Opinions of Special Education Teachers Working in Guidance and Research Centers on Functional Vision Assessment of Individuals with Low Vision

Principles of modern low vision rehabilitation

Infantile Nystagmus Syndrome (INS) is an ocular motor system dysfunction characterized by the rhythmic to-and-fro oscillations of the eyes. Traditionally, the assessment of INS visual function solely focused on null- or primary-position visual acuity. Our purpose is to use the past four decades of INS research to introduce a more complete assessment of visual function in patients with INS. All eye-movement data were obtained using high-speed digital video, infrared reflection, or scleral search coil systems. We have introduced four important aspects of a more complete INS visual function assessment: the eXpanded Nystagmus Acuity Function and visual acuity measurements in primary position; broadness of the eXpanded Nystagmus Acuity Function peak and high-acuity field; target acquisition time; and gaze-maintenance capability. Visual function in patients with INS is multifactorial and the simple assessment of primary position visual acuity is both inadequate and may not be the most important characteristic in overall visual function. A more complete visual function assessment should also include primary and lateral gaze eye-movement and visual acuity examinations, target acquisition time and gaze holding.

Aim: To investigate the influence of nystagmus on visual and social function and determine if parents are able to assess visual and social function in children with nystagmus. Method: A...

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A avaliação da visão funcional é um importante recurso para oferecer informações sobre a condição visual das crianças com múltipla deficiência, tendo em vista que grande parte desse público não recebe diagnóstico visual em tempo oportuno devido às dificuldades enfrentadas para a realização da avaliação oftalmológica. A presente pesquisa teve como objetivo avaliar a visão funcional de crianças com deficiência visual associada à múltipla deficiência, por meio do método de observação do comportamento e do teste Lea Gratings. Foi realizado um estudo de caso múltiplo com abordagem qualitativa, com cinco crianças que apresentavam deficiência visual associada à múltipla deficiência. Para a coleta de dados, foi realizada entrevista com os responsáveis e com os professores e avaliada a visão funcional das crianças participantes. Na avaliação da visão funcional constatou-se que todas as crianças apresentavam valores de acuidade de grades binocular bem abaixo dos valores padrões estabelecidos pela literatura, entretanto, possuíam visão funcional útil para o desempenho de tarefas cotidianas e escolares. Foi elaborado um instrumento denominado “suporte informacional”, que foi entregue aos participantes após o término da pesquisa, com dados sobre o resultado da avaliação da visão funcional das crianças, bem como informações sobre a visão, deficiência visual associada à múltipla deficiência e avaliação da visão funcional. O estudo demonstrou que a avaliação da visão funcional foi relevante para subsidiar a proposição de orientações adequadas para o desenvolvimento das ações dos responsáveis e das práticas pedagógicas dos professores com os alunos que participaram da pesquisa.

The Assessment of Visual Function and Functional Vision

The use of functional vision by school-age students who have visual impairments, including those with additional disabilities, is typically reported by teachers of students with visual impairments. Functional vision assessments determine how well student uses his or her vision to perform tasks throughout school day. The information that is gathered during functional vision assessment is summarized and used to determine an appropriate initial educational intervention or to modify an intervention on basis of changes in student's use of vision (Lueck, 2004). Functional vision assessments are mandated by Individuals with Disabilities Education Improvement Act of 2004. Before recommendations, such as specialized materials, methods, technology, lighting, seating, or additional support services, can be made, teacher of students with visual impairments must consider all components of visual functioning. Appropriate recommendations for intervention are based on an analysis of appearance of eyes, ocular abilities, visual fields, color vision, visual perceptual tasks, near vision, intermediate vision, distance vision, and orientation and mobility (OM D'Andrea & Farrenkopf, 2000; Erin & Paul, 1996; Lueck, 2004). There is no one correct way to assess functional vision (Bishop, 2004). The assessment materials and methods that are used depend on such factors as age of student, presence of additional medical or disabling conditions, amount of available time to conduct assessment, and environment. Some teachers use one or more of myriad assessment protocols that are available; some use forms they have developed, and some use combination of protocols. Selected commercially available tools are designed for students who are young or developmentally delayed; others are designed for young academic students, and yet others are designed for academic students who are older. Since functional vision assessments are not standardized, nor can they be, literature indicates that professionals use existing tools or their own (checklist) forms and (narrative) reports (or both), either singly or in combination (Bishop, 2004; Erin & Paul, 1996; Miller, 1999). Miller (1999, p. 2) stated that the [functional vision assessment] report is critical for ensuring coordination and consistency in educational programming and should be widely shared. She noted that many forms are available, and depending on age of student, makes sense that format and emphasis will differ by child (p. 2). However, she continued, with a wide variety of styles and methods for testing and reporting (p. 2), and depending on developmental level of student, there is no uniformity in how components of visual functioning are addressed, and there is no guarantee that all components will be addressed. Although there is no literature to confirm this finding, informal comments by district and agency supervisors and coordinators of university-based personnel preparation programs support notion that without guidance, components of visual functioning (such as specific distances from which an object is seen and size of an object that is seen at specific distance) are often not reported or are reported without specific information. Although it is important to capture uniqueness of each student's visual functioning, it is equally important to ensure that all components of visual functioning are addressed. …

Background: The study aimed to assess the vision improvement with low vision aids (LVA) and functional vision among children learning in schools for the blind in North-East India. Material and methods: 515 students from 17 blind schools of North-East India were recruited. The comprehensive ocular examination, functional vision assessment, and vision assessment using LVA were carried out for all the subjects after determining the magnification required for each subject. Results: Of 515 children, 124 required LVA. Spectacle magnifiers were the most preferred (73 students, 58.87%), followed by magnifiers (50 students, 40.32%). A statistically significant improvement in the mean visual acuity was noted after the use of LVA (p < 0.001). Conclusion: A detailed assessment of low vision prior to admission to schools should be made mandatory in blind schools. These schools would be able to cater to really blind children, while children with low vision could attend regular schools.

Assessment of visual processing disorders and their effect on children’s needs for special education is built on observations by parents, teachers and therapists of student’s strengths and problems. Visual problems at school should guide the medical specialists, psychologists and optometrists in assessment of visual functions. Ophthalmologists’ and optometrists’ work in assessments of binocularity, strabismus, oculomotor functions and accommodation is now developing; spectacles to correct refractive errors can be fitted in comfortable frames, training of visual functions is included in rehabilitation and reported to schools. Interdisciplinary collaboration between these large groups of educational and medical specialists should be developed further.

Introduction: This study analyzed 39 data collection tools used by teachers of students with visual impairments when completing functional vision assessments (FVAs). Methods: In 2017, teachers of students with visual impairments submitted data collection tools used in the FVA process. These tools were then compared with the 23 FVA components suggested by two established resources, Erin and Paul and D’Andrea and Farrenkopf. Results: The most commonly assessed skills and abilities were near visual acuity, distance visual acuity, and color perception. Only five of the submitted data collection tools contained at least 80% of the FVA components identified by the established resources. Fewer than 25% of the tools incorporated an orientation and mobility (O&M) screening. Discussion: There was considerable variation in the background information, medical data, and visual skills information that was collected. Variability in the data collected during the FVA process may impact a teacher’s recommendations, including referrals for specialized evaluations such as O&M and clinical low vision evaluations. Implications for practitioners: Since FVA reports are used by Individualized Education Program teams, it is essential that data collection tools used during the assessment process are complete and address key areas such as near visual acuity and color perception. Teachers should carefully review their tools to determine whether the data collected are sufficient to make informed recommendations regarding accommodations, goals, and referrals. If the data collected are not sufficient, then the tools should be revised or additional data should be collected.

Measurements of visual and oculomotor functions are essential for providing tailored support to visually impaired children. In young or intellectually disabled children these measurements can be difficult or even impossible to perform. Recordings of orienting gaze in response to specific visual information, made with eye tracking, may offer a solution. The aim of this study was to observe and quantify eye tracking (ET)-based gaze responses to provide information about visual and oculomotor functioning, and to compare this information with standard visual function assessments (VFA). One hundred and twenty-six visually impaired children from 1-14years underwent a VFA. Next they underwent a remote ET test. Four aspects of oculomotor control (nystagmus, fixation, saccades, pursuit) and three visual functions (visual field, contrast, colour) were selected to compare both methods. Performance was assessed (1) during VFA using standard behavioural observation and test scores and (2) after ET by observing and scoring the eye movement recordings. Validity, in terms of agreement between results, was measured by correlation analyses. From the orienting gaze responses, quantitative parameters (gain, fixation duration and directional saccades) were calculated to characterize visual performance. Good agreement between the two test methods was found for observational assessment of oculomotor control and visual functions (correlations ranging from rs =0.39 to rs =0.69). The quantitative parameters of visual performance showed distinct results between children with and without specific functional impairments, both in children aged 1-6 and 7-14years. Eye tracking-based gaze recordings are a promising tool to assess oculomotor and visual performance in a communication-free manner. Calculating quantitative parameters from specific gaze responses could assist in the characterization of functional visual performance in children, independent of age. Gaze responses are a useful addition to standard VFA in clinical practice.

Introduction: Children with early brain damage or dysfunction are at risk of developing cerebral visual impairment (CVI), including visual processing dysfunctions (VPD), which currently remain largely undetected until school age. Our aim was to systematically screen for possible VPD in children born very or extremely preterm from 1 to 2 years corrected age (CA) and to evaluate the effectiveness of early referral.Method: We included N = 48 children born < 30 weeks from 1 year CA. They underwent a two-step VPD screening based on (1) neurological signs indicative of visual brain damage evaluated by neonatologists and/or pediatric neurologist and (2) a functional assessment of visual orienting functions (VOF) with an eye tracking-based test. If at least one of these assessments was abnormal for their age, the children were classified as a risk of VPD and referred to undergo conventional visual diagnostics: ophthalmic exam and visual function assessment (VFA). At 2 years CA, VOF screening was repeated and neurodevelopment was assessed.Results: 18 children (38%) were classified as at risk of VPD at 1 year CA. 7 children had abnormal neurological signs, 5 children had abnormal VOF, and 6 children had both. Subsequent ophthalmic exams (N = 14) showed severe hypermetropia in 21% and strabismus in 14%. VFA (N = 10) showed abnormal visual function and behavior in only 1 child. At 2 years CA, the total group showed an increase in abnormal VOF. Whereas the children at risk showed some normalization, the group without VPD risk at 1 year CA showed deterioration of VOF. Neurodevelopmental outcome did not clearly differ between risk groups.Conclusion: Our findings show a substantial risk of VPD during visual screening (in 38%) at 1 year CA, but relatively few deficits on subsequent conventional ophthalmic exams and VFA. The data suggest that most conventional visual diagnostic methods at this young age are not related to the established VPD risks. VOF assessment should be used complimentary to these methods. The fact that at 2 years CA the number of children with a VPD risk based on abnormal VOF increased argues for more extensive and continuous screening in risk groups, at least until school age.

ABSTRACTIntroduction: Retinitis pigmentosa (RP) is the most common form of inherited retinal degenerations with an estimated prevalence of 1 in 4,000 and more than 1 million individuals affected worldwide. With the introduction of the first retinal gene therapy in 2017, the importance of understanding the mechanisms of retinal degeneration and its natural progression has shifted from being of academic interest to being of pivotal for the development of new therapies.Areas covered: This review covers standard and innovative diagnostic techniques and complementary examinations needed for the evaluation and treatment of RP. It includes chapters on the assessment of visual function, retinal morphology, and genotyping.Expert opinion: Monitoring the progression of RP can best be achieved by combining assessments of both visual function and morphology. Visual acuity testing using ETDRS charts should be complemented by low-luminance visual acuity and color vision tests. Assessment of the visual field can also be useful in less advanced cases. In those with central RP involvement measuring retinal sensitivity using microperimetry is recommended. Retinal morphology is best assessed by OCT and autofluorescence. Genetic testing is pivotal as it contributes to the pathophysiological understanding and can guide clinical management as well as identify individuals that could benefit from retinal gene therapy.

The Functional Vision Assessment (AVIF-2 to 6 years)'s capacity to differentiate visual ability levels in children with low vision was analyzed. The AVIF-2 to 6 years was created at the Infantile Low Vision Sector from São Geraldo Hospital, Brazil. After a debate among professionals from different areas regarding the appropriateness of the test items, AVIF-2 to 6 years was applied to 40 children aged from 2 to 6 years; twenty children with low vision (Group 1) and twenty without it (Group 2) were assessed. Group 1 was recruited from the Infantile Low Vision Sector from São Geraldo Hospital. Group 2 comprised children from two different public day care centers and children were matched by age, gender and social level with group 1. Seven domains were studied: visual fixation, visual following, visual field confrontation, eye-hand coordination and surrounding locomotion, contrast vision and color vision discrimination. Group 1 children were submitted to a complete ophthalmologic exam and group 2 to ophthalmologic screening. Children with low vision and neurologic disease were excluded. Comparative analyzes were performed for both groups and for distinct subgroups classified by age (24 to 35 months, 36 to 59 months and 60 to 78 months) and by visual acuity subgroups (<1.0 logMAR and ≥1.0 logMAR). The scores at total AVIF-2 to 6 years and its domains were statistically significant (p<0.05), except for the contrast vision and color vision discrimination domains. The total AVIF- 2 to 6 years median was lower for group 1 at the three interval ages. AVIF- 2 to 6 years can discriminate different levels of functional vision of low vision children, however the authors emphasize that although the results are encouraging, further studies shall be done until the test is ready for clinical use.

AIMTo develop and test a practical visual function assessment for use in developing countries.METHODSUsing focus group discussions and interviews with eyecare workers and low vision specialists in Malawi, 13 questions...