University of Edinburgh
 

Medical Information on Optic Atrophy

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.

Medical Information on Optic Atrophy

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.

What is Optic Atrophy?

If damage occurs to the retina or optic nerve then some of the wires wear out and disappear. This is known as Optic Atrophy. By looking into the eye with a special instrument all these wires can be seen 'end on' as they exit the eye and pass to the brain. This is the 'head' of the optic nerve. If none of the wires are damaged then the 'head' of the optic nerve looks yellow and pink. If many wires are missing then the optic nerve looks pale and white. This is the common appearance in children with optic atrophy.

What is the cause of Optic Atrophy?

There are many different causes of optic atrophy. Often no cause can be identified and the condition is unexplained. This is often called 'Idiopathic'. Recognised causes of optic atrophy include:

  • Problems during pregnancy, labour and the early days of a baby's life that result in poor oxygen and blood supply to the baby can lead to optic atrophy
  • Infection of a child's brain (meningitis) can sometimes cause optic atrophy
  • Some specific optic atrophy conditions are known to run in families
  • Other optic atrophy conditions can occur for the first time in a family as a result of marrying a cousin or a more distant relative
  • Occasionally some diseases of the baby's metabolism can cause optic atrophy
  • Some drugs if taken during pregnancy are associated with the development of optic atrophy
  • If pressure is applied to an optic nerve by a growing mass then optic atrophy can occur.

How does Optic Atrophy affect a child's vision?

Most young children will feel their vision to be 'normal' as they have never known anything else but their own visual world. At first they assume that everyone else has vision the same as their own and do not realise that other people see things differently. Depending on the cause of the optic atrophy the vision can sometimes improve as the child gets older or with treatment of the cause.

Optic Atrophy can affect vision in different ways. If only a small number of wires in only one optic nerve have been damaged and the optic nerve is almost normal then the child may also have normal vision. If both optic nerves have lost most of the wires then the child will have reduced sharpness of vision and may only see bright lights and large shapes. Optic atrophy often initially causes problems with central vision and colour vision.

Sometimes children with optic atrophy can develop fast to-and-fro movements of the eyes (nystagmus). A squint can also develop.

What can be done to help?

Wearing spectacles can often improve vision. If the vision is worse in one eye than the other sometimes patching the better eye will help to improve the vision in the other. Special low visual aids may also be provided. These can all improve the child's vision.

How can parents, family, friends and teachers make a difference?

We use our vision to get around, learn new things and to meet other people and make friends.

Most children with Optic Atrophy have few problems getting around. The way they act can give the impression that their vision is normal. It is important however to be aware of their own special problems with vision.

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 most children will find schoolwork easier.

It is 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.

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.

Even if a child has very poor vision many useful and practical things can be done to help.

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.

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