New data shows that the loss of nerve fibers and an increase in the number of immune cells in the cornea of ​​the eye is associated with persistent complications after COVID-19. A corneal examination can help diagnose people with this problem.

The so-called authors of a new study published in the British Journal of Ophthalmology explain that the prolonged coronavirus is associated with a number of different, potentially dangerous symptoms that persist for more than 4 weeks after the acute phase of the disease. They say the long virus can infect up to one in ten infected people. At the same time, research suggests that damage to small nerve fibers is involved in the development of this condition.

With this in mind, researchers at Weill Cornell Medical College in Qatar looked at the corneas of forty volunteers with the help of corneal microscopy (CCM). The cornea is a transparent organ located on the surface of the eye that covers the pupil and iris, and its main task is to initially focus light.

With the help of CCM, corneal damage associated with diabetes, multiple sclerosis or fibromyalgia has already been diagnosed.

The participating volunteers succumbed to Covid-19. They recovered from his acute phase one to six months prior to the examination. They filled out a questionnaire that allowed them to know if they had ‘Covid debt’.

In 55 percent of patients 4 weeks after recovery from Covid-19, neurological symptoms were present, and 22 weeks after recovery, they affected 45% of patients. participants.

At the same time 55 percent. Volunteers who experienced symptoms of pneumonia, 28 percent. He had pneumonia, but did not require the use of oxygen, 10 percent was hospitalized and given oxygen, and 8 percent. He was admitted to the intensive care unit with pneumonia.

Corneal examinations showed that patients with neurological symptoms present 4 weeks after recovery had damage to the nerve fibers of the surface of the eye and more dendritic cells.

Dendritic cells play a key role in the immune response, trapping antigens and presenting them to other cells.

Those without neurological symptoms had a similar number of fibers to those who did not have the infection, but they had more dendritic cells as well.

The study was observational and showed no cause-and-effect relationship. It also has – its authors admit – weaknesses, such as a relatively small number of volunteers, a lack of long-term monitoring or reliance on questionnaires.

However, the researchers say: “To our knowledge, this is the first study to show nerve loss and an increase in dendritic cells in the corneas of patients who have recovered from Covid-19. This has been particularly true for people with persistent symptoms of prolonged Covid. We have shown that In patients with long-term Covid disease, there was evidence of damage to small nerve fibers, which correlates with the severity of Covid disease and symptoms of the nervous and musculoskeletal system.”

“Confocal corneal microscopy could find clinical application as a rapid and objective ophthalmic test for the evaluation of patients with prolonged COVID-19 disease,” the researchers added.

More information at http://dx.doi.org/10.1136/bjophthalmol-2021-319450 (PAP)

Marek Matakz

mat / beech /