p < 0.0001, r2 = 19, and beta = 79.47), scotoma size (p = 0.006, r2 = 12, and beta = -0.04), and NNPF (p = 0.001, r2 = 12, and beta = -4.39) were all highly significantly related to reading speed although these predicted only a low percentage of variance. Best prediction of reading speed was obtained on multiple regression, where NNPF and near word acuity explained 60% of the variance (p < 0.0001). CONCLUSIONS: Optimal prediction of reading speed with clinical parameters appears to be based on the combination of near word acuity and scotoma area, explaining 60% of the variance. Other factors not measured in this study are likely to account for the rest of the prediction.

Collinear facilitation and contour integration in autistic adults: Examining lateral and feedback connectivity.

Alongside difficulties with communication and social interaction, autism is often accompanied by unusual sensory and perceptual experiences including enhanced visual performance on tasks that involve separating local parts from global context. This superiority may be the result of atypical integrative processing, involving feedback and lateral connections between visual neurons. The current study investigated the integrity of these connections in autistic adults by examining two psychophysics tasks that rely on these processes - collinear facilitation and contour integration. The relative contribution of feedback and lateral connectivity was studied by altering the timing of the target relative to the flankers in the collinear facilitation task, in 16 autistic and 16 non-autistic adults. There were no significant differences in facilitation between the autistic and non-autistic groups, indicating that for this task and participant sample, lateral and feedback connectivity appear relatively intact in autistic individuals. Contour integration was examined in a different group of 20 autistic and 18 non-autistic individuals, for open and closed contours to assess the closure effect (improved detection of closed compared to open contours). Autistic individuals showed a reduced closure effect at both short (150 ms) and longer (500 ms) stimulus presentation durations that was driven by better performance of the autistic group for the open contours. These results suggest that reduced closure in a simple contour detection paradigm is unlikely to be due to slower global processing. Reduced closure has implications for understanding sensory overload by contributing to reduced figure-ground segregation of salient visual features.

Does an iPad fixation disparity test give equivalent results to the Mallett near fixation disparity test?

BACKGROUND: Various instruments have been developed to measure aligning prism, the prism that eliminates a fixation disparity (associated heterophoria). This includes the established Mallett near vision unit and recently developed Thomson Vision Toolbox on the iPad. With no previous research investigating the agreement between these instruments, practitioners may question if they can be used interchangeably. METHODS: 80 participants underwent near vision testing with the Mallett unit and iPad fixation disparity test. Data were analysed in four ways to investigate the agreement of the two instruments. RESULTS: Many participants reported no fixation disparity (horizontally 46.25%, vertically 82.5%), or non-significant aligning prism (horizontally 70%, vertically 97.5%), on both instruments. The iPad revealed a larger range of aligning prism results horizontally, 6Δ base out to 15Δ base in; the Mallett unit produced a larger range of results vertically, 1Δ base up to 3.5Δ base down. More participants required a significant aligning prism on the Mallett unit horizontally and vertically. Wilcoxon signed rank analysis found that the difference in aligning prism was not statistically significant (p=0.357 horizontally, p=0.236 vertically), but 95% limits of agreement revealed clinically significant differences between the instruments. CONCLUSION: Although the measured differences between the instruments are not significant in a Wilcoxon analysis, a Bland & Altman approach shows them to be in some cases clinically unacceptable, therefore the instruments should not be used interchangeably. Previous research indicates that the Mallett unit performs reasonably well at detecting symptomatic individuals and determining a prismatic correction that is likely to be helpful. Further research is required to determine the performance of the iPad test in these functions and to assess the reproducibility of both instruments.