A Condition which affects Hearing and Sight.
by Mary Guest, Head of Usher Services at Sense.
What is it ?
Usher syndrome is an inherited condition which results
in hearing loss and a progressive loss of vision from Retinitis pigmentosa
(RP). The hearing loss is thought to be congenital, and ranges from moderate
to profound. RP can occur without hearing loss. The condition is named
after a British ophthalmologist, C.H. Usher, who in a paper in 1914
described several cases in which the link between congenital deafness and
RP was stressed. However, as far back as 1860 workers such as von Graef
and Liebreich in Berlin were aware of the link between congenital deafness
and RP, especially in consanguinous marriages.
This term describes not one disease but a group of hereditary
diseases of the retina. The retina is the light sensitive tissue inside
the eye in which the first stages of 'seeing' take place. With RP the retina
slowly degenerates and loses its ability to transmit pictures to the brain.
In advanced stages characteristic clumps of pigment appear on the retina
and can be seen through an ophthalmoscope.
The first symptom to appear in RP is night blindness;
this may also be coupled with difficulty in adapting to bright light or
rapidly changing light conditions. Difficulty with dark adaptation can
occur in childhood, and although it may be noticed it is seldom attributed
to RP, but rather clumsiness, stupidity or even lack of carrots!
Narrowing of Field Vision,
In one form of retinal degeneration the rod cells which
lie on the periphery of the retina gradually lose function and fail to
transmit information about changes in light levels and shapes of objects
on the periphery. This loss of visual field or 'tunnel vision', as this
is commonly known, means that the individual loses his or her ability to
locate objects which are not directly in front, so that for instance, he
may still be able to read the bus timetable but unable to locate the bus
station without help.
Loss of Central Acuity,
Another form of retinal degeneration causes the cone cells to be affected initially so that the individual can no longer see the details of the object in front of him and he will be unable to read print. This type of loss is referred to as macula degeneration and in this case low vision aids such as hand magnifiers and magnification of print using a closed circuit television screen as well as large print texts may be helpful.
In both forms of retinal degeneration the extent and speed at which vision deteriorates is extremely variable. In some individuals the breakdown of the retina is so marked that at the age of six they require special education for the visually impaired and are on the blind register.
Others may have noticed no severe restriction of vision until they reach their thirties and it is not uncommon for some to retain their reading vision well into old age.
In the Usher syndrome form of the disease the retinal
condition tends to be diagnosed later rather than earlier in the life of
the deaf person and affected individuals may not know they have RP until
they have reached young adulthood.
Usher is transmitted genetically by an autosomal recessive
gene. To produce a child with Usher both parents must carry the recessive
gene. Autosomal implies that the gene is not sex linked and so both males
and females are equally affected by the condition. In recessive inheritance
both parents carry the gene, but are not aware that they are carriers until
the condition is diagnosed in their children. The child with Usher syndrome
has two recessive genes for the trait and will transmit these genes to
Transmission of Usher syndrome,
If a person with Usher marries another with the same syndrome, all their children will be expected to have the same condition. If a person with Usher marries a person without the condition, the children will be unlikely to have the condition, but they will be carriers. If a person with Usher marries another deaf person, the latter should be tested to see if they have the condition, albeit mildly.
A child who is identified as being at high risk for Usher
syndrome should be referred immediately to an ophthalmological clinic which
has the capacity for full diagnostic testing.
What are the Problems,
By the age of 20 most deaf people will be in training or already employed. Those who have RP may well be doing work which will eventually prove difficult or even dangerous to carry out.
The rate at which vision will degenerate over the third decade of life is difficult to predict, there is therefore a question about when to change course. Should the keen young motor mechanic and student nurse carry on, and have perhaps 10 to 15 satisfying years of work, or should they change to something that they can work at even when their vision has become severely restricted?
"Most deaf people have a negative attitude towards blindness. For very understandable reasons deaf people universally feel the worst possible handicap that can befall a human being is blindness. Ironically, blind people feel the same way about deafness."
Vernon's apt words embody the dilemma which affects those who are both deaf and blind. As the deaf person contemplates the future with RP he or she is already leaving the world of the deaf and entering the world of the blind, yet neither world wants to know him. Contrary to popular opinion, people with one disability are not predisposed to being sympathetic and understanding towards those with a different condition from their own.
Deaf people are largely dependent on sight to aid communication, as the visual field narrows it becomes more difficult for the affected person to follow signs and lip read more than one person. Young adulthood is the time to be out and about pursing sports and leisure activities and socialising with friends. The young deaf person who also has RP will find that night blindness places severed limitations on their social life, on opportunities for meeting people and on developing friendships.
A deaf friend who, for some inexplicable reason, walks into lamp posts, trips over curb stones and needs to hang on to an arm is an embarrassment and liability to his friends. Thus, even before the diagnosis of RP is confirmed this young deaf person has begun to withdraw from social life an the pattern of isolation is being established.
Regrettably, in some cases RP is not diagnosed until a serious incident such as a road traffic accident suggests that the patient's vision should be examined more thoroughly. The victim not only has to face recovery from an accident but also the knowledge that he has an untreatable eye condition.
All these factors, social isolation, uncertainty about
employment, the emotional reaction of parents and facing an unknown future
make it hard for this young person to adjust. The youngster often faces
these difficulties with little constructive help from the army of professionals
who may be consulted, and they are fortunate if they find anyone who truly
understands the condition of Usher syndrome, who can offer the constructive
counselling that will be needed over the ensuing months and years.
Reaction of Family and Friends,
A diagnosis of Usher syndrome for the individual poses many problems and also for the family. The reaction of friends and relations can largely determine how the victim will handle the future and how well. Parents who have faced the first hurdle of deafness with their child, who have spent the growing years struggling with language, lip reading, speech development and hearing aids and learning sign language, together with the emotional output involved will begin to feel that this great effort has been rewarded as the young adult starts out in life. It is at this point, as the son or daughter becomes more outgoing, starts work, starts driving perhaps, or wants to get engaged that the awful truth is often discovered.
Reactions to the diagnosis of RP vary. Some parents are so shocked that they can hardly bring themselves to talk about it to each other. If the diagnosis is made when only one of the parents is present, he or she not only has to bear the initial shock, but also has the unenviable task of trying to convey the news to the spouse. The consultant may not have had enough time to explain in terms that the parent con comprehend the nature of Usher syndrome, and the stricken parent leaves the consulting room with many half formed questions till unanswered. It is often left to the parent to break the news to their child and many are at a loss as to how this should be done. They may not disclose the diagnosis immediately; some parents carry the burden of knowledge for months or even years only revealing the truth when their child is planning to marry or take a hazardous job.
Some families cannot accept the prognosis of possible blindness. The term 'blind' is an inadequate word because in lay terms it means someone who cannot see anything. Unless the nature of RP as a visual handicap is explained these parents take comfort in the knowledge that their son or daughter can see to read and ignore the fact that he or she may only have 25% of his central vision still functioning. This attitude can lead them to react inappropriately to the practical and emotional needs of the affected child.
An understandable reaction to the diagnosis of Usher is for the family to search for treatments. They may have been told kindly or otherwise by the consultant that there is at the moment no known cure for RP, yet they have read newspaper reports about treatment around the world which claim to arrest the condition. Sadly, many families spend the next vital years pursuing these claims, raising money and making big financial sacrifices in order to pay for travel and treatment yet the real need for rehabilitation, career guidance and help with daily living skills for the young person are neglected.
Although there is no known effective treatment for RP,
the future is not entirely without hope. The last decade has seen research
into the causes of RP increase rapidly, with several major centres in the
USA and Canada undertaking specific studies into retinal degeneration.
This interest has been reflected in Europe particularly where major RP
research is being done in four centres in London, Birmingham, Glasgow and
What Can be Done?,
The need for early diagnosis is essential if the traumatic effect of discovering this potentially blinding disease is to be reduced. However, this can only occur if the professionals who see the deafblind child during their school life are aware of Usher's and know what to look for. The major symptoms that should lead to an immediate referral are night blindness, extreme sensitivity to light and/or tunnel vision; also these children may have a problem with balance. The family doctor, the class teacher and the audiologist who see the deaf child regularly need to be aware that the congenitally deaf child is in a high risk group for Usher. Other professionals such as the ophthalmologist, the otologist, the optician and the psychologist need information too, if early diagnosis is to be achieved.
The congenitally deaf constitute a high risk group within
the population but those who are still at school and in units for the deaf
around the United Kingdom are traceable. Screening tests which measure
the field of vision could be administered between the age of 11 and 16
along with other checks such as dental, chest, hearing and developmental,
which all children, within the state education system, undergo.
Better Figures Needed,
Figures for the incidence of Usher syndrome in Britain
are incomplete; in the USA more statistical work has been done but even
there the figures are tenuous. (5) About 3 per 100,000 people in the US
have Usher. Of all those who have a congenital hearing impairment, 3 to
6% are victims of Usher. Of the 70,000 to 100,000 population who have RP
in the US, one out of four has Usher syndrome. Thus, Vernon estimates that
there are 17,500 to 25,000 people who will be deafblind due to Usher syndrome.
As Vernon rightly points out, these figures show that Usher syndrome is
all too common among deaf people. Ignorance amongst professional people
who deal with deaf children about this syndrome is widespread. (6) This
must change. The need for earlier diagnosis is paramount if benefit is
to be had from educational guidance, career counselling, psychological
coping techniques and genetic counselling.
Better Handling at Diagnosis,
While it is true that at present the medical professional can offer no effective treatment for RP, they can and should offer time, sympathetic handling and honesty to the people in their are. What goes on in the consulting room when the patient and his family are told about the diagnosis of Usher syndrome is critical to the way in which they will all handle the situation later. Too often the facts are given in a cold even brutal manner and the bewildered family is ushered out of the room before they have time to think. If the deaf patient communicates by sign language and finger spelling and no communicator is present it is possible that he has only grasped half of the truth. If the parents are too upset to explain, the 'victim' is left in the highly unsatisfactory state of knowing something is badly wrong, but not knowing what. It is important that a sign language interpreter used to the medical terminology is made available at these appointments.
Much of this anguish can be avoided if the patient and
the family are given a proper explanation of the condition and allowed
time with the help of a communicator (if necessary) to ask questions and
understand the implications of the disorder. The medical social worker
should be involved to introduce the family to organisations, aids and benefits
which may be needed in the future. It is very important at this stage that
the individual and the family are given the support they need and not left
to face the future 'as best they can'. It may help the newly diagnosed
person and his family to be linked with a family who are handling the situation
reasonably well, in order to talk about their concerns.
Education and Career Guidance,
If Usher is diagnosed before the young person has left school the teaching staff will need advice on handling the pupil with RP. Informing the school that the child has Usher syndrome is not enough, precise information about the field of vision, the extent of central loss and whether he needs protection from extraneous light will be required.
There are some Low Vision Aids such as magnifiers, binoculars and Closed Circuit Television which could benefit the student's visual performance and he should be referred to the Low Vision Aid Clinic at the nearest hospital for an assessment.
The class teacher will also need advice on the best lighting conditions for the particular student together with use of contrasting tones to make things easier to see.
Career Guidance must be realistic but not too restrictive; labels like 'deafblind' to an employer mean 'unable to hear or see anything'. With Usher's this is rarely the case, particularly in the young adult. What needs to be answered is, 'can the employee, given the restricted hearing and vision he has, do the job?' The employer needs to know that certain aids such as CCTV can be loaned through the Placement Advisory C Teams to help the employee.
Certain jobs involving driving or use of dangerous machinery
should be avoided, and again early diagnosis will help prevent these choices.
As vision deteriorates, help will be needed with mobility
and daily living skills such as cooking. Braille can be introduced even
if it is only used for labelling and the family helped with finger spelling.
However, 'blind' skills should not be suggested until they are really necessary.
For example, Braille should be introduced when the user understands the
need for it and still has sufficient vision to enable learning to proceed
This service will be an ongoing requirement possibly through the life of the individual as he attempts to adjust to decreasing vision. Centres where Usher syndrome is understood and where they can meet others similarly affected to talk out their difficulties, need to be planned. For a 'victim' of Usher syndrome, the knowledge that he is not the only one with his condition, that he can meet with his 'own kind', that he is 'understood' and does not have to 'keep up a front', is invaluable as has been evidenced from recent residential meetings held by Sense and the Retinal Awareness Group.
To summarise: it is necessary to improve treatment and
services for people with Usher syndrome. This improvement will come only
when professionals dealing with deaf people know about this condition,
when we know how many people have it, when we stop looking at bits of people
and attend to the whole and when we show a deeper concern for those who
must live their lives deprived of much of their sensory input.