Best disease is a form of juvenile macular degeneration. While there is no cure for it, there are options that can slow the progression of the disease and improve visual function.
Best disease, also known as Best vitelliform macular dystrophy, is a genetic form of juvenile macular degeneration. In macular degeneration (AMD), the macula, the central part of the retina, is progressively damaged, causing loss of central vision. The prevalence of Best disease is estimated at 1 in 16,500 to 1 in 21,000 people. According to another estimate, about 1 in 15,000 people suffer from it.
People with Best disease and other conditions that cause vision loss may benefit from low vision optometrists who undergo advanced training in this field. Their advanced knowledge of the latest vision technologies helps improve vision both practically and functionally.
They may recommend you use low vision aids such as magnifying devices, CCTVs, tinted lenses, prisms, and digital devices. Once the doctor understands what matters to you, they will help you find the devices that will maximize your vision for the tasks you care about. People with this disease and similar conditions have now been able to do things they never thought they could with the help of state-of-the-art custom low vision optical glasses and devices.
With Best disease, the macula which is responsible for central vision is affected. It is vital to have a healthy macula so that you can drive safely and read road signs. Even though vision is affected by the disease, for most people it does not impair their ability to drive. The use of low vision glasses allows many patients with this condition to keep their licenses until late in life.
In the majority of states, low vision optometrists can assist you in maintaining your license and regaining your driving ability through bioptic telescopes customized to your prescription.
A bioptic telescope consists of a pair of glasses with a telescope attached above your normal line of sight. These can be attached to your regular eyeglasses and can be used either for one or both of your eyes. Bioptic lenses magnify images just like binoculars and help you see things better. Using these lenses allows you to see things that are much further away, which is one of their main benefits.
The average age at which Best disease begins is between 5 and 10 years old, but it can vary from person to person. In the beginning, individuals with this condition have normal vision, but may experience the following symptoms with time:
Many people with this disorder are unaware that their vision is declining and may be diagnosed during a routine eye examination. Others experience significant loss of vision, due to blood vessels forming under the macula and retina. It is possible for each eye to suffer from different degrees of visual loss. In most cases, individuals with Best disease have one eye more severely affected than the other, but with the assistance of a low vision optometrist can still engage in daily activities such as driving well into their old age.
Best is inherited genetically from one parent through an autosomal dominant pattern. That means that a faulty gene is responsible for the condition. A defective gene inherited from one parent dominates the healthy gene inherited from the other parent. Another possibility is that the mutated gene was not passed down from the parent to the child, in which case the child would not inherit the disease. If one parent has the disease, there is a 50/50 chance of inheriting it.
Best disease can be diagnosed by looking for lesions that resemble egg yolks at the back of the eye, seen in the vitelliform stage. There are other tests available to confirm the diagnosis.
Best disease progresses through six stages. They are discussed below:
Stage I - Pre Vitelliform
At this point, you are likely to not be experiencing symptoms and you have not yet developed the yellow material below your retina.
Stage II - Vitelliform
This term vitelliform means shaped like an egg. At this stage, yellow material is forming an egg-like shape. You may still have good vision.
Stage III - Pseudohypopyon
It is possible that the yellow material that was forming under the retina at stage 2 will develop into a cyst.
Stage IV - Vitelliruptive
Your retina may begin to be damaged by the yellow material, and your vision may be affected.
Stage V- Atrophic
As the yellow material disappears, it leaves scars and damaged cells behind. This stage is considered to be the final phase of Best disease by some researchers.
Stage VI - Choroidal neovascularization or CNV
There are some researchers who believe that CNV is the final stage of Best disease, while there are others who believe that it is a complication of it. About 20% of people with Best disease develop CNV. Choroid neovascularization refers to the development of new blood vessels. Those blood vessels may leak, causing your vision to deteriorate.
Unfortunately, as of now, there is no effective medical or surgical treatment for Vitelliform macular degeneration. There is currently research being conducted on gene therapy for the treatment of different types of inherited macular dystrophies. By replacing the faulty gene with a new functioning gene, gene therapy aims to correct the problem. The research is in the beginning stages and may take a while before it could potentially become a useful treatment, however this kind of research is a positive step in the right direction.
One of the most exciting trials is in the field of gene therapy used for treating Best’s disease. Research was done at the University of Pennsylvania and the University of Florida that demonstrated the efficacy of treating best disease through gene therapy in Dogs. The approach taken has also been used in the FDA approved retinal gene therapy for Leber’s congenital amaurosis. The hope is that this approach that has been shown to work in both dogs and in other FDA approved treatments for retinal disease, will also translate into an effective treatment for Best’s disease. Clinical trials are underway, and your low vision optometrist or ophthalmologist will inform you if the treatment becomes available.
Head trauma may increase the risk of developing the Best disease. Therefore, If you're at risk for a head injury, it's a good idea to take extra precautions, such as avoiding contact sports and wearing a helmet while cycling.
Laser therapy and anti-VEGF injections can be used to treat new blood vessels. It may not lead to a significant improvement in sight, but treating blood vessels can prevent the macula and eyes from further damage.
There is evidence that smoking accelerates other forms of macular disease, so stopping smoking might help delay progression of Best disease as well. Currently, no research has indicated that diet can help to slow the progression of the Best disease. A diet high in fresh fruit and vegetables, however, may be beneficial for maintaining eye health.
Best disease, also known as Best vitelliform macular dystrophy, is a genetic form of juvenile macular degeneration. In macular degeneration (AMD), the macula, the central part of the retina, is progressively damaged, causing loss of central vision. People with Best disease and other conditions that cause vision loss may benefit from low vision optometrists who undergo advanced training in this field. Their advanced knowledge of the latest vision technologies helps improve vision both practically and functionally. They may recommend you use low vision aids such as magnifying devices, CCTVs, electronic devices, lighting, tints, and prisms to help you regain your independence.