Visual Impairment Scotland Research

Visual Field Loss in Children

Blaikie AJ, Ravenscroft J, Buultjens M, Dutton GN, Visual Impairment Scotland Research Group

Royal College of Ophthalmologists Congress
Birmingham, May 2003

Purpose

To the authors' knowledge there are no specific descriptive studies on visual field loss in childhood. The purpose of this study was to describe the characteristics of children with visual field loss in a population of children with visual impairment.

Methods

The electronic database of Visual Impairment Scotland’s (VIS)1 childhood notification system was analysed. Information on the education and health of children was acquired from parents, educational institutions and health professionals.

Results

Frequency and Character of Visual Field Loss
333 children with ‘significant visual impairment’ (visual acuity worse than 6/18 and/or any visual field loss and/or cognitive visual dysfunction) were notified to VIS between March 21 2001 and September 21 2002. 23% (77/333) of these children were described as having some kind of visual field loss. The different types of visual field loss are described in Figure 1.

The three most common types of visual field loss described were ‘peripheral’ (34%), ‘lower’ (29%) and hemianopia (21%).

Anatomical Site of Impairment
Figure 2 describes the anatomical sites of impairment.
The two most common sites of impairment within the visual system were the brain (64%) and retina (17%).

Conditions Associated with Visual Field Loss
A wide range of conditions (24) were described in the 77 children with visual field loss (Table 1). The three most common causes of impairment described by health professionals were cerebral visual impairment (16 cases), cerebral palsy (9 cases) and periventricular leucomalacia (7 cases).

Aetiology
Just under half the children (47%) acquired the impairing condition prenatally and one quarter (25%) around the time of birth. Very few children (14%) acquired the cause of the impairment after the first month of life.

Visual Function2
Nearly two thirds (62%) of children with visual field loss also had visual acuity of worse than 6/18.

Additional Disabilities
Most children (70%) with visual field loss had additional disabilities.

Registration and Record of Needs Status
Complete educational information was available on 50 of the 77 children with visual field loss. 70% (35/50) of these children were registered blind or partially sighted and 52% (26/50) had a Record of Needs in place.

Conclusions

In this study visual field loss was common (23%) and comparable in frequency (18%) to a study from Sweden3. A wide variety of conditions (24 different conditions) were responsible for the field loss and in this study often present in association with reduced visual acuity (63%) and additional disabilities (70%). Despite this many children are neither registered blind or partially sighted (30%) or have a legal statement of educational needs in place (48%).

The VIS database can now offer accurate and current information on the number and characteristics of children with visual impairment in Scotland. The information can be used to plan appropriate integrated service provision and inform professionals involved in the education of children with visual impairment.

References:
1. http://www.viscotland.org.uk/

2. http://www.visaid.dk/english/eng_class.asp

3. Blohme J, Tornqvist K, Visual impairment in Swedish children. II. Etiological factors. Acta Ophthalmol Scand. 1997 Apr;75(2):199-205.

VI Scotland
Scottish Sensory Centre
Moray House School of Education
University of Edinburgh
Holyrood Road
Edinburgh
EH8 8AQ
Telephone: 0131 651 6078
Fax: 0131 6501 6502
E-mail: viscotland@ed.ac.uk
Web: www.viscotland.org.uk

John Ravenscroft
Manager
VI Scotland, SSC