Medical Information about Periventricular Leucomalacia
by Dr Andrew Blaikie for VI Scotland
This document is written with the minimum use of medical terms and jargon. It is impossible to avoid all medical terms but where we have used them we have attempted to explain them as clearly as we can. Although the information is intended to describe most aspects of the condition each child is different and there will always be exceptions to the rule. As far as we can determine these pages are true and accurate and have been written in good faith.
What this information is not for
This document is not a substitute for a consultation with a Health Professional and should not be used as a means of diagnosing a condition.
We hope the information will help you to:
- Have a better understanding of the condition
- Know what tests and treatments are normally available
- Know when to seek professional advice
- Be able to discuss the condition in a more informed way
- Make the most of consultations with carers, teachers and health professionals
- Be reassured and more able to cope
Due to staffing limitations we are not able to offer telephone or email advice to parents of children.
What we see is made in the brain from signals given to it by the eyes. What we see is in fact made in the brain. The brain makes sight from signals given to it by the eyes.
What is the normal structure of the eye?
The eye is made of three parts.
- A light focussing bit at the front (cornea and lens).
- A light sensitive film at the back of the eye (retina).
- A large collection of communication wires to the brain (optic nerve).
A curved window called the cornea first focuses the light. The light then passes through a hole called the pupil. A circle of muscle called the iris surrounds the pupil. The iris is the coloured part of the eye. The light is then focused onto the back of the eye by a lens. Tiny light sensitive patches (photoreceptors) cover the back of the eye. These photoreceptors collect information about the visual world. The covering of photoreceptors at the back of the eye forms a thin film known as the retina. Each photoreceptor sends its signals down very fine wires to the brain. The wires joining each eye to the brain are called the optic nerves. The information then travels to many different special 'vision' parts of the brain. All parts of the brain and eye need to be present and working for us to see normally.
The brain of a premature baby (born before their expected due date) is prone to damage from lack of blood and oxygen. This is because the normal blood supply has not yet spread to all parts of a premature baby's brain.
The brain has within it spaces that are filled with water. These water spaces are called 'ventricles'. The parts of the brain around the water spaces often have the poorest blood supply. The medical word for 'around' is 'peri'. 'Periventricular' means 'around the water spaces'.
It is these periventricular areas in premature babies that are most likely to suffer damage from lack of blood and oxygen. If damage occurs the nerves in this part of the brain die. The area softens and becomes scarred. On a picture of a head scan the scars appear white. 'Leuco' is a medical word for white and 'malacia' for softening. Periventricular Leucomalacia is the description of how a premature baby's brain looks on a scan that has suffered damage from lack of blood and oxygen. It means 'white soft areas around the water spaces of the brain'. Periventricular Leucomalacia (PVL) can lead to visual impairment.
Why might PVL lead to Visual Impairment?
The periventricular areas of the brain help carry information from the eyes to the special vision parts of the brain. They also help carry signals within the brain between all the special vision parts. Scarring in these areas can slow or block passage of information. This can lead to a type of visual impairment known as Cerebral Visual Impairment.
There are no medicines or surgical treatments that will fix or improve brain damage. There are however lots of things that can be done to help children with CVI make the most of their vision.
We use our vision to get around, learn new things and to meet other people and make friends. It is important to consider what your child's particular problems with vision might be now and in the future.
If your child has been prescribed spectacles, contact lenses or a Low Visual Aid (LVA) it is important that they are encouraged to wear and use them. This will help your child see more clearly and ensure the vision parts of the brain grow and develop. It will also motivate a child to explore the world and move.
Problems at school may be due to some of the reading books being hard to see. This often means it takes longer and more effort to do the work. If the size of print is increased and letters and words spaced more widely most children will find schoolwork easier. Good bright lighting and crisp black print on a clean white background will also make things easier. Sometimes placing reading books on a slope, which tilts the print towards the child, will improve reading speed as well. When reading it can be helpful to read one line at a time through a 'letter box' placed over the page. Placing a piece of blue tack below the line they are reading, at the beginning of the next sentence, can help some children find their way back to the start of the next line more quickly.
Some children may also benefit from using a computer program while reading. The program only shows one word of a sentence at a time. The word is in the middle of the computer screen. This reduces the need for fast eye movements. It can increase reading speed and reduce tiredness. One program is called Ace Reader. There are many others. A demonstration can be downloaded from www.acereader.com.
It is also worth watching carefully to find out what the smallest toys are that a child can see and play with. Then try to only play with toys that are the same size or bigger. Placing one toy on a plain background will often help children see it more readily. Placing lots of toys of different size and colour close together on a patterned background can make them very difficult to see.
Recognising facial expressions can often be difficult. It is worth trying to find out at what distance facial expressions can be seen and responded to. Then always try to talk and smile from within this distance. This helps a child to learn what facial expressions mean and to copy them. There is a special part of the brain that helps children 'make sense' of faces. Sometimes this part is also damaged. These children may have difficulty responding to smiling even if their vision is clear enough.
If the child has visual field loss try to place objects in the part of the child's vision that is working.
Cerebral Visual Impairment commonly occurs in children who have difficulty controlling both head and eye movements. Careful positioning of the head to prevent it falling to the side or falling forward can sometimes improve vision.
Infants and young children need to learn about the world around them. Home visiting teachers, physiotherapists and occupational and speech therapists may all add to the child's care and education. It is important to continue the programmes that they recommend. If the child is involved in family activities vision can improve and new skills can develop.
Even if a child has very poor vision many useful and practical things can be done to improve the ability of the child to get around, interact with other children and learn.
Who wrote these documents?
These pages are the consensus of opinion of many different people. They include parents of visually impaired children, visually impaired children themselves, Community Paediatricians, Ophthalmologists, Educationalists and Psychologists.
The main author and person responsible for their content is Dr Andrew Blaikie who was an Ophthalmology Research Fellow with Visual Impairment Scotland and is a member of the Royal College of Ophthalmologists.