Has your vision gradually decreased and everything started to become blurry? Maybe it started in one eye, and after a few months, the other eye also became this condition? You must be very worried about these things. Today we are going to talk about a rare disease that can cause these symptoms, but is called Leber Hereditary Optic Neuropathy, or ``(LHON)``.
What is Leber hereditary optic neuropathy (LHON)?
Simply put, Leber hereditary optic neuropathy, or LHON for short, is a genetic condition that is passed down from generation to generation. The main thing that happens is that you lose your sight. When most people inherit it, their vision starts to blur and then gradually worsens over about six months. Sometimes, it starts in one eye and then affects the other eye a few months later. It usually starts in late childhood or young adulthood. Unfortunately, many people with LHON can become legally blind. This means that their vision is reduced to the point where they are legally considered blind.
It's also called Leber's disease. That's because the doctor who first studied it was Dr. Theodore Leber. The word "hereditary" means that it's something you inherit . "Optic neuropathy" means that it's a disease that affects your optic nerve . Your optic nerve is like the cable that goes from a camera to your brain. The things you see with your eyes, that is, visual signals, are carried to your brain by this optic nerve. That's where the brain "sees." So, if this optic nerve is damaged, that's one of the main ways you can lose your vision.
Are there different types of LHON?
Yes, if LHON mainly affects your optic nerves, meaning that vision loss is the only symptom, it is called the standard LHON condition. This is the condition that most people with Leber disease have.
However, very rarely , some people may have other symptoms along with LHON. These can affect other parts of their nervous system, and sometimes even their heart. Doctors call this condition "Leber plus." This is a bit more complicated, because it can cause other health problems, not just vision problems.
How common is LHON?
It is not known exactly how common LHON is. However, estimates suggest that one in 25,000 to 50,000 people may have the condition. It is also notable that 80% to 90% of people with LHON are male .
What are the symptoms of LHON (Leber's disease)?
LHON causes painless, subacute vision loss, which means it happens gradually over several months. The first changes you may notice are in your central vision . Central vision is what you see when you look straight ahead - the vision you use to drive, read, and recognize faces. Your central vision may start to appear blurry, or you may develop a blind spot in the middle of your field of vision. This may start in one eye and then spread to the other eye.
This condition will get worse over the next few months. You may also start to lose your color vision - meaning you may not see some colors or be unable to distinguish them. The vision loss usually stabilizes within six months to a year after the first symptoms begin. By this time, most people's visual acuity may be 20/200 or worse, which is the level of being legally blind. You may still have some light perception, but you will have to learn to live with low vision. Imagine, it feels like the world is suddenly going blurry.
What are the symptoms of "Leber's plus"?
As we mentioned earlier, people with "Leber's plus" may experience a variety of other symptoms in addition to vision loss. Some of these include:
- Movement disorders , for example tremors.
- Balance and coordination problems (ataxia) . Like staggering when walking, or not being able to grasp things properly.
- Cardiac conduction problems , for example, irregular heartbeats (arrhythmias).
- Symptoms of multiple sclerosis (MS) , such as muscle weakness and extreme fatigue.
What are the causes of Leber hereditary optic neuropathy?
Leber's hereditary optic neuropathy is a mitochondrial disease . It's a genetic disease that you inherit through the mitochondria in your cells. Now you might be wondering what mitochondria are. Simply put, mitochondria are like little power generators inside your cells. They take in oxygen and nutrients and produce the energy your cells need to function. It's like a generator that powers our house.
So, in mitochondrial diseases, this energy-producing process is disrupted. Then the cells don't get the energy they need. Because of this, some cells can stop working properly, or even die.
When your mitochondria aren't working properly, the parts of your body that rely on mitochondrial energy are the first to suffer. The most important of these are the parts of your eyes, especially your optic nerve . If enough of your mitochondria are defective, these parts don't get the energy they need to function properly. This is what happens in Leber's disease. The result is that your optic nerve gradually deteriorates . This is how you lose your sight in LHON.
How is LHON inherited?
LHON is caused by a gene mutation in the DNA in your mitochondria. Specifically, mutations in the genes MT-ND1, MT-ND4, MT-ND4L, or MT-ND6 cause LHON.
Importantly, you get all of your mitochondria from your mother, not your father. Therefore, only mothers can pass this mutation on to their children. Even if the father has the disease, he will not pass this mutation on to his children.
However, not everyone who carries this gene mutation will develop symptoms of `(LHON)`. Therefore, some people may not even know that they carry this gene mutation. This is a bit complicated, isn't it? This means that even if the mother has this gene mutation, the child may or may not develop symptoms.
Are there any risk factors for developing LHON?
This is also a very important question. Researchers still don't have a clear idea why some people with the gene mutation develop symptoms of `(LHON)` and others don't.
However, some evidence suggests that physiological stress and environmental toxins may contribute to the onset of symptoms. This means that these external factors add additional stress to systems that are already under stress due to the genetic mutation. Over time, the idea is that these stresses can build up and eventually lead to symptoms.
Here are some things that could be risk factors:
- Smoking.
- Alcohol use.
- Exposure to environmental toxins (for example, some pesticides, industrial chemicals).
- Having other systemic illnesses.
- Severe psychological stress .
How is LHON diagnosed?
Your eye care specialist will do a series of standard eye exams to check your vision and find the cause of the problem. They may not be able to see anything wrong with your eye or optic nerve in the early stages, which is within the first six months after symptoms start. The damage becomes more obvious after the first six months after symptoms start.
If your doctor suspects LHON, he or she will recommend genetic testing . This is the only way to know for sure if you have one of the genetic mutations we talked about. This test is the only way to confirm the diagnosis.
Is there a treatment or complete cure for LHON?
Unfortunately, there is currently no cure for LHON. The only drug currently approved by the FDA is a synthetic form of Coenzyme Q10 called Idebenone. Randomized controlled trials have shown some improvement in visual acuity in people with LHON. Other similar drugs are also in the research phase.
Researchers are also studying gene therapy , which could be used as a future treatment for LHON. But these are still in the research stage. So, at this point, it is difficult to hope for a complete cure. However, there are ways to manage the symptoms and control the further deterioration of vision to some extent.
What is the outlook with LHON?
When vision loss occurs due to LHON, it can be rapid, severe, and often permanent . Many people have to learn to live with low vision. Low vision is a moderate to severe degree of vision impairment, but it does not mean complete blindness. Moderate low vision is a visual acuity test of 20/70. Severe low vision is a visual acuity test of 20/200 or less. This is actually a fairly wide range of visual acuity that you can eventually achieve.
Whether you are on the moderate or severe side of this range is often a matter of luck. Treatment can make a difference, but the gene mutation you have makes the biggest difference. Some people with LHON unexpectedly regain some of their vision after about a year of vision loss. The likelihood of this type of vision recovery varies with different gene mutations. However, even if you do regain some vision, you will likely still have to live with low vision.
Is there a way to prevent LHON?
Although most people who inherit the genes associated with LHON never develop vision loss, there is currently no known way to prevent it. Taking antioxidants and avoiding neurotoxins such as alcohol and tobacco may reduce your risk, but this has not been proven.
Remember, all women who have these genes will pass them on to their children. Genetic counseling can help you consider this risk. If someone in your family has this disease, or if you find out that you have this gene mutation, it is very important to get genetic counseling before starting a family.
Whether you know about a family history of LHON, or it's something completely unexpected for you, losing your vision all of a sudden can be a scary and heartbreaking experience. You and your doctor may not understand what's happening at first. But once you know about it, you'll have a lot to learn as you adjust to your new reality.
Remember, you are not alone in this journey - there is a world of resources to help you. There are organizations, equipment, and mental health support available to those with low vision.
Finally, things to remember
Okay, so I hope you have some idea about the `(LHON)` we talked about. This is a bit of a complicated topic, but it's very important to be aware of it.
- (LHON) is a hereditary disease that damages the optic nerve and causes vision loss.
- This is caused by a genetic mutation in mitochondrial DNA, which is inherited from mother to child .
- Symptoms usually appear at a young age, and vision gradually decreases without any pain.
- In addition to vision, other nervous system problems can occur in the condition called "Leber plus" .
- Things like smoking and alcohol can be risk factors for the development of symptoms.
- There is currently no specific cure, but there are medications like `Idebenone` and ways to adapt to low vision.
- If you have any doubts about this, definitely see an ophthalmologist and get a genetic test.
- Living with this condition can be challenging, but you are not alone, get help.
I hope this information is helpful to you. If you have any further questions regarding this, don't hesitate to talk to a doctor. Stay healthy!
` Leber hereditary optic neuropathy, LHON, vision loss, optic nerve, genetic mutations, mitochondrial diseases, hereditary blindness
💬 අදහස් (0)
තවමත් කිසිදු අදහසක් පළ කර නොමැත. ඔබේ අදහස පළමු වරට මෙහි එක් කරන්න.
ඔබේ අදහස එක් කරන්න