How To Detect Ocular Toxoplasmosis?
Ocular toxoplasmosis can cause blurred vision, sensitivity to light, and pain in the eyes. However, the diagnosis can be complex; here we explain why.
Ocular toxoplasmosis is a disease produced by a parasite called Toxoplasma gondii . It is a very common infection that affects almost 500 million people worldwide. However, not all infected people develop this specific eye pathology.
People with symptoms of toxoplasmosis are those with weakened immune systems. Or who got the infection before birth, in the womb. However, ocular toxoplasmosis can be difficult to detect and often progresses to blurred vision or even blindness.
What is toxoplasmosis?
To be able to understand toxoplasmosis, we will first explain how infection with this parasite occurs. The Toxoplasma gondii tends to multiply and become lodged in cats. So when the cat defecates, it expels its eggs in the feces.
It is one of the forms of transmission. However, infection of most people occurs because this parasite is often present in food. For example, in fruits, vegetables and meat. In other words, when you eat a contaminated product without cooking it, you can get the infection. On the other hand, Toxoplasma gondii is also found in water or in milk.
Another form of contamination concerns pregnancy. When a pregnant woman first comes into contact with toxoplasma, it can cross the placenta and reach the baby.
The latter case is most often associated with ocular toxoplasmosis. Depending on when the contact takes place during pregnancy, the damage to the fetus will be more or less severe. During the first trimester, this may increase deformities and complications.
How does ocular toxoplasmosis occur?
The infection is usually asymptomatic at first. However, reactivation may occur some time after contact. This would cause a first lesion in the eye causing a scar, which often goes unnoticed.
When the infection reactivates, the specific symptoms of ocular toxoplasmosis begin to appear. This happens because the parasite lodges in the retina, the part of the eye that allows the interpretation of images and the sense of vision. The retina becomes inflamed ( retinitis ) and vision is compromised.
A study conducted on the subject states that recurrent ocular toxoplasmosis is the most common. However, it can also appear in relation to AIDS or under continuous treatment with corticosteroids or immunosuppressants.
How to detect ocular toxoplasmosis?
The diagnosis of ocular toxoplasmosis can be very complex. It should be performed on a clinical basis. In other words, by observing the lesions inside the eye. Indeed, the available examinations can only confirm whether or not there has been contact with the parasite.
For example, serologies, which show whether there are antibodies against the infection, only indicate whether the person has been infected at some point. But, as we mentioned before, many people have been infected and have not developed ocular toxoplasmosis.
What an ophthalmologist observes directly is a focal lesion of the retina with a scar that also affects the choroid. The choroid is another membrane that is part of the eye.
Laboratory tests can help guide the diagnosis, but they do not confirm it. It is essential that a thorough eye examination is carried out, and that it is carried out by a specialized professional so as not to miss certain signs.
What is the treatment for ocular toxoplasmosis?
Ocular toxoplasmosis causes blurred vision, pain in the eyes, and sensitivity to light. In some cases, it can even lead to blindness. Unfortunately, there is currently no treatment that can reverse the lesions.
The therapy helps prevent further damage to the retina and further recurrence. It prevents the parasite from replicating and spreading further by the combination of antiparasitics, such as pyrimethamine and sulfadiazine.
In addition, we usually add the drug Methylprednisolone, which is a corticosteroid that helps reduce inflammation. Additionally, folic acid supplements are prescribed in order to avoid the side effects of pyrimethamine.
Prevent injuries
The most effective way to prevent ocular toxoplasmosis is through preventive measures against this parasite. Doctors recommend cooking all foods to avoid contamination. Also, in the case of pregnant women, great emphasis is placed on taking special care of cats.
Finally, we must keep in mind that, when faced with any symptom, the first thing to do is to go to an ophthalmologist. Detecting lesions early on can help prevent eye damage from worsening and multiplying.
