What Are Signs of Autism in a Baby Two Years Old Born Legally Blind

Introduction

The prevalence of childhood blindness varies according to socioeconomic status, and the majority of children with blindness worldwide live in the poorest countries of Africa and Asia. In very low-income countries with high mortality rates in children younger than 5 years, the prevalence may be as high as 1.5 per 1000 children, in contrast to high-income countries where the prevalence is five times less (Gilbert 2007). There are several unavoidable causes of childhood blindness in developed countries, such as genetic diseases and other prenatal disorders affecting the central nervous system (Ozturk et al. 2016). Retina is the most common anatomic site of involvement in childhood blindness worldwide, and retinopathy of prematurity (ROP), a perinatally acquired condition, is a significant cause of blindness globally (Gilbert 2008). The incidence of ROP has increased in the last decades in developed countries due to advances in neonatal care entailing increased survival rates of preterm born infants (Hellström et al. 2013; Zin & Gole 2013; Ozturk et al. 2016).

The three most prevalent causes of severe visual impairments and blindness in young children in the United States during recent years are cortical visual impairment (CVI), ROP and optic nerve hypoplasia (ONH) (Hatton et al. 2013). In Poland, the most common causes between the years 1974 and 2004 were optic nerve atrophy (ONA), ROP and high myopia, with an increasing incidence of ONA and decrease in ROP (Seroczyńska et al. 2007). A Norwegian study examining causes of visual impairment among Braille users born 1967–2007 identified the most frequent conditions as ROP, juvenile neuronal ceroid lipofuscinoses (JNCL), Leber congenital amaurosis (LCA), ONH and retinitis pigmentosa (RP) (Augestad et al. 2012).

The coexistence of visual impairment and additional developmental disorders is well known. In the US study referred to above, 65% of the children had developmental delays or additional disabilities (Hatton et al. 2013). In Sweden, almost two-thirds of all children with visual impairment have been reported to have intellectual disability (ID), motor impairment and/or hearing impairment (Blohmé et al. 2000). Neurodevelopmental disorders such as autism spectrum disorders (ASD) or attention-deficit/hyperactivity disorder (AD/HD) are not included in these numbers. Children with total blindness or light perception are at particular risk for developmental challenges (Hatton et al. 1997). For example, around 30% of completely blind children (regardless of aetiology) have been reported to have ASD (Cass et al. 1994; Hobson et al. 1997). In preterm children with blindness due to ROP, the number has been described to be even higher, with three quarters having major neurological impairment and nearly two-thirds having ASD (Ek et al. 1998; Jacobson et al. 1998). In a later Swedish population-based study of extremely preterm children, 75% had stage 3 ROP or worse, leading to severe visual impairment or blindness. Of these children, 76% also had other deficits such as hearing, cognitive, behavioural and/or motor dysfunction (Jacobson et al. 2009). Another visual condition that has been described to have a high co-occurrence with developmental disorders is ONH, a prenatal condition involving acquired or gene–environment interaction aetiologies. Bilateral ONH is an increasingly frequent cause of blindness (Borchert 2012), and developmental delays occur in the majority of these children (Garcia-Filion et al. 2008). Parr et al. (2010) reported that autism or autistic features occurred in 37% of children with severe or moderate visual impairment due to ONH. In 1997, bilateral ONH surpassed ROP as the leading cause of infant blindness in Sweden (Blohmé & Tornqvist 1997). Behavioural problems and autistic features are more frequent in children with bilateral compared to unilateral ONH (Teär Fahnehjelm et al. 2014), and the majority of children with blindness due to bilateral ONH have ASD, with or without ID (Ek et al. 2005).

Since 1990, Swedish children with visual impairments have been reported to a national register (Blohmé & Tornqvist 1997). During recent years, the coverage of this register has decreased and reliable statistics about the population has been increasingly difficult to retrieve. Since the statistics in Sweden needed to be supplemented, the aim of this study was to describe the population of children with congenital or infant bilateral blindness, concerning aspects such as causes of blindness, prevalence of additional developmental disorders/impairments and school placement. The research questions were as follows:

• What were the most common causes of blindness during the studied 21-year period?
• What was the prevalence of different developmental disorders?
• What was the prevalence of autism in specific aetiological subgroups?
• What are the implications for the further development of support to children with blindness?

Patients and Methods

This study had a retrospective population-based design, and all data were retrieved from medical, psychological and pedagogical records, as described below.

Participants

The study population comprised all children living in Sweden, with prenatal/perinatal or early infancy blindness, born between 1988 and 2008, who were known at Resource Centre Vision (RCV), the national resource centre for children with blindness and visual impairments, within the Swedish National Agency for Special Needs Education and Schools (SNASNE). Blindness was in this study defined as total blindness or light perception at the most. Thus, children with object perception or measurable visual acuity according to available medical records were not included.

Search procedure

Swedish children with blindness or visual impairments receive support from low vision clinics, habilitation centres and from SNASNE and the two national RCV units located in the cities of Stockholm and Örebro. Blind children are generally assessed by multidisciplinary expert teams at RCV, often before the school start. At the RCV units, files are kept for each child who has undergone assessment and/or received other support. The files contain medical records from low vision clinics and other medical clinics, psychological records from assessments performed at RCV (or, occasionally, other clinics), and pedagogical records. When an individual reaches 20 years of age, these records are sent to a central archive for filing. Thus, for the birth year period 1994–2008, files and records could be retrieved from the two RCV units, and for children born 1988–1993, they were searched for in the central archive. Initially, files of all children with visual impairment born 1988–2008 were examined to identify the children who matched the inclusion criteria. Thereafter, an in-depth search and analysis of all files of the targeted children was performed.

Data collection and analyses

The records were reviewed with regard to year of birth, gender, cause of blindness, gestational age (GA), associated neurological disorders/syndromes, associated neurodevelopmental impairments, cognitive level and type of school placement. This review was performed by a researcher with experience in assessment of children with blindness, in the attempt to validate that assessments and diagnostic procedures concerning additional disabilities seemed accurately performed and the diagnosis valid. In some cases, the records did not include complete information on all examined variables.

The collected data have been analysed by hand and are presented in descriptive statistics and compiled into tables and a graph. The authors considered the studied population with its subgroups too small and heterogeneous for inferential statistics such as correlation or trend analysis.

Ethics

The Regional Ethical Review Board in Stockholm approved the record-based study, which was conducted according to the Declaration of Helsinki. Results are presented at group level only; thus, identification of individuals is not possible.

Results

The total number of blind children identified during this 21-year period was 150, 80 girls (53%) and 70 boys (47%), with a mean of seven children per year (range: 2–12). Of the 150 children, five had died before the age of 18 years. All of these were multi-impaired with severe cerebral damage or disease. We do not have information on the possible additional number of children who might have died at birth or during infancy, for example in the extremely preterm group.

Causes of blindness

The causes of blindness had generally been identified at birth or in early infancy, by ophthalmologists in local clinics. A prenatal cause of blindness was found in 103/150 children (69%) and a peri- or postnatal cause in 44/150 (29%). In three cases (2%), it was not possible to determine whether the cause was pre-, peri- or postnatal. Of the 150 children, 137 (91%) had an antechiasmal cause, while 13 (9%) had a retrochiasmal cause (Table 1).

Table 1. Causes of blindness in the studied population

	Girls (n = 80)	Boys (n = 70)	Total (n = 150)
Prenatal antechiasmal causes (n = 93)
Optic nerve hypoplasia (ONH)	9	14	23
Leber congenital amaurosis (LCA)	13	9	22
Optic nerve atrophy (ONA)	8	8	16
Microphthalmia/anophthalmia	11	5	16
Congenital glaucoma	2	2	4
Retinal dystrophy	2	0	2
Coloboma	1	0	1
Incontinentia pigmenti	1	0	1
Norrie disease	0	1	1
Persistent hyperplastic primary vitreous (PHPV)	0	1	1
Sclerocornea	1	0	1
Unspecified eye malformations	3	2	5
Prenatal retrochiasmal causes (n = 10)
Various cerebral malformations	6	4	10
Peri-/postnatal antechiasmal causes (n = 42)
Retinopathy of prematurity (ROP)	14	22	36
Retinoblastoma	3	0	3
Congenital cataract	1	1	2
Optic glioma	0	1	1
Peri-/postnatal retrochiasmal causes (n = 2)
Cerebral damage due to early trauma or disease	2	0	2
Cause not defined whether pre-/peri- or postnatal (n = 3)
Unspecified eye disease (antechiasmal)	2	0	2
Unspecified tumour (retrochiasmal)	1	0	1

No time trends with regard to the aetiologies in the population during the studied period were possible to identify, due to the small and heterogeneous subgroups. Five conditions dominated in the total population: ROP in 36 children (24%), ONH in 23 children (15%), LCA in 22 children (15%), ONA in 16 children (11%) and micro-/anophthalmia in 16 children (11%). The prevalence of additional developmental disorders was high in all these groups (Table 2). Note that the same individual can be represented in more than one category.

Table 2. Dominating causes of blindness in the examined population, and reported additional developmental disorders in the aetiological subgroups

	Boys/Girls	Cerebral involvementa	Epilepsy	ID	ASD	Motor impairment	Hearing impairment
ROP n = 36	22/14 (61%/39%)	19 (53%)	4 (11%)	23 (64%)	21 (58%)	7 (19%)	2 (6%)
ONH n = 23	14/9 (61%/39%)	2 (9%)	2 (9%)	10 (43%)	16 (70%)	0	0
LCA n = 22	9/13 (41%/59%)	0	0	5 (23%)	8 (36%)	0	0
ONA n = 16	8/8 (50%/50%)	14 (88%)	9 (56%)	10 (63%)	2 (13%)	14 (88%)	3 (19%)
M/A n = 16	6/10 (38%/62%)	6 (38%)	0	6 (38%)	7 (44%)	1 (6%)	3 (19%)

Note

• the same individual can be represented in more than one category.
• ASD = autism spectrum disorder (including autism, Asperger syndrome, pervasive developmental disorder not otherwise specified, and clearly described autistic features), ID = intellectual disability, LCA = Leber congenital amaurosis, M/A = microphthalmia/anophthalmia, ONA = optic nerve atrophy, ONH = optic nerve hypoplasia, ROP = retinopathy of prematurity.

Gestational age

A total of 108 children (72%) had been born at term, and 42 (28%), 25 boys and 17 girls, were born preterm (GA: <37 weeks). Of the 42 preterm born children, three (7%) had been born moderately preterm (GA: 32–36 weeks), three (7%) very preterm (GA: 29–31 weeks) and 36 (86%) extremely preterm (GA: <28 weeks). Mean GA in the preterm group was 26 weeks (range: 23–36 weeks). Data on birthweight were available in 29 (69%) of the preterm children, and mean birthweight in this group was 782 g (range: 522–1300 g). Of the 42 preterm born children, 38 (90%) had ROP as primary cause of blindness.

Cerebral involvement and additional disabilities

Of the 150 children, 50 (33%) had reported specific cerebral involvement, such as hydrocephalus, cerebral malformations or diseases. In 12 of these 50 children, the cerebral involvement was reported as the primary cause of blindness, and the remaining 38 children had other causes of blindness. Epilepsy was diagnosed in 27 of the 150 children (18%).

Seventy-two per cent of the children (108/150) had at least one diagnosed additional disability, the most common being ID, ASD and motor disabilities (table 3). Note that the same individual can be present in more than one category.

Table 3. Prevalence of additional disabilities in the total examined population and in relation to gender

	Total (n = 150)	Girls (n = 80)	Boys (n = 70)
At least one reported additional disability	108 (72%)	50 (63%)	58 (83%)
ID	80 (53%)	34 (43%)	46 (79%)
ASD	47 (31%)	16 (20%)	31 (44%)
Motor impairment	43 (29%)	24 (30%)	19 (27%)
Hearing impairment	13 (9%)	5 (6%)	8 (11%)
ADHD	3 (2%)	2 (3%)	1 (1%)

Note

• the same individual can be represented in more than one category.
• ADHD = attention-deficit/hyperactivity disorder, ASD = autism spectrum disorder (including autism, Asperger syndrome, pervasive developmental disorder not otherwise specified), ID = intellectual disability.

Intellectual disability (ID), ASD and ADHD had been diagnosed by expert teams at RCV or, in a few cases, at other clinics. These disorders were generally diagnosed before school start. A total of 81 children (54%) had more than one additional disability. The most common combinations were ID and motor impairment in 39 cases (26%) and ASD and ID in 36 cases (24%). Among the 150 children, 22% (33/150) had only blindness and no reported coexisting disorder. However, in four of these 33 cases, borderline intellectual function (BIF, IQ: 70–85) was described. In nine of the 150 children (6%) data on coexisting impairments were unavailable or uncertain; hence, we do not know whether these children were multi-impaired or not.

Blindness and autism spectrum disorder

Forty-seven children of 150 (31%) had been diagnosed with autism, AS or (in one case) pervasive developmental disorder - not otherwise specified (PDD-NOS), 31 boys (66%) and 16 girls (34%). If clearly described autistic features were also included, the number increased to 57 (38%), 36 boys (63%) and 21 girls (37%). Of the 57 children with this wider definition of ASD, including prominent autistic features, 36 (63%) were reported to also have ID. The most common causes of blindness in the ASD population were ROP in 21 children (37%), ONH in 16 children (28%) and LCA in eight children (14%) and microphthalmia/anophthalmia in seven children (12%; Fig. 1).

Causes of blindness in the autism spectrum disorder population (n = 57). LCA = Leber congenital amaurosis, M/A = microphthalmia/anophthalmia, ONH = optic nerve hypoplasia, ROP = retinopathy of prematurity.

We also analysed the prevalence of ASD (including clearly described autistic features) in specific aetiological subgroups and found that the prevalence was especially high in four groups: 70% (16/23) in children with ONH, 58% (21/36) in children with ROP, 44% (7/16) in children with microphthalmia/anophthalmia and 36% (8/22) in children with LCA.

Types of school placement

Of the 150 children, 75 (50%) attended different types of specialized schools, mainly schools for students with ID, while a small number attended the state special school for students with visual impairments and multidisability. All these children had reported ID and/or other disabilities in addition to their blindness. Fifty-eight children (39%) attended inclusive educational settings in regular schools. The majority of these were reported to have only blindness, but nearly one-third (17/58) had at least one disability or learning difficulty in addition to the visual impairment, mainly ASD, mild ID, BIF, motor or hearing impairment. Data about school placement were unavailable in 17 cases (11%).

Discussion

This population-based study covered, to our knowledge, the vast majority of children with congenital or early infancy blindness during a 21-year period in Sweden. Hence, the results should be representative with regard to causes of blindness and additional disabilities during recent decades.

Five visual conditions dominated in the group, representing three quarters of the studied population: ROP, ONH, LCA, ONA and microphthalmia/anophthalmia, in decreasing order of prevalence. The most common condition during the studied period was ROP, with an incidence of 1.9 children per year. The incidence clearly decreased during the first part of the 1988–2008 time period (data not shown). This average incidence is similar to the 1.8 child/year found for the period 1980–1994 in Sweden (Jacobson et al. 1998). However, it should be noted that this number may include a small amount of children that might have been born outside Sweden. The incidence of bilateral blindness from ROP in Sweden is currently around one child/year (Feb 2016, personal communication with Gerd Holmström, registrar for the SWEDROP, the Swedish ROP Quality Register).

We found that a vast majority of the children in the study had an antechiasmal cause of their blindness as opposed to children with low vision, where CVI is the most common cause in Sweden (Blohmé et al. 2000). The gender distribution in the total studied population was fairly even, but boys dominated in the ROP and ONH subgroups.

One of the most striking results was the very high rate of multi-impairments in the total group; only 1/5 of the studied group had only blindness with no coexisting disability. This means that beside their blindness, a large number (at least 72%) had reported additional disabilities, in 54% more than one additional disability. This result is in line with the assumption that children with blindness are at a great risk for developmental disorders (Hatton et al. 1997). The most common reported additional disability was ID, diagnosed in more than 50% of the total group. Also, the prevalence of ASD was very high among the blind children; 38% of the children had symptoms within the autism spectrum, 31% meeting the full DSM-IV-criteria for autism, AS or PDD-NOS (APA, 1994). This is considerably higher compared to the general child population in which the prevalence of ASD is around 1% (Lazoff et al. 2010). This result is consistent with earlier research, where approximately 1/3 of all blind children were found to have autism (Cass et al. 1994; Hobson et al. 1997), but the number has not been confirmed in the Swedish population before. In the ASD group, 63% also had ID, and boys dominated. The most common underlying aetiological factors in the ASD group were ROP, ONH, microphthalmia/anophthalmia and LCA; these diagnoses constituted 91% of the causes among the children with ASD. From the opposite direction, in all these four aetiological subgroups the prevalence of autism was also found to be high.

Concerning ONH and ROP, this has been demonstrated before by several researchers. We would like to point out that in this study, septo-optic dysplasia (SOD) was pooled with the ONH group in the data analysis. Septo-optic dysplasia (SOD) is diagnosed when at least two of the features ONH, midline brain defects (e.g. absence of the septum pellucidum) and pituitary dysfunction are present. Previously identified associations with ONH such as developmental delay or ASD seem to be independent of the development of septum pellucidum (Garcia-Filion & Borchert 2013). However, septum pellucidum agenesis is not required for SOD diagnosis (Webb & Dattani 2010). Interestingly, when examining the children with ONH and SOD diagnoses separately in our study, 53% of the children with ONH had various types of ASD, while 100% of the children with SOD met the criteria for a full diagnosis of autism, indicating that SOD diagnosis indeed was set when the disease was more severe than isolated ONH. Regarding ROP, many of the children with this condition in our study were born extremely preterm with very low birthweight and various medical complications and thus are likely to be particularly at risk for developmental disorders such as autism. The co-occurrence of LCA and ASD has been debated, and previous research findings are somewhat contradictory. Leber congenital amaurosis (LCA) is an inherited retinal disease, where an increasing number of specific genes have been identified, encoding various functions critical to retinal developmental and physiologic pathways (Chacon-Camacho & Zenteno 2015). Rogers & Newhart-Larson (1989) reported a high degree of autism in children with blindness due to LCA, but this coexistence was questioned by Fazzi et al. (2007). It is therefore noteworthy that LCA was in fact one of the dominating aetiologies associated with ASD in our study. An association between microphthalmia/anophthalmia and autism has also been reported in genetic cranio-facial malformation syndromes, including CHARGE syndrome (Blyth & Baralle 2011; Pushker et al. 2013).

Implications for practice

Awareness of the high prevalence of additional disabilities in children with blindness in general, and in specific aetiological subgroups, is important for professionals meeting these children in different clinical contexts. It is necessary to monitor blind children's development closely in order to discover signs of atypical development early, initiate psychological assessment when needed, and provide adequate support to the children and their families.

Many children with blindness in Sweden attend inclusive education in local schools around the country, also blind children with additional disabilities. This places high demands on the school system and the individual teachers, who probably will encounter a student with such an unusual disability only once during their entire career. The teachers generally attend courses in teaching methods for students with visual impairments at RCV and receive support from SNASNE's pedagogical advisors. However, the pedagogical support provided to the schools is not always sufficient, according to teachers and parents (de Verdier & Ek 2014).

Children with blindness and ASD, with and without ID, constitute a complex subgroup in need of specific educational measures and support (Gibbons 2005; Jordan 2005; Gense & Gense 2011), but existing teaching methods for children with ASD are often difficult or even impossible to apply, as these methods to a high extent are based on visual skills. The literature about successful methods for children with a combination of blindness and autism is scarce, entailing that much is left to the individual teachers. Further research is needed about successful pedagogical strategies for children with blindness and additional disabilities, especially blindness and ASD.

Limitations

Normally Swedish children with blindness establish early contact with RCV, and therefore, the study should comprise the majority of blind children in Sweden during the studied period. However, possible external omission may concern occasional children who for unknown reasons did not receive support from RCV, for example due to very severe multi-impairment or disease. Regarding internal omission, data concerning specific variables were unavailable in some of the available records. Data on ethnicity could not be included at all due to incomplete or uncertain information. Further on, the small numbers in the subgroups entailed us to abstain from inferential statistics. Also, the relatively small numbers should be taken in consideration when drawing conclusions about different variables in the material.

Conclusions

The results of this study indicate that children with only blindness are in fact very few. In the studied population, the rate of multidisabilities is high, and certain aetiologies seem to be more strongly associated with developmental challenges, mainly ID and autism. Blindness in itself entails considerable implications for a child's development and learning (Warren 1984; Preisler 1997; Sacks & Wolffe 2006). When blindness is combined with other developmental disorders, the situation is even more complex. It is necessary to understand the developmental effects of both the blindness and other coexisting disabilities, in order to correctly interpret the child's behaviour and meet their needs (Jordan 2005). Improved collaboration and coordination between the governmental national support units, local low vision/medical/neuropaediatric clinics and habilitation teams would enable a more adapted support for these children, their families and schools in a lifelong perspective.

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What Are Signs of Autism in a Baby Two Years Old Born Legally Blind

Source: https://onlinelibrary.wiley.com/doi/full/10.1111/aos.13631

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