Abstract
PURPOSE:
To assess the functional capabilities and performance in children with visual impairment who live in a developing country.
METHODS:
This was a case-control study, including binocular and monocular visually impaired children and non-visually disabled controls aged between 4 and 12 years. All participants underwent a basic ophthalmic exam and caregivers answered the Pediatric Evaluation of Disability Inventory (PEDI). The results were compared among the groups with ANOVA.
RESULTS:
The sample included 35 children with visual disability (21 binocular and 14 monocular) and 23 age-matched controls. The groups did not differ in age, gender, and ethnicity. For the functional skills scale, binocular impaired children had lower scores than children from the monocular group and controls in all three domains – self-care (59.6±33.0, P < 0.001), mobility (38.5±26.6, P < 0.001), and social function (61.0±28.2, P < 0.001). For the caregiver assistance scale, children from the binocular group presented lower scores in the self-care (64.7±29.6, P = 0.002), mobility (50.6±36.3, P < 0.001), and social function (65.9±33.4, P = 0.008) domains as compared to monocular and controls. Children with monocular visual disability presented very similar scores to controls (all P > 0.05).
CONCLUSION:
Children with binocular visual impairment presented some degree of difficulty with everyday functioning whereas monocular visual impairment did not cause any limitation in function.
Introduction
The basic or physical activities of daily living include all the skills required to manage a person’s basic physical needs, such as grooming or personal hygiene, dressing, toileting, transferring or ambulating, and eating [1]. Impaired physical function can develop as a result of a plethora of reasons – neurological, musculoskeletal, circulatory, or sensory (visual included) conditions; cognitive decline in dementia and aging; side effects of medications, and social isolation, to name a few [2–4]. The inability to accomplish essential activities of daily living not only leads to unsafe conditions but can negatively affect the quality of life [1]. In children, limitations in activities of daily living can impact active play, peer relationships, independence skills, and academic progress that may persist up to secondary school [5].
Humans make contact with the environment primarily through the visual system. Early inadequacy of the intersensorial coordination can delay the development of basic cognitive and motor skills; visual impairments presenting in early infancy can delay adequate development due to decreased awareness or interaction with the environment [6]. Children with visual impairment have a less harmonious development of motor skills experiencing delays in many aspects of motor development that influence the quality of activities related to mobility [6]. These include difficulty adopting the prone position, frequently skipping the crawling and creeping stages, and learning to walk only after age 2; problems with psychomotor activities, including hand-eye coordination, bilateral coordination, and motor planning; inability to perform many motor activities through sheer imitation; and increased anxiety when negotiating spaces [6].
The limitations that visual impairment imposes on to everyday functioning in children with low vision have not been extensively studied in developing countries where low income and privation of health insurance restricts access to the healthcare system and precludes early therapeutic intervention. Besides, some of these studies were biased by inappropriate inclusion criteria and a small sample size [7, 8]. Hence, the purpose of this study was to assess the functional capabilities and performance in visually impaired children who live in a developing country and to compare the level of difficulty between children with monocular impairment and those with binocular deficiency.
Methods
This was a case-control study that included children with visual disabilities presenting at the Pediatric Ophthalmology Service, Irmandade da Santa Casa de Misericordia de Sao Paulo, Sao Paulo, Brazil between June, 2019 and May, 2020. This is a large charity hospital located in a densely populated area in downtown Sao Paulo. All patients seen there do not have private medical insurance and their medical care is paid by the Unified Health System (SUS), Ministry of Health. The institution ethics committee approved the study proceedings which followed the tenets of the Declaration of Helsinki – and its late amendments – and the Resolution 466/12, National Council of Health, Ministry of Health, Brazil. Parents or legal guardians signed the informed consent. Prior to enrollment, all participants – children and their parents or legal guardians – were given details on the study purpose and procedures. An informed consent (and informed assent for the child older than 6 years) was signed and the confidentiality, the guarantee of the well-being, and integrity of the participants were reassured.
Participants and inclusion criteria
Children aged between 4 and 12 years with moderate or severe visual disability in at least one eye were invited to participate in the study. Patients were recruited via consecutive sampling. Mild visual impairment was defined as a child presenting distance visual acuity (VA) equal to or better than 20/70 (6/18) in one or both eyes; severe visual impairment as a presenting distance VA worse than 20/200 (6/60), and equal to or better than 20/400 (3/60) in one eye (monocular) or both eyes (binocular visual impairment) according to the International Statistical Classification of Diseases and Related Health Problems 11th Revision (ICD-10) version for 2018 [9]. Another age-matched group of children with no ocular diseases, except mild ametropias, VA of 20/25 or better on both eyes and normal stereopsis were included as controls. The control group was conveniently recruited among patients already scheduled for routine refractive errors examination or siblings of patients.
Procedures
After a brief medical history, all participants underwent an ophthalmic examination including measurement of the best-corrected VA using a Snellen chart at 20 feet (6 m), ocular motility assessment – cover test, ocular deviation by Hirschberg corneal reflex, and ocular movements –, biomicroscopy with the slit lamp (SL-2G slit lamp, Topcon Corporation, Tokyo, Japan), and dilated retina evaluation with the direct ophthalmoscope (Welch Allyn Inc., Skaneateles Falls, NY).
Assessment of daily functioning
The assessment of everyday functioning was completed with the Pediatric Evaluation of Disability Inventory (PEDI). This is a comprehensive clinical assessment that samples key functional capabilities and performance in children with disabilities between the ages of 6 months to 7½ years, although scaled scores can be used for children of all ages [10]. It was translated and validated into Brazilian-Portuguese (PEDI Brazilian version 1.0). The PEDI has been developed to measure functional performance and capability in three main scales: Functional Skills, Caregiver Assistance, and Modification. Each scale is divided into three domains: Self-Care, Mobility, and Social Function [11].
Each domain is comprised of several questions (items) within different content areas. The Self-Care domain includes activities of daily living. The Mobility domain includes floor mobility, simple transfers, and mobility in different environments. The Social Function domain concerns living with others in a community and interacting with family members. Content areas within this domain are functional communication, comprehension, and other cognitive skills.
Part I (Functional Skills scale) consists of 197 dichotomous items and is scored either ‘capable’ or ‘unable’. These items are divided into Self-Care domain (73 items measuring activities such as eating, grooming, dressing, and personal hygiene), Mobility domain (59 items covering transfers, for example, in and out of bed and bathtub, indoor and outdoor locomotion, and stairs), and the Social Function domain (65 items measuring communication, problem-solving, play with peers, and safety). Sum scores (raw scores) were obtained by adding the items within each domain and each content area. Part II (Caregiver Assistance scale) consists of 20 items (Self-Care, Mobility, and Social Function) scored in relation to a scale from independent (5) to total help (0), with specific scoring criteria for each level. Part III (Modification scale) is rated in relation to the same 20 items in part II but according to whether technical or environmental adaptations are used to enhance performance. Since no children had been trained previously with activities of daily living skills and did not use any equipment and modifications, the Modification scale was not used in this study.
The PEDI manual describes a normative standard score and a scaled score. The normative is a transformed score that depends on the child’s age. It is used to compare individual scores of children with those of the same age range to assess any deficit or delay in the development of functional status, in each content area, and its extension. The scaled score gives an indication of the functional performance independent of age and can be used to determine changes in functional status over a period of time.
Aggregate scores were defined as the sum of each domain. Scores were distributed from 0– 100, with higher scores representing greater functionality. The normative score was retrieved from a specific table provided by the PEDI developers in the Brazilian-Portuguese version for children up to 7.5 years of age [12]. The scaled scores were calculated for all participants in order to enable analysis of the whole sample. The questionnaire was administered by the authors as a structured parental-report, in-person interview to one of the parents or caregivers of all participants in an environment other than the ophthalmic exam room which usually took 45 to 60 minutes. The interviewer introduced themself and explained the study’s aim and procedures – at this time, the relationship with the study participants was initiated. Field notes were made during the interview, but no audio or visual recording was used to collect the data.
Statistical analysis
Data were plotted on an Excel spreadsheet (Microsoft Corp., Redmont, WA) and raw scores (summary scores) were calculated by adding the scorings within each domain. Categorical variables were presented as frequencies and continuous variables as mean±standard deviation. Visually impaired patients were stratified into either monocular or binocular groups whether only one or both eyes were affected, respectively. Snellen VA was converted to Logarithm of the Minimum Angle of Resolution (LogMAR) VA to facilitate statistical comparison. The MAR is the width of the stroke or one-fifth of the angular sub-tense of the optotype. VA values are presented in numerical format making data scoring and analysis easier than Snellen VA. This notation is advantageous, especially in research, since it allows scoring low VA accurately and including these data in the statistical analysis. Categorical variables (gender, ethnicity, and diagnosis) were compared among the groups using the Fisher exact test, and continuous variables (age, VA, and PEDI scores) were compared with the one-way ANOVA (analysis of variance) and the Tukey HSD (honestly significant difference) post-hoc test. Statistical calculations were completed with the OpenEpi (Open Source Epidemiologic Statistics for Public Health) software, version 3.01 (The OpenEpi Project, Atlanta, GA). The P value less than 0.05 was set as the level to reject the null hypothesis.
Results
The sample comprised 35 children with visual impairment (21 binocular and 14 monocular) and 23 controls. The groups did not differ in age, gender, and ethnic distribution. All participants older than 6 years of age were regularly attending elementary school. Both visually impaired and controls were similar in socioeconomic aspects: most families had no private medical insurance plan, the yearly income was less than USD 8,000 for all participants, and most parents (92%) had only a high school degree or less and as such they were representative of an average Brazilian family. Detailed information on visual acuity and clinical diagnosis is depicted on Table 1. Eight patients in the binocular group had albinism, and in the monocular group, most patients had strabismus and congenital cataract. Other less frequent diagnoses, not listed on Table 1, included Leber congenital amaurosis, aniridia, cone distrophy, iris coloboma, and retinal vasculitis. Age range data according to gender per group is presented on Table 2.
Patients demographic and clinical characteristics
Patients demographic and clinical characteristics
VA: visual acuity; logMAR: logarithm of the minimum angle of resolution.
Age distribution according to gender per group
Table 3 depicts the PEDI scaled scores for the binocular visual impairment, monocular visual impairment, and controls. In all three domains – Self-Care, Mobility, and Social Function – for Functional Skills scale, binocular impaired children had lower scores than children from the monocular impaired group and controls. For the Caregiver Assistance scale, children from the binocular impairment group scored lower in the three domains compared to children with monocular impairment and controls, except in the Social Function (when compared to controls, P = 0.054). Children with monocular visual disability presented very similar scores on all three domains for Functional Skills and Caregiver Assistance compared to controls. Bias corrected (Hedges’ g) effect sizes are presented in Table 4. A subanalysis of children younger than 7.5 years is depicted in Table 5. The scores differed for most domains between binoculars and both monoculars and controls but with less statistical significance. The difference between monoculars and controls was not statistically significant.
Pediatric Evaluation of Disability Inventory scale scores results
(a) Tukey HSD post-hoc between binocular and monocular. (b) Tukey HSD post-hoc between binocular and control. (c) Tukey HSD post-hoc between monocular and control.
Bias corrected (Hedges’ g) effect size of PEDI scores between patients with binocular and monocular visual impairment (a) and between binocular visual impairment patients and controls (b)
Pediatric Evaluation of Disability Inventory normative scores results for children up to 7.5 years of age
(a) Tukey HSD post-hoc between binocular and monocular. (b) Tukey HSD post-hoc between binocular and control. (c) Tukey HSD post-hoc between monocular and control.
The results of this study revealed that visually impaired children of both eyes do struggle with daily routine activities to some extent, and youths with only one functioning eye have a similar level of motor skills to a child with no visual disability. Health is often viewed as a multi-dimensional concept partly conceptualized independent from not being ill; particularly, young children perceive health as a multi-dimensional construct, largely related to being engaged, i.e., to be able to perform wanted activities and participate in a supportive every day context [7]. Visually impaired children have the same needs as healthy children. The understanding of their experiences of everyday life is essential to help develop strategies of inclusion in society, whether at home or at school, and to facilitate simple activities most children would take for granted.
The functional capabilities and performance in children with low vision have not been extensively studied. Salavati et al. adapted the Dutch version of PEDI and the Gross Motor Function Measure-88 (GMFM-88) for children with cerebral visual impairment and cerebral palsy [14, 15]. The summed scores of the first interview for Functional Skills (Self-Care 34±17.5, Mobility 31±18.5, and Social Function 37±14.0) and Caregiver Assistance (Self-Care 17±9.3, Mobility 15±12.2, and Social Function 12±4.7) domains were much lower compared to the results of our study [16]. The authors included patients with more severe functional capability whereas, in our study, patients only had visual impairment and no other condition affecting cerebral function, such as cerebral palsy. Mancini et al. compared the functioning of children with low vision and non-visually disabled children in two age groups, 2-y.o. and 6-y.o. The authors reported that 2-y.o. children with low vision – but not the 6-y.o. – had smaller skill repertoire in Self-Care and Mobility PEDI domains and needed more assistance from the caregiver [7]. The sample selection, however, was biased since participants were recruited from an Occupational Therapy (OT) clinic, and all of them had been trained previously with activities of daily living skills. In our study, no patient had any previous care with OT, and in the analysis, participants were not stratified by age groups. Malta et al. used the PEDI to evaluate a small cohort of Brazilian children with low vision [8]. The authors reported only scores of the Functional Skills scale as follows: Self-Care 63±7.3, Mobility 54±6.2, and Social Function 53±7.2. Those scores differ from what we found, especially for Mobility (38.5±26.6); however, the authors only included 10 children with low vision where the mean age was 6.6 years (vs. 9.0 in our study).
The Functional Skills section of the PEDI provides summary scores that reflect the child’s current repertoire of daily life skills in each of three domains [4]. In this study, participants with binocular visual impairment reported some difficulty in all of these domains. The Self-Care domain includes assessment of activities such as feeding, grooming, bathing, dressing upper and lower body, bladder management, bowel management, toileting, and independent routines. The item in which a higher proportion of parents of children with binocular visual impairment responded “unable” was the use of utensils for eating (37.5%). This observation has implications on the nourishment, health, and adequate growth of the child. The Mobility domain evaluates actions like tub, chair, and bed transfer, locomotion within a room and between rooms, locomotion outdoors, and stair-climbing ability. Locomotion outdoors – distance/speed was the item which most parents reported the child being unable (50%). The Social Function domain measures comprehension, expression, social interaction, and play with peers. The item self-protection was the one which most parents reported the child being unable to perform (87.5%). This item evaluates care displayed by the child when standing near a staircase, hot objects or sharp objects used primarily for cutting, and when crossing the street. Understanding these main difficulties can help healthcare providers to assist children with binocular visual impairment to address their needs.
The Caregiver Assistance section provides a summary of the extent to which the child’s overall performance of complex daily tasks such as getting dressed or moving around is supported by help from a caregiver [10]. In this study, parents of children with binocular visual disabilities realized their children needed support to get dressed and to move around.
This study has strong implications for children who live in a developing country. Brazil is currently rated as an upper-middle-income economy according to the World Bank rating, with many healthcare issues common to a developing country: privation of health insurance, insufficient household income, lack of access to credit, misperceptions of illness, and the effectiveness of care to name a few [17, 18]. The compromised functional capabilities and performance with daily routine activities caused by the visual impairment pose an additional challenge on these children and their families. These children demand more attention and extra-care both at school and at home. In many ways, that means more costs for education, and it can prevent one of the parents from having a secular job to help in the family financial gain – that is especially true in low-income families. For this reason, it would be fair for the parents to get financial support from the government. At the same time, the risk is the secondary benefits the impairment of the child means for some families because he or she becomes a source of income. This is an aspect that can be seen in daily clinical practice, at least in developing countries. This fact has psychological and social implications for the child because his/her subjectivity changes according to the place he/she has in the family.
On the other hand, children with only one impaired eye reported no difficulty with everyday activities, performing skills at a similar level to children from the control group. One common concern parents of visually disabled children have is whether their children can grow up as a typically developing child and become productive adults. Based on the results of this study, parents can be assured that their child has no limitation in the performance of daily activities and will likely reach adulthood without difficulty. In Brazil, we observe that parents of visually impaired children frequently look for opportunities to receive compensatory indemnity or social government benefits for the child or even for themselves. In this regard, the results of our study do not provide evidence to support eligibility for social security benefits since monocular impaired children did not have any limitation to justify such claims. Parents should be reassured their children can live a full life into adulthood.
This study has a few limitations. First, children with monocular disability had better VA, both in the better eye and the worse one. In fact, the better eye had VA inferior to the non-disabled controls, and the worse eye was better than the binocular group. Ideally, the monocular group should be comprised of patients with 20/20 (logMAR VA 0.0) in the better eye, just like the controls. However, the fact that the monocular group had on average a logMAR VA of 0.48 (Snellen VA 20/40) highlights that a person does not need to have 20/20 vision in order to function as someone with no visual impairment. Second, we have included participants up to 12 years of age, and the PEDI was initially developed for children between 6 months and 7½ years. However, scaled scores can be used for children of all ages since these are not adjusted by age. Besides, in case of functional delays, the questionnaire can also be used in the evaluation of older children [19]. Third, the sample comprised a heterogeneous group of children with different eye conditions some acquired, but most congenital diseases. Nevertheless, all of these eye conditions share the same end result – low vision and no other cognitive or motor disability – and the sample was small for a sub-analysis per disease. Last, the sample size was small, especially in the monocular group. However, the size was large enough to reveal a statistical difference of PEDI scores among the groups.
In conclusion, children with binocular visual impairment living in a middle-income country presented some degree of difficulty with everyday functioning, whereas monocular visual impairment did not cause any difficulties. The results of this study position children with a monocular disability and their families in a similar situation of non-visually impaired children, while also contributing to the rights of the visually impaired population. This issue should be addressed by local authorities in developing specific motor training programs and implementing strategies to help integrate these patients into society.
Conflicts of interest
The authors report no potential conflict of interest.
Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.