Deafblindness

Page last reviewed: 13/07/2011

 

Deafblindness is a term that describes a number of conditions involving both vision and hearing problems.

It is sometimes called dual-sensory impairment.

Some people with deafblindness may have some vision and hearing; others may have a total loss of vision and hearing. Many people will have a combination of the two, such as total deafness plus some loss of vision.

Types of deafblindness

There are two main types of deafblindness:

  • congenital, where somebody is born with both visual and hearing problems, and 
  • acquired, where somebody loses some or all of their hearing and sight at some stage during their life.

There are more than 100 causes of congenital and acquired deafblindness (see Causes page for more information).

In the case of acquired deafblindness, it is rare for both impairments to occur at the same time. For example, with a rare genetic disorder called Usher syndrome, a person is born deaf and then begins to lose their sight later in life. Or, a person may be born blind and start to lose their hearing as they get older.

Personal treatment plan

The fact that there are so many variations of deafblindness means there is no single treatment for the condition. Instead, a personal treatment plan will take into account each individual's needs and requirements (see Treatment for more information).

How common is it?

Most people who are deafblind are aged 75 years and older.The organisation Deafblind Ireland estimates that, in Ireland, between 3200 and 4000 are deafblind but this number will increase as the the population ages.

Outlook

Despite the profound challenges faced by deafblind people, many live full and active lives. For example, the famous deafblind writer, Helen Keller, won worldwide admiration for her books and campaigns for women's and workers' rights, until her death in 1968.

Page last reviewed: 13/07/2011

Hearing loss

Some people who are deafblind will have experienced a sudden and total loss of hearing, which can occur as a result of infection or injury. Others will experience a gradual deterioration of hearing.

People with hearing loss may experience the following:

  • speech and other noises sounding muffled and indistinct
  • an inability to understand conversation when there is background noise
  • needing to turn up the volume on the television or radio
  • asking others to speak more loudly, clearly, or slowly

Loss of vision

Some people with deafblindness may have a condition, such as diabetic retinopathy, that causes gradual blindness. Diabetic retinopathy is a condition related to diabetes, where excess levels of glucose in the blood cause damage to the blood vessels in the eyes (for more information, see diabetic retinopathy).

Other conditions, such as cataracts (a condition where the lens of the eye becomes clouded) and glaucoma (a condition where changes in pressure inside the eye damages the optic nerve) can cause a progressive loss of vision. Common symptoms of conditions that cause a progressive loss of vision include:

  • pain in the eyes
  • blurring of vision
  • halos appearing around sources of light
  • severely reduced night vision
  • problems seeing in bright sunlight or well-lit rooms.

When to contact your GP

See your GP if you notice any deterioration in either your vision or hearing. Some conditions, such as cataracts, can be successfully treated before significant damage to your sight occurs.

You should also see your GP if you have repeated ear infections, because this could increase your risk of hearing loss.

Page last reviewed: 13/07/2011

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, because of the success of rubella vaccine and 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. For the sake of your baby's overall health the best advice ,if you are pregnant or trying to conceive ,is not to drink any alcohol. For further information see www.drugs.ie or www.drugsandalcohol.ie

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 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.

Page last reviewed: 13/07/2011

It is important to accurately diagnose 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 your local audiology department or 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.

Page last reviewed: 13/07/2011

Treatable conditions

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

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

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

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

Living with Deafblindness

A treatment plan will be drawn up if you are living with deafblindness. Goals of the treatment plan may include:

  • Preserving and maximising 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 National Council for the Blind of Ireland (NCBI) has a comprehensive list of equipment that is available on its website.

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 The NCBI offers a wide range of braille, audio and large print books, newspapers and magazines to members.

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 do not restore hearing to normal.

People with profound hearing impairment may benefit from a cochlea implant. The cochlea is a coiled, hollow tube inside your 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 cochlea implants, see 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, for example 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 on to 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 Irish Sign Language (ISL). 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.

Useful Links

Page last reviewed: 13/07/2011

Rubella and pregnancy

If you are considering trying for a baby, you should have your immunity to rubella tested by your GP before becoming pregnant, as a rubella infection could lead to your unborn baby becoming deafblind.

It is also important that you ensure that your children receive the MMR vaccine. If they catch rubella, not only will they be at risk of developing serious complications such as a lung infection (pneumonia), they could also spread the disease to a pregnant woman, putting her unborn baby at risk of deafblindness.

Eye tests and screening

It is recommended that you have your eyes tested at least once every two years to check for any problems.

If you are diabetic, you should be offered an annual test for diabetic retinopathy, which is a condition where excess blood sugar and high blood pressure causes damage to the eyes If diabetic retinopathy is detected early enough, it can be treated effectively using laser treatment.

However, by the time diabetic retinopathy begins to cause noticeable symptoms, it can be much harder to treat; hence the need for early detection.

Preventing ear damage and infection

It is important to protect your ears because any damage could affect your hearing. Also, try to keep your ears clean and dry as this can help prevent some types of ear infections. You may also find the advice outlined below useful.

Avoid damaging your ears

  • Do not insert cotton wool buds, or other objects, into your ears. Wax works its way out naturally, and cotton buds should only be used to sweep around your outer ear (pinna).
  • If you find that ear wax build up is a problem, you should have it removed by a healthcare professional.
  • Prolonged exposure to loud noise damages your hearing, so try to avoid high noise levels and wear propietary ear-defenders/ear plugs when this is not possible.

Keep your ears dry and clean

  • Do not let water, soap, or shampoo get inside your ear when you wash. Also, while bathing and showering, wear a shower cap in order to avoid water, or soap, entering your ears.
  • After washing, use a hairdryer, on a low setting, to dry your ears. Never push the corners of a towel into your ears to dry them because this can cause damage.
  •  If you swim regularly, wear a swimming hat that covers your ears, or use ear plugs.

Glossary

Fever
A high temperature, also known as a fever, is when someone's body temperature goes above the normal 37°C (98.6°F).
Immune
The immune system is the body's defence system, which helps protect it from disease, bacteria and viruses.
MMR
MMR stands for measles, mumps and rubella. It is a vaccine that prevents measles, mumps and rubella by making the body produce antibodies that will fight off the viruses.
Congenital
Congenital means a condition that is present at birth- the condition could be hereditary or develop during pregnancy.
Heart
The heart is a muscular organ that pumps blood around the body.
Vaccination
Vaccination or immunisation is usually given by an injection that makes the body's immune system produce antibodies that will fight off a virus.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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