Congenital deafblindness

Rubella

In the past, the leading cause of congenital deafblindness was rubella, a highly infectious viral illness (also known as German measles).

If a pregnant woman gets rubella, it can cause serious damage to her unborn baby, particularly to their eyes, ears and heart.

However, since routine rubella vaccination was introduced in 1988, and due to the success of the MMR (mumps, measles and rubella) vaccine, the number of babies affected by rubella has fallen dramatically.

Premature birth

Problems associated with premature birth are a common cause of deafblindness. As smoking and excessive alcohol consumption are major risk factors for premature birth, you should avoid both, particularly if you are pregnant.

If you do choose to drink while pregnant, do not drink more than 1-2 units of alcohol once or twice a week. Avoid binge drinking and getting drunk, because heavy drinking is associated with a low-birthweight baby and increases the risk of serious birth defects. A unit of alcohol is equivalent to half a pint of normal-strength lager or beer, a small glass of wine, or a single pub measure (25ml) of a spirit.

Genetic conditions

Some rare genetic conditions can also cause deafblindness, either at birth or in the early years of childhood.

One such condition is known as CHARGE syndrome (see Useful links), which is very rare, affecting about 1 in every 10,000 births. CHARGE syndrome causes a pattern of related birth defects that affect the eyes, heart, nose, genitals and ears, as well as restricting a child's growth.

Acquired deafblindness

Conditions that can lead to both the loss of vision and hearing are rare, but not unknown.

Usher syndrome

The most common condition that causes acquired deafblindness is a genetic condition known as Usher syndrome (see Useful links), which affects around 1 in every 25,000 people.

Children with Usher syndrome are born deaf and then develop a condition known as retinitis pigmentosa as they become older. Retinitis pigmentosa causes the retina - the part of the eye that responds to light - to slowly deteriorate. Eventually, the retina loses the ability to transmit information to the brain and blindness can occur.

Other causes

Acquired deafblindness can often occur as a result of two unrelated conditions that cause loss of vision and loss of hearing, or it can occur as a result of ageing.

For example, as we get older, our vision can get worse as a result of the cells at the centre of the retina deteriorating. This is known as age-related macular degeneration. A similar process can also happen with our hearing, as the cells within the inner ear that help transmit information to our brain become damaged or deteriorate.

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Diagnosing hearing and vision problems 
It is important to accurately diagnosis the remaining levels of sight and hearing in someone who is deafblind.

Total loss of both functions is rare, so you will want to make best use of the senses that remain. For example, if your vision is affected, equipment such as glasses or magnifiers may help.

The two types of test that are commonly used to test your vision and hearing are:

• Clinical tests - these identify how well you can see or hear compared with normal levels of ability. Standardised tests are used, such as the Snellen test, where you are asked to read letters from a chart.
• Functional tests - these study how you actually use your sight or hearing. The tests use a wide range of different visual and audio stimuli plus medical examinations to determine your remaining levels of sight and hearing.

Diagnosing vision loss

If you start to experience problems with your vision, you should first visit an optician (a medical professional who specialises in designing corrective lenses to help with your vision).

The optician will run some tests to see how well your vision compares with normal, and will also be able to detect any eye conditions, such as glaucoma or cataracts.

If a problem is suspected and it cannot be treated using corrective lenses, you will be referred to an ophthalmologist (a doctor who specialises in conditions of the eye). They will run a series of tests and examinations to assess your sight and investigate any underlying conditions that may have caused loss of vision.

Diagnosing hearing loss

If you start to experience problems with your hearing, you should first visit your GP. They will examine your ear for wax, infection or other causes of temporary hearing loss, and treat them accordingly.

If the cause of your hearing loss cannot be established, you will be referred to the ear, nose and throat (ENT) department of your local hospital for further assessment.

There are a series of tests that can be run to assess your hearing, such as an audiometry test, which uses different sound frequencies and volumes to determine what you are capable of hearing.

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Treating deafblindness
Treatable conditions

Some conditions that have lead to deafblindess may be treatable through surgery or by using medicines. For example:

• cataracts can be treated by surgically implanting an artificial lens in your eye
• glaucoma can be treated using eye drops and laser surgery, and
• diabetic retinopathy can be treated with laser surgery, but only in the early stages of the condition, before symptoms become noticeable

Accumulated earwax is one of the most common causes of hearing loss and can be treated with ear drops.

If hearing loss is caused by otitis media (an infection of the middle ear), it can usually be treated with antibiotics

Treatment plan for non-treatable conditions

If the conditions that have lead to deafblindess are not treatable, a treatment plan will be drawn up. Goals of the treatment plan may include:

• Preserving and maximizing any remaining sensory functions.
• Providing you with training so you can retain as much independence as possible. For example, you may be provided with support and advice about how to navigate safely in the outside environment, using a cane or a guide dog.
• Teaching you communication systems that you can use to compensate for your loss of vision and sight.

The treatment plan will depend on the exact circumstances of your deafblindness. For example:

• you may be born deafblind,
• you may have adapted to being blind, but then start to lose your hearing,
• you may have adapted to hearing loss, but then start to lose your vision, or
• you may lose both your hearing and vision as you get older (this is the largest group of deafblind people).

There is a range of equipment that can be used to assist both vision and hearing.

Vision aids

Vision can be improved using glasses and magnifying lenses. There are also everyday items, such as telephones and keyboards, that have been specially designed for people with reduced vision. The Royal National Institute of the Blind (RNIB) has a comprehensive list of equipment that is available on their website, as does Sense. For more information, see Useful links (right).

If you are a computer user, all operating systems have settings designed for people with reduced vision. You can also download free software from the Browsealoud website that will read aloud the text from speech-enabled websites. Many of the major websites and most public information sites are now speech enabled.

For websites that are not speech enabled, you may need to buy additional software to read documents and emails. Both the Sense and RNIB websites provide details of appropriate software.

Most libraries stock a selection of large-print books and 'talking books' (where the text of the book is read aloud and recorded onto a CD). The RNIB also offer a talking-book service, where a wide range of talking books can be delivered to your house for a small subscription fee.

Hearing aids and implants

Hearing loss may be improved with the use of hearing aids. A hearing aid consists of a microphone to pick up sound and an amplifier to increase the sound. Hearing aids are a helpful way of improving communication, but they cannot restore hearing to normal.

People with profound hearing impairment may benefit from a cochlea implant. The cochlea is a coiled, hollow tube inside you inner ear that enables you to hear. A cochlea implant transmits sound directly into your ear's auditory nerve through an electrical wire that is implanted into the cochlea.

For more information on hearing aids and cochlear implants, see Health A-Z: treating hearing impairment

Communication systems

There are several communication systems that can be used by deafblind people, which are outlined below.

Deafblind manual alphabet

The deafblind manual alphabet involves spelling out words using special gestures on the deafblind person's hands, such as touching the tip of their thumb to spell the letter 'A'.

Block alphabet

The block alphabet is a simple communication method. Each letter of a word is spelt out in capital letters onto the deafblind person's palm. This is used by a variety of deafblind people, including those who may not be able to use the deafblind manual alphabet.

Hands-on signing

Hands-on signing is a communication method that uses an adapted version of British Sign Language (BSL). The deafblind person places their hands over the hands of the person who is signing. This method is often used by people with Usher syndrome once their vision starts deteriorating, as they have BSL as their first language.

Braille

Braille uses a series of raised dots to represent letters, or groups of letters. A wide range of Braille publications and specially designed computers are also available that allow you to type and print Braille documents.

Moon

Moon is a communication system that is similar to Braille, but it uses raised symbols to represent words, rather than dots.

Tadoma

Tadoma is a communication method whereby the deafblind person places their thumb on a person's lips and their fingers on their jaw line so that they can feel the vibrations of the person's throat. The combination of these two tactile (using the sense of touch) sensory inputs enables the deafblind person to build up a good understanding of what is being said. However, it is not used by many deafblind people.