Best disease affects the macula which is part of your retina at the back of your eye which you use when reading, writing or watching TV. There is no current treatment for Best disease although research is on-going in the area of gene therapy which may lead to a treatment in the future.
This page contains a summary of our information on Best disease. To read our full information, download our factsheet:
Best disease is an eye condition that affects a tiny part of the retina at the back of your eye, called the macula. Best disease causes problems with your central vision but does not lead to total loss of sight and is not painful. Best disease affects the vision you use when you're looking directly at something, for example when you're reading, looking at photos or watching television. Best disease may make this central vision distorted or blurry and, over a period of time, it may cause a blank patch in the centre of your vision. Best disease will not usually affect your peripheral (side) vision.
Best disease is a type of macular dystrophy and is also called “Best vitelliform macular dystrophy”. Macular dystrophies are inherited eye conditions meaning they are caused by a fault in a gene.
Best disease can affect both men and women. It usually occurs in both eyes, but it may not affect vision to the same extent in each eye. Sometimes it only affects one eye. Best disease can start to cause changes at the macula between the ages of three to 15 although it does not usually affect vision until later on in life. The sight loss caused by Best disease can take many years to develop and some people with Best disease can continue to read into their forties, fifties or well beyond.
Best disease is a genetic condition. This means that it is caused by a "faulty" gene which may be inherited from a parent or occur as a new fault in the gene.
Best disease can be caused by a fault in a gene known as BEST1 (also known as VMD2).
Researchers have identified hundreds of different faults within this one gene which can lead to several macular dystrophies, collectively known as bestrophinopathies. These include:
All genes come in pairs. You inherit one copy of the gene from each of your parents to make a pair. Your genes give the cells in your body the instructions they need to work well and stay healthy. When a gene is faulty, the genes do not give their instructions correctly to the cells and the cells then don’t develop or work as they should.
There are several ways a faulty gene can be passed down from parents. These "ways" are also known as patterns of inheritance.
Best disease is inherited in a dominant pattern.
Dominant inheritance means that a disease is inherited from only one of your parents. When the "faulty" gene lies in its pair with the normal gene from your other parent, it is the dominant one and "switches on" the trait or condition. It is "dominant" over the other "normal" gene inherited from the other parent.
This means that, if a person has one faulty copy and one healthy copy of the gene, they will have Best disease themselves and will have a 50 per cent chance of passing the faulty gene on to each child that they have. If a child doesn’t inherit the faulty Best disease gene, they cannot pass it on to their children.
More recently researchers have discovered that some faults in the BEST1 gene can be inherited in a recessive pattern. This means that you need to inherit two copies of the faulty gene (one from each of your parents) in order to be affected by the condition. This is a rarer type of macular dystrophy, known as autosomal recessive bestrophinopathy.
In most cases of the adult-onset form of vitelliform macular dystrophy, the cause is unknown. However, in some cases, faults can be found in either the BEST1 or in other identified genes including PRPH2, IMPG1 or IMPG2. Many people with adult-onset vitelliform macular dystrophy do not have a fault in any of these genes and the cause remains unknown.
The inheritance pattern of adult onset vitelliform macular dystrophy is not yet clear. Not everyone who has the condition has a family history and not everyone who inherits a faulty gene develops symptoms. If someone does develop symptoms, they usually begin between the ages of 30 – 50 with blurred or distorted central vision. The condition progresses very slowly, and many people may retain good vision into later life.
If there is Best disease in your family, you may find it helpful to speak with a genetic counsellor, a consultant geneticist or an ophthalmologist (hospital eye doctor) with a specialist interest in genetics.
Genetic testing can help to confirm the gene responsible for Best disease and how it has been inherited. Genetic counselling can help you understand how Best disease has been passed through your family and the chances of passing it on to future children.
Genetic counselling is a free NHS service. You can ask your GP or your ophthalmologist to refer you to your local genetic service.
Early signs of Best disease usually develop between the ages of three to 15. In these early stages Best disease doesn’t always have much effect on vision, so a child may not notice a sight problem. Sometimes it is picked up at an eye examination where an optometrist can see changes in the macula before vision is affected.
Sometimes someone may notice a change in their vision and an eye test then confirms they have changes at the macula which could indicate Best disease. Even though someone may have changes to their macula because of Best disease at an early age they may not develop vision problems until much later in life - often over the age of 40.
There are five stages to Best disease which can be seen by the optometrist or ophthalmologist when they look at the macula. None of these stages cause eye pain.
Stage 1: At this stage your macula looks healthy and no change can be seen. There may be subtle changes to a layer underneath the macula but there is generally no effect on vision.
Stage 2: This stage is called the vitelliform stage. At this stage there is a blister on your macula area which looks similar to an egg yolk. Although the optometrist or ophthalmologist can see these changes often there is no effect on vision or very slight changes to vision at this time. Usually this stage occurs between the ages of three and 15 years of age
Stage 3: This stage is called the pseudohypopyon stage. With this stage some of the yellow matter which causes the egg yolk-like blister can breakthrough a layer under your retina. This leads to a cyst forming under the retina. Again, there may be little change in level of sight. This stage is usually seen in the teenage years.
Stage 4: This stage is called the vitelliruptive stage. In this stage the lesion begins to break up and can cause damage to some of the cells in the layers of your retina. At this point you may start to experience changes in your vision. You may start to notice that straight lines look wavy or have problems with reading small print.
Stage 5: This stage is the final stage of Best disease. It is called the atrophic stage. The yellow material which caused the lesions begins to withdraw and disappear. However, it leaves behind scarring and damaged cells on your retina. At this stage your sight is more seriously affected, and you may find reading difficult.
These are the classic stages of Best disease however some people develop another stage, called choroidal neovascularisation (CNV). This stage develops during the atrophic stage when the eye starts to try to fix the damage to the macula by creating new blood vessels. Unfortunately, these new blood vessels are very leaky which causes them to bleed and this eventually can lead to formation of scar tissue and further deterioration in sight. However, CNV does not occur in the majority of cases.
You can have Best disease for a long time without having any sight difficulties. Your sight is not normally affected until stage 4 or 5 which may not develop until over the age of 40, although it can occur earlier in someone's late twenties or early thirties. It isn't possible to know exactly when or how much your sight will be affected as it can vary from person to person.
Unfortunately, there is no treatment for Best disease at the moment. Although many advances are being made in identifying genes responsible for Best disease this hasn’t yet led to a treatment.
A small minority of people with Best disease may develop new blood vessels on or under their macula, medically called choroidal neovascularisation (CNV).
The risk of developing CNV is possibly increased by head trauma. Therefore, it makes sense to take extra precaution in situations where you might get a bang on the head, for example, avoiding contact sports or wearing a bicycle helmet when cycling.
New blood vessels can be treated with laser and possibly with an anti-VEGF drug injection. Although treating new blood vessels may not lead to a great improvement in sight, it often helps to prevent further damage to the macula and to sight.
Anti-vascular endothelial growth factor medications (anti-VEGFs) are a category of drugs which stop or reduce the growth of new blood vessels. This can slow their leakage and slow down vision loss. Anti-VEGFs are not yet automatically available on the NHS for people with vitelliform macular dystrophy related CNV, but your ophthalmologist would be best placed to decide what treatment is needed in your case.
Gene therapy is currently being researched as a possible treatment for different types of inherited macular dystrophies. Gene therapy aims to replace the faulty gene with a new gene that works properly. Normal genes are injected into the retina using a harmless virus to carry the genetic material. The hope is that that affected retinal cells then begin to work properly and the damage is either stopped or reversed. A lot of this research is in early stages and may take many years before it could possibly become an established treatment, although this kind of research is a positive step forward.
There is no specific research as of yet to show that diet can help to slow down the progression of Best disease. However, a good diet full of fresh fruit and vegetables can help with eye health in general. Smoking is known to accelerate other forms of macular disease so it would be sensible to stop smoking as this possibly could help delay progression of Best disease too.
Even though there is no current treatment for Best disease it is very important that you receive long-term follow-up care to monitor your condition and its progression. It is also very important to have regular checks with the hospital or optometrist to ensure that any CNV development can be detected as early as possible to allow treatment if needed.
If you have been diagnosed with Best disease and you notice a sudden change in vision in either of your eyes you should see your optometrist or let your eye clinic know straight away. This is because some people can develop CNV and if this happens sight-saving treatment may be possible.
If you have slight changes in your vision, then you should arrange for an eye examination with your optometrist. They are trained to detect any eye problems and, if necessary, can refer you to an ophthalmologist at the hospital.
People with Best disease have a much higher chance of being long-sighted. Long-sightedness means your eyes have difficulty focusing near to. Long-sightedness can be easily corrected for with glasses.
Although glasses or contact lenses cannot correct vision problems caused by Best disease, your optometrist might be able to improve your long-sightedness or short-sightedness with glasses to help give you the best vision possible. Your optometrist can check your glasses prescription at your eye examinations to make sure your glasses, if needed, are the right strength for you.
It is important to remember that many young people who have Best disease may well have good vision for a long time and may only need help when and if their Best disease progresses to the later stages.
Being diagnosed with an eye condition can be very upsetting. You may find that you are worried about the future and how you will manage with a change in your vision. We’re here to support you every step of the way, and to answer any questions you may have – just get in touch with our Sight Loss Advice Service.
The Macular Society has local groups which meet throughout the country and also offer a telephone counselling service. Sometimes it can help to talk about your feelings or share with people who may have had similar experiences.
Best disease can cause problems with your central vision. However, most people with Best disease have some vision that they can use everyday and using your vision won't make the disease worse.
There are lots of things that you can do to make the most of the vision you have. This may mean making things bigger, using brighter lighting or using colour to make things easier to see. Ask your ophthalmologist, optician or GP to refer you to your local low vision service, which can provide you with magnifiers to help with reading, advice on lighting and tips on how to make the most of your peripheral vision for everyday tasks to help make the most of your sight.
Local social services should also be able to offer you information on staying safe in your home and getting out and about safely. They should also be able to offer you some practical mobility training to give you more confidence when you are out.
1. Beat the Best – a USA-based online non-profit awareness and support group for people with Best on Facebook.
2. Although there is no specific UK group for people and families affected by Best disease, the Macular Society is the national charity for anyone affected by central vision loss.
3. Genetic Alliance UK is the national charity working to improve the lives of patients and families affected by all types of genetic conditions.