Have you ever thought that a tiny fungus in the soil could affect your eyesight? Today we are going to talk about something that is rarely heard of, but is very important to know. This is called Presumed Ocular Histoplasmosis Syndrome , or POHS for short. Although it is a bit of a long name, let's keep it simple.
First of all, what is Histoplasmosis?
Simply put, histoplasmosis is an infection of the lungs caused by a fungus called Histoplasma capsulatum . This fungus is usually found in soil. It is most common in soil that contains a lot of bird or bat droppings (aka droppings). It is most common in parts of the United States, such as the Ohio and Mississippi River valleys. However, this fungus can also be found in other parts of the world, especially in areas where there is a lot of bird or bat droppings.
So, what is ocular histoplasmosis syndrome (POHS)?
This condition called POHS affects the eyes as an extension, or complication, of the same histoplasmosis that infects the lungs. What happens is that the fungus somehow travels through the blood and ends up in the back of the eyes. That's when the problem begins.
How does ocular histoplasmosis affect the eyes?
Most of the time, the fungus `(Histoplasma capsulatum)` doesn't make everyone sick when they breathe it in. For some people, it goes inside the body and disappears without any symptoms. However, unfortunately, if this fungus gets into the eyes, two problems can occur:
- Choroidal Neovascularization is an abnormal growth of blood vessels that can affect the function of the eye. While this may sound a bit complicated, in simple terms, it is the formation of new blood vessels inside the eye that are not needed.
- Scars can form inside the eye.
Both of these can seriously affect your vision.
Who is at higher risk of developing POHS?
Let's see who is more likely to develop this condition:
- As mentioned earlier, those living in the Ohio or Mississippi River valleys in the United States are at higher risk. However, even in Sri Lanka, it is good to be aware of this for those who live in areas with high levels of bird and bat droppings.
- For those who catch birds like chickens, for those who work around chicken coops. Chickens are raised in many homes in Sri Lanka.
- People who work with soil, such as dusty areas on farms and construction sites , may have fungi like that.
- Those who use tobacco or have a history of using it are also at higher risk.
Another risk factor is a weakened immune system. It can be caused by:
- For those with certain diseases, for example, arthritis and multiple sclerosis .
- For pregnant women.
- For the elderly and young children.
- When using certain medications, especially those taking immunosuppressants.
Why does histoplasmosis develop in these eyes?
We've said before, it starts in the soil where the fungus `(Histoplasma capsulatum)` is. Think about it, when you dig a field, dig a hole, or clean a chicken coop, the fungus in that soil is stirred up and added to the air. Then we can breathe it in. That's how the lungs become infected. But, researchers still haven't figured out exactly how it gets from the lungs to the back of the eyes.
What are the symptoms of POHS?
In the early stages of this condition, there are no symptoms. That's the most dangerous thing. However, when the fungus `(Histoplasma capsulatum)` affects the eyes and starts forming new blood vessels called `(Choroidal Neovascularization),` your vision starts to be affected.
You may feel things like this:
- The difference in the size of the same object seen by the two eyes. As if one eye sees it as smaller and the other as larger.
- Blind spots in vision.
- Blurred vision or loss of vision without pain.
- Colors may not appear as they should (colors may appear faded).
- Flashes or flickering before the eyes.
- Straight lines, such as road markings, window bars, and lines in a book, appear stretched and wavy.
If you experience something like this, you should definitely see an ophthalmologist as soon as possible .
How do you find out if you have POHS?
When you see an ophthalmologist, the first thing they do is examine your eyes carefully, especially the back of the eye, to see if you have any of the following:
- Scar tissue
- Swelling
What happens if there are signs of histoplasmosis syndrome in the eyes?
If you have these signs, you may need to have a dilated eye exam, which involves dilating your eyes with medicine . This allows you to see more clearly what's inside your eye. The doctor can then look for:
- Abnormal blood vessels
- Has fluid accumulated?
- Inflammation
- Small white spots
In addition, you may also have a test called Fluorescein Angiography . This involves injecting a special dye into a vein in your arm. This dye travels with your blood to the blood vessels inside your eye. A special camera then takes pictures. This can help determine if you have abnormal new blood vessels (Choroidal Neovascularization).
Does everyone need treatment for POHS?
No, not everyone will need treatment. Unless the Histoplasma capsulatum fungus has affected your vision in some way, you may only need regular monitoring.
How is histoplasmosis of the eyes treated?
This is a bit special. Antifungal medications are not usually given for this. Because, although it is caused by a fungus, it is not a fungal infection inside the eye, but a reaction to it.
Instead, the treatment is to stop the abnormal new blood vessels from forming (Choroidal Neovascularization). There are two main ways to do this:
1. Anti-vascular endothelial growth factor (anti-VEGF) treatment: This involves injecting a substance called anti-VEGF directly into the affected eye. This medication stops the abnormal blood vessels from growing. This can help reduce symptoms. However, it may take several injections to see results.
2. Photodynamic therapy: In this, a light-sensitive drug called verteporfin is injected into a vein in your arm. The drug binds to the abnormal blood vessels in the eye. Then, low-power laser beams are used to activate the drug. The abnormal blood vessels are destroyed.
The most important thing is that both of these treatments should be done under the supervision of a specialist ophthalmologist.
What does the future hold for those with POHS? (Results)
Treatment for histoplasmosis of the eyes can prevent further vision loss. That's a good thing. However, some people may not be able to fully regain their previous vision.
Can POHS affect future health?
Yes, even after successful treatment, POHS symptoms can recur. However, if they do recur, they may not be as severe as before. People with weakened immune systems are especially at risk of this type of relapse.
How to protect yourself from POHS?
We can't see the fungus (Histoplasma capsulatum) when it's in the air. So it's very difficult to avoid breathing it in. However, if you're at high risk for histoplasmosis, it's best to stay away from certain things.
Avoid these things:
- Walking in places like caves, because there may be bats there and there is little ventilation.
- Going into the chicken coop and hanging around it.
- Working with soil that may contain bird or bat droppings.
What else can I do to stay safe?
If the fungus `(Histoplasma capsulatum)` gets into your lungs, it can be difficult to prevent it from spreading to your eyes. The best thing to do is to get your eyes checked regularly. That way, if there is a problem with your eyes, you can identify it at an early stage.
What is it like to live with POHS?
If you have ongoing vision problems, you may be able to get help from a service called low vision rehabilitation . A therapist will teach you ways to do everyday activities safely. For example, they may give you advice on how to reduce the risk of tripping or slipping at home.
Remember as a summary (Take-Home Message)
Okay, so I hope you can remember some important points from what we've talked about.
- POHS is a condition caused by a fungus called `(Histoplasma capsulatum)` affecting the eyes.
- This fungus is most abundant in soil with abundant bird and bat droppings .
- You are at higher risk if you work around chicken coops, work with soil, use tobacco, or have a weakened immune system .
- If you experience symptoms such as blurred vision, seeing black spots, or seeing straight lines , see an ophthalmologist immediately.
- If treated on time, vision can be prevented from worsening.
- Although it is difficult to completely protect yourself from POHS, it is very important to avoid risky situations and have your eyes checked regularly.
So, take care of your eyes. Because, eyes are the most precious asset we have!
` histoplasmosis, POHS, eye diseases, fungal infections, vision impairment, choroidal neovascularization, eye health
💬 අදහස් (0)
තවමත් කිසිදු අදහසක් පළ කර නොමැත. ඔබේ අදහස පළමු වරට මෙහි එක් කරන්න.
ඔබේ අදහස එක් කරන්න