Australian children with cerebral visual impairment: using what we know now to improve future approaches.

PURPOSE: Little has been reported on Australian children with Cerebral Vision Impairment (CVI). This paper aims to present the outcome of an audit focussed on children with the primary diagnosis of CVI, using findings from the Australian Childhood Vision Impairment Register (ACVIR). METHODS: Records on 132 children (49% girls, 51% boys) from ACVIR data gathered from both the child's parent/guardian and their eye health professional were reviewed. The child's demographics, level of vision impairment, birth history, diagnostic journey, secondary ocular diagnoses, comorbidities and low vision support were analyzed. Several correlations were investigated using a Kendall's tau-b analysis including the relationship between vision and age of diagnosis; level of vision and developmental delay; and age of suspicion of visual impairment and age of diagnosis. RESULTS: The most common level of visual impairment was blindness (39%), and most children were suspected and diagnosed of visual impairment in the first 6 months of life. The majority of children were born full term (72%), weighing >2000gms (84%). Nearly half of the cohort of children (48%) had a secondary ocular diagnosis with 44% having nystagmus. The majority of children (80%) had additional health problems, and 85% of children had additional disabilities, with 79% having developmental delay. CONCLUSION: While the findings of this audit cannot be generalized to a wider population of Australian children with CVI, the outcome encourages continued discussion on CVI, to explore comprehensive assessment approaches which facilitate timely and accurate diagnosis.

Commentary: Profiling Children With Cerebral Visual Impairment (CVI) Using Multiple Methods of Assessment to Aid in Differential Diagnosis.

PROFILING CHILDREN WITH CEREBRAL VISUAL IMPAIRMENT USING MULTIPLE METHODS OF ASSESSMENT TO AID IN DIFFERENTIAL DIAGNOSIS: Amanda H. Lueck , Gordon N. Dutton , Sylvie Chokron Seminars in Pediatric Neurology Volume 31, October 2019, Pages 5-14 Cerebral (cortical) visual impairment (CVI), the primary cause of visual impairment in chil dren in high-income countries, is increasing globally due to improved life-saving measures for premature and full-term infants. Yet the consequences of this condition are only begin ning to be understood and addressed. According to the topography, site, and the extent of the pathology, the deficit may variably concern central visual functions, visual field, percep tion of movement, visual analysis, visual exploration, attention, or visual memory, as well as visual guidance of movement. Each affected child has a unique clinical picture, which needs to be identified and individually profiled. This is probably the underlying reason that CVI is commonly underdiagnosed or misdiagnosed, especially in children, and, as a consequence, the full range of potential behavioral outcomes are not identified and adequately addressed. The present paper shows how the use of multiple methods of assessment can improve understanding of children with CVI.

Color perception on Ishihara plates with red lenses in subjects with low vision due to retinal diseases.

Purpose: This study aimed to evaluate color perception (CP) changes on Ishihara plates following red-tinted contact lenses in subjects with low vision (LV) from retinal diseases. Methods: A cross-sectional observational study without control involved 84 subjects, aged 20-70 years, having LV from retinal diseases to examine CP changes following wearing red-tinted contact lenses. The subjects viewed Ishihara plates, with each eye separately, before and after wearing red lenses in two categories: "plates 1-21" and "plates 22-25". Change in CP with the use of a red lens was the primary outcome measure. Results: There was a significant increase in the number of plates read in both categories, that is, plates 1-21 (P = 0.002) and plates 22-25 (P = 0.032), the latter being used to diagnose the red-green defects. Although 70 eyes could read both digits on plates 22-25 and appeared to have normal color vision (CV) at baseline, this number rose to 99 eyes following the use of red-tinted lenses. There was a significant change in the type of CP (red defect/green defect/normal/undefined defect) (P = 0.022) with the application of a red-tinted lens. Conclusions: The use of red-tinted lenses caused a significant increase in the number of plates read, increased the number of subjects who appeared normal on plates 22-25, and significantly changed CP of LV subjects. These lenses can be a valuable aid for LV subjects. Although Ishihara plates can diagnose only red-green defects, further studies on CV testing techniques that detect both red-green and blue-yellow CV defects are recommended.

Self-Reported Visual Ability Versus Task Performance in Individuals With Ultra-Low Vision.

Purpose: Visual functioning questionnaires are commonly used as patient-reported outcome measures to estimate visual ability. Performance measures, on the other hand, provide a direct measure of visual ability. For individuals with ultra-low vision (ULV; visual acuity (VA) <20/1600), the ultra-low vision visual functioning questionnaire (ULV-VFQ) and the Wilmer VRI-a virtual reality-based performance test-estimate self-reported and actual visual ability, respectively, for activities of daily living. But how well do self-reports from ULV-VFQ predict actual task performance in the Wilmer VRI? Methods: We administered a subset of 10 matching items from the ULV-VFQ and Wilmer VRI to 27 individuals with ULV. We estimated item measures (task difficulty) and person measures (visual ability) using Rasch analysis for ULV-VFQ and using latent variable signal detection theory for the Wilmer VRI. We then used regression analysis to compare person and item measure estimates from self-reports and task performance. Results: Item and person measures were modestly correlated between the two instruments, with r2 = 0.47 (P = 0.02) and r2 = 0.36 (P = 0.001), demonstrating that self-reports are an imperfect predictor of task difficulty and performance. Conclusions: While self-reports impose a lower demand for equipment and personnel, actual task performance should be measured to assess visual ability in ULV. Translational Relevance: Visual performance measures should be the preferred outcome measure in clinical trials recruiting individuals with ULV. Virtual reality can be used to standardize tasks.

Development and Validation of the Low Vision Severely Constricted Peripheral Eyesight (LV-SCOPE) Questionnaire.

PURPOSE: To develop and validate a novel patient-reported outcome (PRO) measure to assess vision-related functioning in individuals with severe peripheral field loss (PFL). DESIGN: Prospective outcome measure development/validation study. METHODS: A 127-item questionnaire was developed based on a prior qualitative interview study. A total of 116 participants with severe PFL due to retinitis pigmentosa (RP) or glaucoma were recruited at the Kellogg Eye Center and completed the Likert-scaled telephone-administered questionnaire. Included participants had a horizontal extent of their visual field <20 degrees (RP) or a mixed or generalized stage 4 to 5 defect using the Enhanced Glaucoma Staging System (glaucoma) in the better seeing eye (or in 1 eye if the fellow eye visual acuity was <20/200). Response data were analyzed using exploratory factor analysis and Rasch modeling. Poorly functioning items were eliminated, confirmatory factor analysis was used to ensure scale unidimensionality, and the model was refit to produce the final instrument. RESULTS: The final Low Vision Severely Constricted Peripheral Eyesight (LV-SCOPE) Questionnaire contains 53 items across 6 domains: mobility, object localization, object recognition, reading, social functioning, and technology. There were 74 items removed because of high missingness, poor factor loadings, low internal consistency, high local dependency, low item information, item redundancy, or differential item functioning. Using Rasch item calibrations, person ability scores could be calculated for each of the 6 unidimensional LV-SCOPE domains with good test-retest stability. CONCLUSIONS: The LV-SCOPE Questionnaire provides a valid and reliable measure of vision-related functioning across 6 key domains relevant to individuals with severe PFL. Findings support the clinical utility of this psychometrically valid instrument.

Prevalence and causes of visual impairment in Dongaria indigenous (tribal) community. Tribal Odisha eye disease study # 12.

Purpose: To document the spectrum and magnitude of eye disorders and visual impairment in the Dongaria-a Particularly Vulnerable Tribal Group in the Rayagada district of Odisha, India. Methods: A door-to-door screening protocol included a record of basic health parameters, visual acuity for distance, and near and flashlight examination of the eyes. Spectacles were dispensed to those who improved; those who failed the screening were referred to fixed (primary and secondary) eye care centers. Results: We examined 89% (n = 9872/11,085) of people who consented for screening. The mean age was 25.5 ± 18.8 years; 55% (n = 5391) were female; 13.8% (n = 1361) were under-five children, and 39% (n = 3884) were 6 to 16 years. 86% (n = 8515) were illiterate. 12.4% (n = 1224) were visually impaired, of which 9.9% had early moderate VI, and 2.5% had severe VI and blindness. Uncorrected refractive error was detected in 7.5% (n = 744) and cataracts in 7.6% (n = 754); among the adults, 41.5% (n = 924/2227) had presbyopia. In children, 20% (n = 790) had vitamin A deficiency, 17% (n = 234) had global acute malnutrition, and 18% (n = 244) were stunted for their age. Almost two-thirds (62%, n = 6144) confirmed habitual intake of alcohol, and 4% (n = 389) of adults had essential hypertension. Following the screening, 43.5% (n = 837) of referred patients reported to the fixed centers, and 55% (134/243) of people advised underwent cataract surgery. Spectacles were dispensed to 1496 individuals. Conclusion: Visual impairment and malnutrition are high in Dongaria indigenous community. Permanent health facilities and advocacy would improve this community's health and health-seeking behavior.

Further Validation of Comfortable Print Size as a Parameter for Clinical Low-Vision Assessment.

Purpose: Comfortable print size (CfPS) has been proposed as a clinical alternative to deriving critical print size (CPS) in the assessment of reading function of vision-impaired patients. This study aimed to assess the repeatability of CfPS and to compare assessment duration and values to CPS measures and acuity reserves. Methods: Thirty-four adults with vision impairment had their reading function assessed. Two assessments of CfPS were made by asking, "What is the smallest print size that you would find comfortable using?" Reading parameters including CPS were determined using the MNREAD card chart and MNREAD app. Results: CfPS was quicker to assess (mean ± SD, 144 ± 77 seconds) than the MNREAD card (231 ± 177 seconds) or app (285 ± 43 seconds). Within-session repeatability of CfPS showed no significant bias or variation across the functional range and limits of agreement (LoA) of ±0.09 logMAR. CfPS values were 0.10 logMAR larger than card CPS values, but no different from app CPS values, with LoA of ±0.43 to 0.45 logMAR. Acuity reserve (comparing CfPS to card reading acuity) was 1.9:1 on average, with a maximum of 5.0:1. Conclusions: CfPS offers a quick, repeatable, and individualized clinical measure of the print size required for sustained reading that reflects CPS values obtained by more traditional measures. Translational Relevance: CfPS is an appropriate clinical measure of reading function to use in determining the magnification requirements of vision impaired patients for sustained reading tasks.

Development of The Chinese Version of Ultra-Low Vision Visual Functioning Questionnaire-150.

Purpose: The purpose of this study was to develop the Chinese version of Ultra-Low Vision Visual Functioning Questionnaire-150 (ULV-VFQ-150) and evaluate its psychometric function. Methods: A standardized procedure for the translation of ULV-VFQ-150 was carried out, including the forward translation, consistency check, back translation, back review, and coordination. Participants with ultra-low vision (ULV) were recruited for the questionnaire survey. Psychometric characteristics were evaluated using Rasch analysis based on Item Response Theory (IRT), and some items were revised and proofread accordingly. Results: In total, 70 out of 74 responders completed the Chinese ULV-VFQ-150, of which 10 were excluded because their vision did not meet the criterion of ULV. Therefore, 60 valid questionnaires were analyzed (valid response rate = 81.1%). The average age of eligible responders was 49.0 years (standard deviation = 16.0), with 35% female subjects (21/60). The person measures (ability) ranged from -1.7 to +4.9 logits, and the item measures (difficulty) ranged from -1.6 to +1.2 logits. The mean value of item difficulty and personnel ability were 0.00 and 0.62 logits, respectively. The reliability index was 0.87 for items and 0.99 for persons, and the overall fit is good. The items conform to unidimensionality as indicated by principal component analysis of the residuals. Conclusions: The Chinese version of ULV-VFQ-150 is a reliable questionnaire for evaluating both visual function and functional vision in people with ULV in China. Translational Relevance: The Chinese version of ULV-VFQ-150 is a new assessment of the visual function of people with ULV in China.

Measuring visual information gathering in individuals with ultra low vision using virtual reality.

People with ULV (visual acuity ≤ 20/1600 or 1.9 logMAR) lack form vision but have rudimentary levels of vision that can be used for a range of activities in daily life. However, current clinical tests are designed to assess form vision and do not provide information about the range of visually guided activities that can be performed in daily life using ULV. This is important to know given the growing number of clinical trials that recruit individuals with ULV (e.g., gene therapy, stem cell therapy) or restore vision to the ULV range in the blind (visual prosthesis). In this study, we develop a set of 19 activities (items) in virtual reality involving spatial localization/detection, motion detection, and direction of motion that can be used to assess visual performance in people with ULV. We estimated measures of item difficulty and person ability on a relative d prime (d') axis using a signal detection theory based analysis for latent variables. The items represented a range of difficulty levels (- 1.09 to 0.39 in relative d') in a heterogeneous group of individuals with ULV (- 0.74 to 2.2 in relative d') showing the instrument's utility as an outcome measure in clinical trials.

Prevalence and causes of low vision in a population-based study on childhood visual impairment in North India (CHVI 4).

Purpose: The present study was a population-based study to determine the prevalence and causes of low vision in children less than 16 years in North India. Methods: This cross-sectional study was conducted in 40 clusters of urban Delhi. Children aged less than 16 years underwent visual acuity screening using age-appropriate visual acuity charts. All children with visual acuity of <6/12 in any eye in the age group between 3 and 15 years and inability to follow the light in age less than 3 years were referred for detailed ophthalmic examination in a centrally based clinic. Cycloplegic examination and best-corrected visual acuity (BCVA) were assessed. They were examined by an ophthalmologist to determine the prevalence and causes of functional low vision (FLV). The prevalence of FLV was compared with other population-based studies across India and other parts of the world. Results: Amongst 20,955 children examined for visual acuity, 789 children were referred to the central clinic for detailed ophthalmic examination. The overall prevalence of low vision was 0.62 per 1,000 children (95% confidence interval [CI] 0.12-1.90). The main anatomical cause of low vision was retinal abnormalities. Conclusion: Although the prevalence of children with low vision decreased as compared to previous population-based studies. There is an important need to create awareness among parents on appropriate and timely usage of low-vision devices (LVDs) at an affordable cost to improve the visual quality in children with low vision.

Prevalence and causes of visual impairment and blindness in Lao People's Democratic Republic: the Vientiane Eye Study.

AIMS: To determine the prevalence and causes of visual impairment and blindness in Vientiane Province, the Lao People's Democratic Republic (Lao PDR). METHODS: We conducted a population-based, cross-sectional study of 1264 participants aged 40 years and older from urban and rural areas of Vientiane Province. The ophthalmic examination included presenting and pinhole Snellen visual acuity (VA) with an illiterate E chart, slit-lamp examination of the anterior segment and dilated stereoscopic fundus examination. Visual impairment and blindness were defined by both presenting and pinhole VA based on the better eye according to WHO criteria: VA worse than 6/12 to 6/18 for mild impairment, VA worse than 6/18 to 6/60 for moderate impairment, VA worse than 6/60 to 3/60 for severe impairment and VA worse than 3/60 for blindness. RESULTS: Comprehensive ophthalmic examinations were performed on 1264 participants (77.8% participation rate). Population-weighted prevalence of presenting bilateral blindness was 1.4% (95% CI 0.8 to 2.0) and bilateral visual impairment was 22.4% (95% CI 14.7 to 30.1). After pinhole correction, the corresponding prevalence of blindness was 1.3% (95% CI 0.8 to 2.0) and that of visual impairment was 12.6% (95% CI 8.2 to 16.9). Cataract was the leading cause of presenting bilateral blindness (52.9%), whereas uncorrected refractive error was the predominant cause of presenting visual impairment (40.3%). CONCLUSIONS: Visual impairment and blindness remain major public health problems in Lao PDR. There is an ongoing need to fund ophthalmic care resources and community education programmes to improve access to healthcare in this region.

Prevalence of diabetic retinopathy and reduced vision among indigenous Australians in the nurse-led integrated Diabetes Education and Eye Screening study in a regional primary care clinic.

BACKGROUND: Nationally, Indigenous Australians are more likely to have diabetes and diabetic retinopathy (DR) than non-Indigenous Australians. However, the prevalence of DR and impaired vision in regional primary care settings is unclear. AIM: To describe the prevalence and severity of DR and presenting vision level among Indigenous Australian adults with diabetes attending an indigenous primary care clinic in regional Australia. METHODS: Participants underwent nurse-led retinal imaging and DR screening with offsite retinal grading in the integrated Diabetes Education and Eye Screening (iDEES) project implemented at a regional indigenous primary healthcare setting between January 2018 and March 2020. RESULTS: Of 172 eligible adults, 135 (79%) were recruited and screened for DR and vision level. The median age was 56 (46-67) years, 130 (96%) had type 2 diabetes of median (interquartile range) duration 6 (2-12) years and 48 (36%) were male. Images from 132 (97.8%) participants were gradable. DR was present in 38 (29%) participants: mild non-proliferative in 33 (25%); moderate-severe in three (2.5%); and sight-threatening two (1.5%). Subnormal presenting vision was present in 33%. CONCLUSIONS: A nurse-led model of care integrating diabetes eye screening and education at a single visit was successful at recruiting Indigenous Australian adults with diabetes, screening their vision and acquiring a high rate of gradable images. Even for a short duration of known diabetes, DR was present in three out of 10 patients screened.

Visual impairment due to age-related macular degeneration during 40 years in Finland and the impact of novel therapies.

PURPOSE: To evaluate the changes in visual impairment (VI) due to age-related macular degeneration (AMD) during the past 40 years and the impact of novel therapies at population level. METHODS: In this nationwide register-based study, we assessed the incidence, prevalence, severity, and onset age of VI due to AMD based on the Finnish Register of Visual Impairment data from 1980 to 2019. Our data included 30 016 visually impaired persons with AMD as the main diagnosis for VI. The number of persons treated with intravitreal injections in Finland was obtained from hospital data kept by the Finnish Institute for Health and Welfare. RESULTS: Between the 1980s and the 2010s, the incidence of reported VI doubled; however, this increase has stagnated in the 2010s. Since 2012, the prevalence of reported VI has decreased. The number of patients treated with intravitreal injections showed a 40-fold increase during 2005-2019. The severity of reported VI has decreased whereas the mean age at the onset of reported VI has increased during the 40 years. The age-adjusted incidence and prevalence of reported VI were significantly higher in females in comparison to males in all decades. CONCLUSION: Increase in the incidence and prevalence of VI due to AMD in the past decades has stagnated and shifted to older age in the 2010s when therapies for exudative class became commonly available. Furthermore, the prognosis of VI has improved during the past 40 years. These positive trends are likely contributable to improved diagnostic tools, earlier diagnoses, and new therapy options.

Concept Mapping to Identify Content for a Performance-Based Measure of Low Luminance Vision-Related Activities of Daily Living.

Purpose: The purpose of this study was to identify low luminance activities of daily living (ADL) relevant to adults with vision impairment using a concept-mapping approach. Methods: "Group concept mapping" was utilized to identify specific ADLs that persons with vision impairment find challenging under low light conditions. In the first "brainstorming" phase, 24 adults with vision impairment from a range of eye conditions (mean age = 73 years, SD = 14 years) and 26 international low vision experts (mean experience = 22, SD = 11 years) generated statements to the focus prompt, "Thinking as broadly as possible, generate a list of statements detailing specific day-to-day activities a person with vision impairment might find challenging under low light conditions, such as in a poorly lit room or outside at dusk." In the second phase, participants sorted activities by similarity and rated the importance of each activity. Multidimensional scaling and hierarchical cluster analysis were applied to produce concept maps showing clusters of prioritized activities. Results: One hundred thirteen unique ideas/activities were generated, rated and sorted. Eight clusters were identified (from highest to lowest importance): hazard detection and safety outside; social interactions; navigation; near reading; selfcare and safety at home; distance spotting; searching around the home; and cooking and cleaning. Conclusions: The conceptual framework and low luminance ADLs identified (the most important being hazard detection and safety outside, and social interactions) provide a basis for developing a performance-based measure of low luminance visual function. Translational Relevance: A performance-based measure of low luminance vision-related ADLs is required for comprehensively and objectively assessing efficacy of eye treatments and low vision rehabilitation outcomes in adults with vision impairment.

Knowledge Assessment on Cortical Visual Impairment Among Ophthalmologists in Nepal.

INTRODUCTION: Cortical visual impairment (CVI) in children is a retro chiasmal visual tract disorder where there is with an impairment in the visual acuity and/or functionality of vision-guided task, including motor planning in the presence of normal ocular findings or minimal ocular morbidity. The study was conducted to assess the knowledge about CVI among ophthalmologists practicing in Nepal. MATERIALS AND METHODS: This was a cross sectional study. Data collection was done by administering a preformed, validated questionnaire that was sent via email to all the ophthalmologists registered under the Nepal Ophthalmic Society. The email mentioned the aim of the study along with the questionnaire. RESULTS: A total of 146 (37.82%) ophthalmologists responded to the questionnaire. Forty four percent of the participants were general ophthalmologists, 28% were pediatric ophthalmologists and 67% were ophthalmologists from other subspecialty. The median age of participants was 37.6 years. Most of the ophthalmologist had a good knowledge about the cause, common risk factors, clinical risk factors, management and prognosis of CVI. However only 29.5% of participants were aware of the investigation of choice for diagnosing CVI and 31.7% were aware of the leading causes of visual impairment in the developed countries. The study also established that the knowledge score was higher in pediatric ophthalmologists than the general ophthalmologist and ophthalmologists from other specialties. CONCLUSION: Most of the ophthalmologists had a good knowledge about the cause, common risk factors, clinical features, management and prognosis of CVI. However only a limited number of participants were aware of the investigation of choice for diagnosing CVI and the leading causes of visual impairment in the developed countries. Majority of the participants rarely examined patients with CVI which does not correlate with the high prevalence of perinatal hypoxia, the commonest cause of CVI, in our country.