The Second Version of the L. V. Prasad-Functional Vision Questionnaire

Quality of life, functioning and participation of children and adolescents with visual impairment: A scoping review

BACKGROUND

Vision has a key role in children's neuromotor, cognitive and social development. Children with visual impairment attain developmental milestones at later stages and are at higher risk of developing psychological disorders and social withdrawn.

AIMS

We performed a scoping review to summarize the mostly used instruments assessing the impact of visual impairment on quality of life, functioning and participation of children and adolescents. In addition, the main findings of the included studies are discussed.

METHODS AND PROCEDURES

We searched for papers assessing quality of life, functioning and participation of children and adolescents with visual impairment from 0 to 18 years old conducted between 2000 and 2023.

OUTCOMES AND RESULTS

In total, 69 studies met the inclusion criteria and were included in the review. Child self-report, caregivers-proxy and self-report questionnaires as well as interviews were used. The results showed that quality of life, functioning and participation are significantly reduced in children and adolescents with visual impairment, and that the impact depends on different factors (e.g., severity of the impairment, age).

CONCLUSIONS AND IMPLICATIONS

Considering the significant impact of visual impairment on quality of life, functioning and participation on this population, it is fundamental to develop integrated and multi-dimensional assessment programs that evaluate the impact of visual impairment on those dimensions considering different contexts of life (e.g., family, school, leisure time). WHAT THIS PAPER ADDS?: The present review aims to give an overview of what is known about the impact of visual impairment on quality of life, functioning and participation of children and adolescents. We assumed a biopsychosocial perspective which, in line with the definition of health by the International Classification of Functioning, Disability and Health (WHO, 2001), considered how body functions and structures, functioning, participation and environmental factors dynamically interact to define the health, or the disease, status of a person at a certain moment of life. We reported the most used instruments for the assessment of quality of life, participation, and functioning, with a specific interest on Patient-Reported Outcome Measures and self-report measures. By reporting the different instruments used, we gave a broad overview about the available tools that can be used in clinical as well as in research field to assess quality of life, functioning and participation in this population. Additionally, the review of the existing literature allowed us to demonstrate that those dimensions are negatively impacted by visual impairment and thus they should be considered in the assessment programs. Specifically, there is the need to provide more integrated assessment programs that investigate the impact of visual impairment on children and adolescents' social and emotional wellbeing, everyday functioning and social relationship, considering their subjective experience together with the one of caregivers, teachers, health care professionals, and other relevant adults involved in their life. Additionally, it is essential to plan and implement multidimensional assessment programs that consider how all areas of life are differently impacted by visual impairment.

Health-related quality of life measurements in children and adolescents with refractive errors: A scoping review

Background

Refractive errors, particularly myopia, are the leading visual disorders worldwide, significantly affecting the quality of life (QOL) even after correction. This scoping review focuses on health-related quality of life (HRQOL) measurements for children and adolescents with refractive errors.

Main text

We explored generic and disease-specific HRQOL tools, examining their content, psychometric properties, and the impact of various interventions on QOL. Two English databases-PubMed, Embase, and one Chinese database, CNKI, were searched for relevant studies published from January 2001 to October 2023. Inclusion criteria encompassed studies using standardized instruments to assess the QOL of children aged 0-18 with refractive errors. The review compares prevalent HRQOL measurements, analyzes children's refractive error assessments, and discusses intervention effects on patient QOL.

Conclusions

The study underlines the necessity of developing disease-specific QOL instruments for very young children and serves as a practical guide for researchers in this field. The findings advocate for a targeted approach in HRQOL assessment among the pediatric population, identifying critical gaps in current methodologies.

Systematic Review of Instruments for the Assessment of Patient-Reported Outcomes and Quality of Life in Patients with Childhood Glaucoma

TOPIC

To identify patient-reported outcome measures (PROMs) that have been used in children and adolescents with glaucoma and to evaluate their methodologic quality.

CLINICAL RELEVANCE

Childhood glaucoma impairs vision and quality of life (QoL) throughout all stages of life. Thus, a PROM needs to cover many different age groups and topics. Various instruments have been used to evaluate patient-reported outcomes (PROs) in patients with childhood glaucoma, however, it is unclear which PROM has the highest methodologic quality and complies best with the needs of patients with childhood glaucoma.

METHODS

A systematic literature review was performed searching MEDLINE (PubMed), the Cochrane Library, Web of Science, and PsycINFO (EBSCO). We included peer-reviewed full-text articles of the past 10 years in English, German, or Spanish language that reported PROMs in children with glaucoma. The study selection and methodologic quality assessment of the identified PROMs was performed by 2 independent reviewers using a 7-point checklist. The content was mapped onto the World Health Organization International Classification of Functioning, Disability and Health. The systematic review was prospectively registered in PROSPERO (ID CRD42022353936).

RESULTS

The search strategy retrieved 3295 matches. A total of 2901 studies were screened, and 11 relevant articles were identified using 10 different instruments. The instruments addressed functional visual ability, vision-related QoL, health-related QoL, and life satisfaction. Six instruments were applicable for the use in children. Seven of the questionnaires received the highest number of positive ratings (5/7). None of the instruments considered the views of patients with childhood glaucoma during their development.

CONCLUSION

This systematic review provides a descriptive catalog of vision-specific and generic health PRO instruments that have been used in childhood glaucoma cohorts. An instrument specifically developed for childhood glaucoma is lacking which might result in missing important factors, such as permanent treatment with eye drops, repeated surgeries, and heritability of the disease, when investigating the QoL in children with glaucoma.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Development and clinimetric assessment of a performance-based functional vision tool in visually impaired children

Objective

Appropriate functional vision is vital for the development of visually impaired (VI) children. However, the literature currently lacks a performance-based tool for assessing functional vision, unlike the existing self-reported tools. The objective of this study is to develop and conduct a clinimetric study on a Performance-Based Functional Vision Tool (PB-FVT) specifically designed for VI children aged 3-7 and 7-10 years old.

Methods

This methodological study was conducted to assess the clinimetric properties of the PB-FVT. The assessment included face validity (evaluated through cognitive interviews and an Impact Score >1.5), content validity (with criteria including content validity ratio >0.63, item content validity index >0.78, scale content validity index or average >0.8, and Kappa value >0.7), criterion validity (assessed through a concurrent test using visual acuity scores), construct validity (utilizing the known group method), relative reliability (measured by the intra-class correlation coefficient), absolute reliability (determined by the standard error of measurement and minimal detectable changes), interpretability, responsiveness, sensitivity, and specificity (analyzed via ROC curve analysis).

Results

The PB-FVT was developed with 32 items, divided into five components: activities of daily living, instrumental activities of daily living, education, play, and social interaction. The results indicate that the scale demonstrates suitability in terms of validity, reliability, and other measurement characteristics.

Conclusions

The valid and reliable PB-FVT may accurately assess the level of functional vision during early childhood, helping to prevent negative impacts on a child's overall development. By utilizing the PB-FVT, any functional vision impairments can be identified appropriately, enabling the planning and implementation of effective rehabilitation interventions.

Vision-related tasks in children with visual impairment: a multi-method study

Objective

Functional Vision (FV) is vital for the successful growth of children with visual impairment. However, tasks related to measuring FV have not been thoroughly studied for this population. To address this gap, this study seeks to establish a comprehensive set of vision-related tasks that consider both the difficulty levels of activities and the ages of children with visual impairment.

Methods

This study utilized a sequential multi-method design, including a scoping review, a qualitative content analysis, and a focus group. Firstly, a scoping review was conducted to identify vision-related tasks based on the literature. Then, to contextualize the vision-related tasks, a qualitative content analysis was carried out. Subsequently, a focus group was conducted to categorize the identified tasks based on their difficulty levels and the children's level of dependency. We utilized the directed content analysis method to analyze the data, using the occupational domain of the Occupational Therapy Practice Framework 4th edition (OTPF-4) as the primary framework.

Results

During the review phase, which included 22 studies, and the interview phase, which involved 16 participants, a total of 95 and 85 vision-related tasks were identified, respectively. These tasks were then categorized into 17 activities and five occupations, which included activities of daily living (ADL), instrumental activities of daily living (IADL), education, play, and participation in social activities. Among these occupations, ADL was the easiest, while participation in social activities was the most challenging. Finally, the tasks were arranged based on their difficulty level for children with visual impairment.

Conclusion

A comprehensive list of vision-related tasks has been developed based on the difficulty level of the tasks and the degree of dependency of children with visual impairment. This list can be used to develop standardized instruments for assessing FV in children with visual impairment.

Therapy with voretigene neparvovec. How to measure success?

Retinal gene supplementation therapy such as the first approved one, voretigene neparvovec, delivers a functioning copy of the missing gene enabling the protein transcription in retinal cells and restore visual functions. After gene supplementation for the genetic defect, a complex network of functional regeneration is the consequence, whereas the extent is very individualized. Diagnostic and functional testings that have been used routinely by ophthalmologists so far to define the correct diagnosis, cannot be applied in the new context of defining small, sometimes subtle changes in visual functions. New view on retinal diagnostics is needed to understand this processes that define safety and efficacy of the treatment. Not only does vision have many aspects that must be addressed by specific evaluations and imaging techniques, but objective readouts of local retinal function for rods and cones separately have been an unmet need until recently. A reliable test-retest variability is necessary in rare diseases such as inherited retinal dystrophies, because statistics are often not applicable due to a low number of participants. Methods for a reliable individual evaluation of the therapy success are needed. In this manuscript we present an elaboration on retinal diagnostics combining psychophysics (eg. full-field stimulus threshold or dark adapted perimetry) as well as objective measures for local retinal function (eg. photopic and scotopic chromatic pupil campimetry) and retinal imaging for a meaningful workflow to apply in evaluation of the individual success in patients receiving gene therapy for photoreceptor diseases.

Quality of life in children with glaucoma: a qualitative interview study in Australia

OBJECTIVE

Childhood glaucoma is a chronic vision-threatening condition that may significantly impact an individual's psychosocial well-being. There is a paucity of literature investigating the quality of life (QoL) in children with glaucoma. The aim of this study was to investigate and report on the QoL issues encountered by children with glaucoma.

DESIGN

This is a qualitative interview study. Data were collected through semistructured interviews. NVivo V.12 software (QSR International Pty Ltd, Melbourne, Australia) was used to analyse and code data to identify QoL themes. The prominence of QoL themes was determined by the number of children who raised issues connected to the corresponding theme.

SETTING

Interviews were conducted via telephone or videoconferencing between April 2020 and July 2021.

PARTICIPANTS

Eighteen children with glaucoma, aged 8-17 years, who resided in Australia, were recruited from the Australian and New Zealand Registry of Advanced Glaucoma.

RESULTS

Median child age was 12.1 years (IQR: 9.7-14.5 years) and 33% were female. Seven QoL themes were identified: 'coping', 'inconveniences' and 'emotional well-being' were more prominent themes than 'symptoms', 'ocular health concerns', 'social well-being' and 'autonomy'. Adaptive coping strategies included resilience throughout clinical examinations and establishing positive relationships with ophthalmologists. These minimised inconveniences related to clinic waiting times and pupillary dilatation. External to the clinical setting, children often dissociated from their glaucoma but struggled with glare symptoms and feeling misunderstood by fellow peers. Older children aged 13-17 years commonly disengaged from their glaucoma care and expressed an unwillingness to attend ophthalmic appointments. Older children further raised issues with career options, obtaining a driver's licence and family planning under the theme of autonomy.

CONCLUSIONS

The psychosocial impact of childhood glaucoma extends beyond the clinical environment and was minimised using coping strategies. Older children may require additional social and ophthalmic support as they transition into adulthood.

Development and Evaluation of the Quality of Life Scale for Children With Visual Impairments in China

BACKGROUND

Visual impairments related to non-correctable vision loss, including blindness and low vision, have been consistently shown to lower a person's health-related quality of life. This study assessed the reliability, validity, and discrimination of the Quality of Life Scale for Children with Visual Impairments (QOLS-CVI) in China.

METHODS

The Pediatric Quality of Life Inventory™ 4.0 and World Health Organization Quality of Life-Disability Scale for physical disability were selected to define conceptual frameworks and item libraries based on relevant existing studies. According to two rounds of expert consultations and group discussions, some items were modified, and the draft scale was developed. Two item selection processes based on classical test theory and item response theory were used to conduct a preliminary survey and a formal survey in special schools in Shanxi and Hebei Provinces. Finally, the reliability and validity of the quality of life scale for visually impaired children in China were verified.

RESULTS

The final QOLS-CVI consisted of 38 items, 10 subdomains, and 6 domains. Reliability was verified by Cronbach's alpha coefficient, split-half reliability, and test-retest reliability (Cronbach's alpha for the full scale, 0.841; split-half reliability, 0.629; and test-retest reliability, 0.888). The validity results showed that the multidimensional scale met expectations: exploratory factor analysis and confirmatory factor analysis indicated good fitting models for children with visual impairments.

CONCLUSIONS

The QOLS-CVI was determined to be reliable and valid and to have strong feasibility and effectiveness. This scale can be used as an evaluation tool to study the QOL and social-participation ability of children with visual impairments.

Quality of life and functional vision across pediatric eye conditions assessed using the PedEyeQ

PURPOSE

To evaluate eye-related quality of life (ER-QOL) and functional vision across a wide range of pediatric eye conditions, using the Pediatric Eye Questionnaires (PedEyeQ).

METHODS

A total of 1,037 children with an eye condition and 254 visually normal controls, across 0-4, 5-11, and 12-17 years age groups, completed the following questionnaires: Child PedEyeQ (Functional Vision, Bothered by Eyes/Vision, Social, Frustration/Worry domains), Proxy PedEyeQ (same domains plus Eye Care), and Parent PedEyeQ (Impact on Parent and Family, Worry about Child's Eye Condition, Worry about Child's Self-perception and Interactions, and Worry about Functional Vision domains). The primary eye condition was classified as amblyopia (n = 171), cataract (n = 99), cerebral visual impairment (CVI; n = 50), cornea (n = 20), eyelid (n = 35), glaucoma (n = 24), nystagmus (n = 57), orbital (n = 19), pupil/iris (n = 7), refractive error (n = 119), retina (n = 82), strabismus (n = 332), and uveitis (n = 22).

RESULTS

PedEyeQ domain scores (scaled 0-100) were significantly worse across eye conditions, compared with controls. Child PedEyeQ greatest differences were on the Bothered by Eyes/Vision domain (nystagmus 5-11 years, -26 points [95% CI, -39 to -12]; nystagmus 12-17 years, -45 [95% CI, -61 to -28]). Proxy PedEyeQ differences were greatest on Functional Vision (CVI 0-4 years, -45 [95% CI, -56 to -34]; CVI 5-11 years, -58 [95% CI, -72 to -43]; nystagmus 12-17 years, -50 [95% CI, -69 to -31]). Parent PedEyeQ differences were greatest on Worry about Child's Functional Vision (CVI 0-4 years, -64; 95% CI -77 to -50).

CONCLUSIONS

The PedEyeQ detects reduced ER-QOL and functional vision across pediatric eye conditions, and across age groups, indicating its utility for clinical practice and clinical trials.

A Patient-reported Outcome Measure of Functional Vision for Children and Young People Aged 8 to 18 Years With Visual Impairment

PURPOSE

To develop age-appropriate extensions of a patient-reported outcome measure for capturing the functional impact of visual impairment on daily activities of children and young people aged 8 up to 18 years.

DESIGN

Questionnaire development and validation study.

METHODS

Pediatric Ophthalmology departments at Great Ormond Street Hospital and Moorfields Eye Hospital, and, in the final study phase, 20 further UK hospitals. Children and young people (aged 6-19 years) with visual impairment (acuity of the logarithm of the minimum angle of resolution (LogMAR) worse than 0.50 in the better eye) due to any cause but without significant non-ophthalmic impairments. We used our prototype FVQ_CYP for 10-15 year olds as the foundation. Twenty-nine semi-structured interviews confirmed relevance of existing, and identified new, age-specific items. Twenty-eight cognitive interviews captured information regarding comprehensibility and format. The FVQ_Child (8-12 years) and FVQ_Young Person (13-18 years) were evaluated with a national sample of 113 children and 96 young people using Rasch analysis.

RESULTS

Issues emerging from interviews with children and young people were largely congruent with those elicited originally with 10-15 year olds. The 28-item FVQ_Child and 38-item FVQ_Young Person versions have goodness-of-fit statistics within the interval 0.5, 1.5 and person separation values of 5.87 and 6.09 respectively. Twenty-four overlapping "core" items enabled their calibration on the same measurement scale. Correlations with acuity (r = 0.47) demonstrated construct validity.

CONCLUSIONS

The FVQ_C and FVQ_Young Person are robust age-appropriate versions of the FVQ_CYP which can be used cross-sectionally or sequentially/longitudinally across the age range of 8 up to 18 years in clinical practice and research.

Harmonization of Outcomes and Vision Endpoints in Vision Restoration Trials: Recommendations from the International HOVER Taskforce

Translational research in vision prosthetics, gene therapy, optogenetics, stem cell and other forms of transplantation, and sensory substitution is creating new therapeutic options for patients with neural forms of blindness. The technical challenges faced by each of these disciplines differ considerably, but they all face the same challenge of how to assess vision in patients with ultra-low vision (ULV), who will be the earliest subjects to receive new therapies.

Historically, there were few tests to assess vision in ULV patients. In the 1990s, the field of visual prosthetics expanded rapidly, and this activity led to a heightened need to develop better tests to quantify end points for clinical studies. Each group tended to develop novel tests, which made it difficult to compare outcomes across groups. The common lack of validation of the tests and the variable use of controls added to the challenge of interpreting the outcomes of these clinical studies.

In 2014, at the bi-annual International “Eye and the Chip” meeting of experts in the field of visual prosthetics, a group of interested leaders agreed to work cooperatively to develop the International Harmonization of Outcomes and Vision Endpoints in Vision Restoration Trials (HOVER) Taskforce. Under this banner, more than 80 specialists across seven topic areas joined an effort to formulate guidelines for performing and reporting psychophysical tests in humans who participate in clinical trials for visual restoration. This document provides the complete version of the consensus opinions from the HOVER taskforce, which, together with its rules of governance, will be posted on the website of the Henry Ford Department of Ophthalmology (www.artificialvision.org).

Research groups or companies that choose to follow these guidelines are encouraged to include a specific statement to that effect in their communications to the public. The Executive Committee of the HOVER Taskforce will maintain a list of all human psychophysical research in the relevant fields of research on the same website to provide an overview of methods and outcomes of all clinical work being performed in an attempt to restore vision to the blind. This website will also specify which scientific publications contain the statement of certification. The website will be updated every 2 years and continue to exist as a living document of worldwide efforts to restore vision to the blind.

The HOVER consensus document has been written by over 80 of the world's experts in vision restoration and low vision and provides recommendations on the measurement and reporting of patient outcomes in vision restoration trials.

Functional Vision Analysis in Patients With CHARGE Syndrome

PURPOSE

To evaluate functional vision in patients with CHARGE syndrome (coloboma, heart defects, atresia of the choanae, retardation of growth and development, genital and urinary anomalies, and ear anomalies) by using a new questionnaire entitled VISIOCHARGE.

METHODS

Ophthalmological data including fundus description and visual acuity, when available, were extracted from the charts of 83 patients with CHARGE syndrome, and the VISIOCHARGE questionnaire was prospectively mailed to 55 of those patients. The answers from the 36 responders (18 males) allowed for the calculation of three scores that assessed distance vision, near vision, and overall ability scores.

RESULTS

Visual acuity measurements were extracted from the charts of 20 of the 36 patients. The mean visual acuity was 20/50. The mean distance vision score of 0.62 ± 0.30 and near vision score of 0.78 ± 0.23 were correlated with visual acuity in the 20 patients (ρ = 0.64, P = .002 and ρ = 0.61, P = .005, respectively) and were associated with the severity of colobomatous malformation (P = .049 and P = .008, respectively). Severity of the ocular malformation was not associated with the overall ability score (P = .64).

CONCLUSIONS

The VISIOCHARGE questionnaire is feasible for patients with CHARGE syndrome and may help in the assessment of visual function. The mean visual acuity and answers to the VISIOCHARGE questionnaire showed relatively good visual skills in patients with CHARGE syndrome in everyday life, even in those with bilateral colobomas, which contrasts with the pessimistic conclusions usually resulting from the initial fundus examination. [J Pediatr Ophthalmol Strabismus. 2020;57(2):120-128.].

Beyond Intraocular Pressure: Visual Functioning and Quality of Life in Primary Congenital Glaucoma and Secondary Childhood Glaucoma

PURPOSE

To compare the visual functioning (VF) and vision-related QoL (VRQoL) of children 8-18 years old treated for primary congenital glaucoma (PCG) and secondary childhood glaucoma.

DESIGN

Cross-sectional study.

METHODS

A total of 309 children 8-18 years old treated for PCG and secondary childhood glaucoma between 2000 and 2010 by a single pediatric glaucoma specialist were prospectively enrolled at LV Prasad Eye Institute, Hyderabad, India. Children completed 2 questionnaires, the LV Prasad Functional Vision Questionnaire-II (LVP-FVQ-II), and the Impact of Vision Impairment-Children (IVI-C) questionnaire. Rasch-calibrated scores from both these questionnaires were used to compare the VF and VFQoL between the 2 groups.

RESULTS

Mean ages of the children were 12.2 and 12.6 years in the PCG (53%, median age at diagnosis = 5 months) and secondary glaucoma groups (47%, median age at diagnosis = 3 years), respectively. A majority (80%) of children had bilateral glaucoma and underwent filtering surgery (83%). Mean better eye logMAR visual acuity (VA) was comparable between PCG and secondary childhood glaucoma groups (0.49 vs 0.52, respectively; P = 0.59). Children with PCG reported significantly better VF and VRQoL than secondary childhood glaucoma patients. Unadjusted and adjusted childhood glaucoma group comparisons revealed secondary childhood glaucoma to be associated with worse VF and VRQoL compared to PCG (difference for VF, -0.83; 95% confidence interval [CI], -1.34 to 0.31; P = 0.002; 0.39; 95% CI, 0.16-0.62; P = 0.001 for VRQoL).

CONCLUSIONS

Results show that children with treated PCG experience significantly better VF and VRQoL than those with secondary childhood glaucoma, despite comparable VA and IOP.

Cross-cultural validation of the Functional Vision Questionnaire for Children and Young People (FVQ_CYP) with visual impairment in the Dutch population: challenges and opportunities

Background

To assess cross-cultural validity between Dutch and English versions of the FVQ_CYP, a patient-reported outcome measure developed in the United Kingdom (UK) for children and adolescents with (severe) visual impairment or blindness (VI for brevity) to measure functional vision.

Methods

The 36-item FVQ_CYP was translated and adapted into Dutch using standard guidelines. The questionnaire was administered to Dutch children and adolescents aged 7–17 years (N = 253) with impaired vision (no restrictions regarding acuity). Data were compared to existing UK data of children and adolescents aged 10–15 years (N = 91) with VI (acuity LogMar worse than 0.48). As with the original UK FVQ_CYP validation, a rating scale model (RSM) was applied to the Dutch data.

Results

Minor adaptations were needed in translation-rounds. Significant differences in item responses were found between the Dutch and UK data. Item response theory assumptions were met, but fit to the RSM was unsatisfactory. Therefore, psychometric properties of the Dutch FVQ_CYP were analysed irrespective of the original model and criteria used. A graded response model led to the removal of 12 items due to missing data, low information, overlapping content and limited relevance to Dutch children. Fit indices for the remaining 24 items were adequate.

Conclusions

Differences in population characteristics, distribution of responses, non-invariance at the model level and small sample sizes challenged the cross-cultural validation process. However, the Dutch adapted FVQ_CYP showed high measurement precision and broad coverage of items measuring children’s functional vision. The underlying reasons for differences between countries in instrument performance are discussed with implications for future studies.

Randomized Trial of Tablet Computers for Education and Learning in Children and Young People with Low Vision

SIGNIFICANCE

Mobile devices such as tablet computers have become widely available as mainstream devices and are also used in some schools, but there is an absence of robust information regarding the efficacy of any optical/electronic low vision device or tablet computer in supporting education of young people with low vision.

PURPOSE

A randomized controlled trial (RCT) is needed to measure the impact of tablet computers on education, specifically on independent access to educational material, in children and young people with low vision. We conducted a pilot RCT to determine the feasibility of conducting a full-scale trial.

METHODS

This was a randomized multicenter pilot trial across two sites in the United Kingdom and one site in India. Forty children and young people aged 10 to 18 years with low vision (best-corrected visual acuity for distance between <20/60 [0.48 logMAR] and 20/400 [1.30 logMAR] in the better eye) in the United Kingdom (n = 20) and India (n = 20) were randomized to two parallel arms, with a 1:1 allocation ratio, to control (n = 20) or intervention (n = 20). Control group participants received standard low vision care. The intervention group received a tablet computer (iPad) with low vision applications and instruction in its use, including accessibility features. Four primary outcomes included (1) 6-month recruitment rate, (2) retention of participants for 3 months, (3) acceptance/usage of device, and (4) accessibility of device.

RESULTS

Nineteen participants (95%) enrolled within 6 months in the United Kingdom, and 20 participants (100%), in India. Retention at 3 months was 85% (n = 17) in the United Kingdom and 95% (n = 19) in India. More than one half of participants reported using a tablet computer at school at least once every day. The majority (90%) found it easily accessible.

CONCLUSIONS

This study demonstrated that it is feasible to recruit children and young people with low vision into an international multicenter RCT of electronic assistive technology. Regardless of geographical location, children and young people with low vision reported using tablet computers at least once a day at school and accessed them easily.

Psychometric evaluation of a new proxy-instrument to assess participation in children aged 3-6 years with visual impairment: PAI-CY 3-6

Purpose

The Participation and Activity Inventory for Children and Youth 3–6 years (PAI‐CY 3‐6) was recently developed to assess the participation needs of children with visual impairment (VI) by means of parent‐proxy report. This study reports on its psychometric properties.

Methods

Parents of children aged 3–6 years registered at two low vision rehabilitation centers in the Netherlands were invited to participate and completed the 52‐item PAI‐CY. Satisfaction with the PAI‐CY 3‐6 was determined using an evaluation form. Basic item analyses was conducted, after which an item response theory (IRT) model (i.e. the graded response model, GRM) was fitted. Deletion of items was informed by results of item analyses, fulfillment of IRT assumptions, differential item functioning, fit to the GRM and item information content. Face and content validity were considered; professionals from low vision rehabilitation centers were asked for their opinion in the item deletion process. After obtaining a satisfactory set of items, known‐group validity, concurrent validity and test‐retest reliability were also investigated.

Results

Data of 237 parents were included in the analyses. Various aspects of the PAI‐CY 3‐6 were perceived as neutral to positive by over 85% of the respondents. After removing 17 items, the remaining 35 items reflected satisfactory fit to the GRM. Known‐group validity was supported, since participants with more severe VI and comorbidity scored significantly worse than those with less severe VI and without comorbidity after correcting for potential confounders. Test‐retest reliability was adequate, and the PAI‐CY showed to have good concurrent validity. Feedback from professionals motivated the maintenance of 3 of the 17 deleted items, although not included in the scoring. Furthermore, two new items were added, resulting in a 40‐item instrument.

Conclusions

The PAI‐CY 3‐6 has sound psychometric properties and can now be used to assess the participation needs of children aged 3–6 years with VI by means of proxy. Implementation in routine low vision rehabilitation care enables further optimization and investigation of its acceptability and feasibility.

Patient-derived questionnaire items for patient-reported outcome measures in pediatric eye conditions

PURPOSE

To identify specific health-related quality of life (HRQOL) and functional vision concerns of children with eye conditions, and create comprehensive lists of potential questionnaire items as a first step in developing patient-reported outcome measures.

METHODS

Children experiencing a range of pediatric eye conditions, along with one of their parents, were interviewed to identify specific concerns. Transcribed interviews were reviewed, and specific HRQOL and functional vision concerns were coded independently by two reviewers. Coded concerns were reviewed to formulate questions to address specific child concerns (derived from child and parent interviews) and specific parent concerns. Questions were grouped into bins of like questions. Two comprehensive lists of questions were formulated, one addressing child-related concerns and one addressing parent-related concerns.

RESULTS

This study included 180 children and 328 parents. A total of 614 individual child questions were grouped into 36 bins (eg, appearance, coordination, glasses, learning), and 589 parent questions were formulated and grouped into 61 bins (eg, having to assist the child, worry about deterioration, time off work, safety).

CONCLUSIONS

Using rigorous methods based on individual interviews, we identified a comprehensive list of patient- and parent-derived questionnaire items that address functional vision and HRQOL concerns of children with eye conditions and of their parents. We plan to use this large pool of potential questionnaire items to develop a formal set of pediatric outcome measures, and this pool of questions may also be a resource for future research.

Development of the Ultra-Low Vision Visual Functioning Questionnaire (ULV-VFQ)

Purpose

To develop and psychometrically evaluate a visual functioning questionnaire (VFQ) in an ultra-low vision (ULV) population.

Methods

Questionnaire items, based on visual activities self-reported by a ULV population, were categorized by functional visual domain (e.g., mobility) and visual aspect (e.g., contrast) to ensure a representative distribution. In Round 1, an initial set of 149 items was generated and administered to 90 participants with ULV (visual acuity [VA] ≤ 20/500; mean [SD] age 61 [15] years), including six patients with a retinal implant. Psychometric properties were evaluated through Rasch analysis and a revised set (150 items) was administered to 80 participants in Round 2.

Results

In Round 1, the person measure distribution (range, 8.6 logits) was centered at −1.50 logits relative to the item measures. In Round 2, the person measure distribution (range, 9.5 logits) was centered at −0.86 relative to the item mean. The reliability index in both rounds was 0.97 for Items and 0.99 for Persons. Infit analysis showed four underfit items in Round 1, five underfit items in Round 2 with a z-score greater than 4 cutoff. Principal component analysis on the residuals found 69.9% explained variance; the largest component in the unexplained variance was less than 3%.

Conclusions

The ULV-VFQ, developed with content generated from a ULV population, showed excellent psychometric properties as well as superior measurement validity in a ULV population.

Translational Relevance

The ULV-VFQ, part of the Prosthetic Low Vision Rehabilitation (PLoVR) development program, is a new VFQ developed for assessment of functional vision in ULV populations.

One size doesn't fit all: time to revisit patient-reported outcome measures (PROMs) in paediatric ophthalmology?

The purpose of this article is to summarise methodological challenges and opportunities in the development and application of patient reported outcome measures (PROMs) for the rare and complex population of children with visually impairing disorders. Following a literature review on development and application of PROMs in children in general, including those with disabilities and or/chronic condition, we identified and discuss here 5 key issues that are specific to children with visual impairment: (1) the conflation between theoretically distinct vision-related constructs and outcomes, (2) the importance of developmentally appropriate approaches to design and application of PROMs, (3) feasibility of standard questionnaire formats and administration for children with different levels of visual impairment, (4) feasibility and nature of self-reporting by visually impaired children, and (5) epidemiological, statistical and ethical considerations. There is an established need for vision-specific age-appropriate PROMs for use in paediatric ophthalmology, but there are significant practical and methodological challenges in developing and applying appropriate measures. Further understanding of the characteristics and needs of visually impaired children as questionnaire respondents is necessary for development of quality PROMs and their meaningful application in clinical practice and research.

Comparison of Rating Scales in the Development of Patient-Reported Outcome Measures for Children with Eye Disorders

BACKGROUND

A rating scale is a critical component of patient-reported outcome instrument design, but the optimal rating scale format for pediatric use has not been investigated. We compared rating scale performance when administering potential questionnaire items to children with eye disorders and their parents.

METHODS

Three commonly used rating scales were evaluated: frequency (never, sometimes, often, always), severity (not at all, a little, some, a lot), and difficulty (not difficult, a little difficult, difficult, very difficult). Ten patient-derived items were formatted for each rating scale, and rating scale testing order was randomized. Both child and parent were asked to comment on any problems with, or a preference for, a particular scale. Any confusion about options or inability to answer was recorded.

RESULTS

Twenty-one children, aged 5-17 years, with strabismus, amblyopia, or refractive error were recruited, each with one of their parents. Of the first 10 children, 4 (40%) had problems using the difficulty scale, compared with 1 (10%) using frequency, and none using severity. The difficulty scale was modified, replacing the word "difficult" with "hard." Eleven additional children (plus parents) then completed all 3 questionnaires. No children had problems using any scale. Four (36%) parents had problems using the difficulty ("hard") scale and 1 (9%) with frequency. Regarding preference, 6 (55%) of 11 children and 5 (50%) of 10 parents preferred using the frequency scale.

CONCLUSIONS

Children and parents found the frequency scale and question format to be the most easily understood. Children and parents also expressed preference for the frequency scale, compared with the difficulty and severity scales. We recommend frequency rating scales for patient-reported outcome measures in pediatric populations.

Measuring coping in parents of children with disabilities: a rasch model approach

Background

Parents of a child with disability must cope with greater demands than those living with a healthy child. Coping refers to a person’s cognitive or behavioral efforts to manage the demands of a stressful situation. The Coping Health Inventory for Parents (CHIP) is a well-recognized measure of coping among parents of chronically ill children and assesses different coping patterns using its three subscales. The purpose of this study was to provide further insights into the psychometric properties of the CHIP subscales in a sample of parents of children with disabilities.

Methods

In this cross-sectional study, 220 parents (mean age, 33.4 years; 85% mothers) caring for a child with disability enrolled in special schools as well as in mainstream schools completed the 45-item CHIP. Rasch analysis was applied to the CHIP data and the psychometric performance of each of the three subscales was tested. Subscale revision was performed in the context of Rasch analysis statistics.

Results

Response categories were not used as intended, necessitating combining categories, thereby reducing the number from 4 to 3. The subscale – ‘maintaining social support’ satisfied all the Rasch model expectations. Four item misfit the Rasch model in the subscale –maintaining family integration’, but their deletion resulted in a 15-item scale with items that fit the Rasch model well. The remaining subscale – ‘understanding the healthcare situation’ lacked adequate measurement precision (<2.0 logits).

Conclusions

The current Rasch analyses add to the evidence of measurement properties of the CHIP and show that the two of its subscales (one original and the other revised) have good psychometric properties and work well to measure coping patterns in parents of children with disabilities. However the third subscale is limited by its inadequate measurement precision and requires more items.

Quality assessment of ophthalmic questionnaires: review and recommendations

PURPOSE

The aim of this article was to systematically review all the available ophthalmic patient-reported outcome (PRO) instruments (questionnaires) that demonstrated interval measurement properties to identify the instruments with the highest psychometric quality for use in different eye diseases and conditions.

METHODS

An extensive literature review was carried out to identify all existing ophthalmic PRO instruments. Instruments were then excluded if they did not have demonstrable interval measurement properties; the remaining instruments were reviewed. The quality of the following psychometric properties was assessed: content development (initial item development process), performance of the response scale, dimensionality (whether the instrument measures a single construct), measurement precision, validity (convergent, concurrent, discriminant, and known groups), reliability (test-retest), targeting (whether the items are appropriate [e.g., difficulty level] for the population), differential item functioning (whether subgroups of people respond differently to an item), and responsiveness.

RESULTS

The search identified 48 PRO instruments that demonstrated interval measurement properties, and these were relevant to nine applications: glaucoma, dry eye, refractive errors, cataract, amblyopia and strabismus, macular diseases, adult low vision, children low vision, and others. These instruments were evaluated against the psychometric property quality criteria and were rated for quality based on the number of criteria met.

CONCLUSIONS

This review provides a descriptive catalog of ophthalmic PRO instruments to inform researchers and clinicians on the choice of the highest-quality PRO instrument suitable for their purpose.

Rasch analysis of Impact of Vision Impairment for Children questionnaire

PURPOSE

To validate the Indian-translated Impact of Vision Impairment for Children (IVI_C), a vision-related quality of life (VRQoL) instrument, and to investigate the effect of sociodemographic and ocular characteristics on VRQoL.

METHODS

The 24-item IVI_C was administered face to face to 221 children with vision impairment (VI) (mean age, 12.6 years; male, 68%) referred to the Vision Rehabilitation Centres. Rasch analysis was used to investigate the IVI_C for key indices such as measurement precision as measured by person separation (minimum recommended value, 2.0), unidimensionality (i.e., whether all the items contribute toward measurement of a single underlying construct as assessed by item fit and principal component analysis of residuals), targeting of items to participants' VRQoL (i.e., matching of item difficulty to participant ability; ideal targeting, <1.0 logits). Univariate analysis was performed to determine if the person scores of IVI_C were significantly different across participant subgroups stratified by sociodemographic and ocular characteristics, including the severity of VI.

RESULTS

The IVI_C showed misfit to the model and lacked unidimensionality. Principal component analysis confirmed the presence of an additional construct, mobility, but it did not possess adequate person separation when assessed individually. Deleting the mobility-related items restored unidimensionality, but additional items misfit, necessitating item reduction. Finally, a 17-item IVI_C possessed good measurement precision (person separation, 2.04), was unidimensional (albeit not purely), and consisted of items that fit the Rasch model and were well targeted to the participants' VRQoL (targeting 0.76 logits). There was no statistically significant difference in the VRQoL across subgroups stratified by age, sex, type of school, cause of VI, duration of vision loss, and severity of VI (p > 0.05 for all).

CONCLUSIONS

The revised 17-item IVI_C is shorter and has better psychometric properties than the original version in school-aged children with VI in India, and the responses are unrelated to sociodemographic and clinical variables. Although it has the potential for use in cross-sectional and outcomes research in children with VI, caution should be exercised while interpreting the 17-item IVI_C scores given the presence of slight multidimensionality.

Patient-reported outcome measures (PROMs) in paediatric ophthalmology: a systematic review

AIM

To identify patient-reported outcome measures (PROMs) specifically developed and used to assess the impact of ophthalmic disorders in children and to systematically assess their quality as a basis for recommendations about their use in clinical and research settings.

METHODS

A systematic review of the literature was performed in MEDLINE, EMBASE, PsychINFO, CINAHL and AMED, supplemented by a grey literature search. Papers reporting development and validation of questionnaire instruments for assessing patient-reported outcomes of an ophthalmic disorder in patients aged 2-18 years were included. Quality was assessed by examining the purpose and psychometric properties of the instruments. Strengths and limitations were summarised with recommendations regarding use.

RESULTS

Search identified 17 instruments. Of these, 11 were condition-specific and six were intended for a broader population of children and young people with visual impairment regardless of the ophthalmic condition. Three were developed for use in a specific trial and two are still in development.

CONCLUSIONS

Paediatric ophthalmology PROM development and application is a developing field and new instruments are needed. There is scope for improvement in this area through (a) clarity of definitions of the underlying constructs intended to be measured at the onset of development of new instruments, (b) application of child-centred approaches and (c) adherence to extant guidance and best practice in questionnaire instrument development.