University of Edinburgh
 

Visual Impairment Scotland Report

Chapter 6 The causes of childhood visual impairment

Anatomical site

Key Points

The brain is the most common anatomical site (47%) of visual impairment.

Children with visual impairment due to a condition of the brain are more likely (86%) to have additional disabilities than children in whom visual impairment is due to the eye or optic nerve (31%).

Cerebral Palsy and Cerebral Visual Impairment are the most common (22.2%) conditions leading to childhood visual impairment.

The second most common cause is Albinism (13.2%)

Children with visual impairment due to brain disorder are the single largest group of children notified to VIS. That this group was also much more likely to have additional disabilities such as physical, learning or hearing impairment has major implications for social and special educational service provision.

6.1 Anatomical Site

The site of pathology within the visual system that leads to childhood visual impairment depends greatly on the economic status of the country in which the children live56. In developing countries the anterior segment of the eye is the most common site of pathology. In more affluent developed countries the brain is expected to be the most common site. This group of children however, is thought to be the most likely, not to be included in social service and educational visual impairment registration systems57,58.

The anatomical sites that cause childhood visual impairment are detailed in Table 6.1. The brain is the most common anatomical site (47%) of visual impairment in children. This distribution of anatomical sites is similar to the findings of the inclusive Swedish register25 and the recent British Ophthalmological Surveillance Unit (BOSU) study55.

table 6.1

As expected there were few children (4%) with pathology of the anterior segment (cornea and lens) leading to significant visual impairment. Conditions affecting the whole globe were the second most common group (21%). This includes conditions such as albinism, microphthalmia and coloboma.

The third largest group was visual impairment due to retinal disorders (18%). This includes many inherited disorders such as retinitis pigmentosa and cone dystrophies as well as retinopathy of prematurity.

Consistent with the comprehensive notification systems developed in many Scandinavian countries and BOSU, VIS has identified that the brain is the most common site of visual impairment in children in a developed country. This is the first time this has been shown in Scotland.

6.2 Additional Disabilities

Children with visual impairment due to a condition of the brain are much more likely to have additional disabilities than children in whom visual impairment is due to eye or optic nerve disorders.

figure 6.1

Children with visual impairment due to brain disorder are the single largest group of children notified to VIS with significant visual impairment. That this group is also much more likely to have additional disabilities such as physical, learning or hearing impairment has major implications for social and special educational service provision.

6.3 The Causes Of Childhood Visual Impairment

There were 66 different childhood visually impairing conditions notified to VIS. The specific conditions named by each child’s health professional as the primary cause of visual impairment are described by anatomical subgroups in Table 6.2. Cerebral Palsy and Cerebral Visual Impairment were the most common causes of visual impairment (74 cases representing 22.2% of the total number of children). The second most common cause was Albinism (44 cases representing 13.2% of the total).

table 6.2

table 6.2

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