Ebola virus and eye

What causes the Ebola virus and how is it transmitted? How are our eyes affected?;

What is the Ebola virus?;

The Ebola virus, also known as haemorrhagic fever, affects humans, with an average mortality rate of 50%.

It first appeared in 1976 in the Democratic Republic of the Congo. Since then, 23 outbreaks of the virus have been recorded in Africa, with the most recent case recorded in West Africa in 2014.

For more than a year since the World Health Organization declared Ebola a public health emergency, new cases in high-risk countries such as Liberia and Sierra Leone appear to be declining.

Image: Ebola virus strain

The virus is transmitted from person to person, through direct contact with body fluids such as blood. Laboratory studies have not recorded airborne transmission of the virus. Typical symptoms of the virus include high fever, headaches, sore throat, muscle aches, vomiting, diarrhoea and rashes on the body. In the advanced stage there is reduced kidney and liver function. These symptoms are also accompanied by bleeding. The above symptoms usually appear about 8-10 days on average after infection with the virus.

After recovery, some side effects have been reported such as joint pain, anorexia, psychological and mood disorders and uveitis (inflammation of the uvea, which carries many blood vessels). This uvea carries nutrients to the retina and improves the contrast of the image we see by reducing the reflected light entering our eye.

How does the Ebola virus affect our eyes and what causes it?;

The eyes are a gateway to the virus, as are the nose, mouth and open skin wounds. As mentioned above, bleeding is a characteristic feature of the virus. The bleeding can be internal (in veins, skin haematomas), but can also occur in the white part of the eye (sclera).

Evidence of the virus has also been found in tears, but also in the aqueous fluid that flows in the front of the eye. The aqueous humour, if not circulating properly, causes an increase in intraocular pressure. Studies have shown that this complication is directly linked to uveitis.

Research has shown that even after several months of survival of Ebola patients, complications - vision problems and inflammation within the eye - can still occur. Among these it is worth mentioning that a 40% proportion of patients who survive the virus have black spots in their visual field (scotomas), blurred vision, pain within the eyeball and inflammation such as uveitis and scleritis (inflammation of the sclera). The researchers in this study report that these complications can occur as late as 9 months after recovery.

What are the symptoms of Ebola in our eyes?;

Ocular symptoms of the virus may include common conjunctivitis, and in advanced stages severe bleeding in the conjunctiva (mucous membrane covering the sclera) may occur. Extreme effects of the virus on the eyes include choroidal haemorrhages which can potentially even lead to blindness.

An interesting study in monkeys showed that a few days after an Ebola virus infection, swelling (swelling) of the eyelids appeared. General elements of the virus can also be found around the optic nerve, causing alterations in the patients' mainly peripheral vision.

Other symptoms that appear in the eyes are loss of vision, photosensitivity and severe tearing.

As we have seen there are many symptoms and complications that the Ebola virus can cause in our eyes. What is striking is that the effects of the virus can linger long after the patient has recovered. We are awaiting further studies to determine the clinical features of uveitis (as the most commonly reported complication), as it is a priority for ophthalmologists. Similar findings apply not only to virus survivors but also to all carriers.

In any case of suspected viral infection, the patient should be immediately supported by appropriate treatment and the competent healthcare authority should be notified so that the necessary steps can be taken to prevent further spread of the virus.