Science & Technology

There are signs of “long COVID”

Credit: CC0 public domain

In a new study, researchers found that loss of nerve fibers and an increase in major immune (dendritic) cells on the surface of the eye (cornea) could be characteristic of “long COVID.”

These changes were particularly pronounced among people with neurological symptoms such as loss of taste and smell after COVID-19 infection, headache, dizziness, numbness, and neuropathic pain.

Long COVIDs are characterized by a series of potentially debilitating symptoms that last for more than 4 weeks after the acute phase of infection has passed, but cannot be explained by alternative diagnosis.

Approximately 1 in 10 people infected with COVID-19 develop long COVID, suggesting that damage to small nerve fibers may underlie the onset.

In this study, researchers used a real-time, non-invasive, high-resolution imaging laser technique called a corneal confocal microscope (CCM for short) to detect nerve damage to the cornea.

The cornea is the transparent part of the eye that covers the pupil, iris, and interior filled with fluid. Its main function is to focus most of the light that enters the eye.

CCM has been used to identify nerve damage and inflammatory changes resulting from diabetic neuropathy, multiple sclerosis, and fibromyalgia (systemic pain).

The team tested 40 people who recovered from a COVID-19 infection confirmed 1 to 6 months ago and completed a questionnaire to see if they had a long COVID.

They found that brain symptoms were present in 22 of 40 (55%) and 13 of 29 (45%) patients at 4 and 12 weeks, respectively.

Participants’ corneas were then scanned using CCM to look for small nerve fiber damage and dendritic cell density.

These cells play an important role in the response of the primary immune system by capturing and presenting antigens from invading organisms. Corneal scans were compared to scans of 30 healthy people who had not experienced COVID-19 infection.

The team found that 11 people (28%) had clinical signs of pneumonia that did not require oxygen therapy. Four (10%) were hospitalized for pneumonia and were receiving oxygen therapy. Three people (8%) with pneumonia were admitted to the intensive care unit.

Patients with brain symptoms 4 weeks after recovery from acute COVID-19 by corneal scan have more damage and loss of corneal nerve fibers and more dendritic cells than patients not infected with COVID-19. It became clear that there were many.

People without brain symptoms had the same number of corneal nerve fibers as those who were not infected with COVID-19, but had a higher number of dendritic cells.

Answers to the questionnaire showing long-term COVID symptoms were strongly correlated with loss of corneal nerve fibers.

This is the first study to report loss and increase in corneal nerves. [dendritic cell] Density of patients who have recovered from COVID-19, especially those who have persistent symptoms consistent with long COVID.

If you are concerned about long COVID, Causes of long COVID-19 symptoms Survey results with New study confirms long-term lung damage after COVID-19..

For more information on long COVID and your health, see a recent study on. Long-term brain dysfunction in COVID-19 survivors: a pandemic in itself? And the result showing that 7 out of 10 COVID-19 patients in the hospital show long-distance symptoms..

This study is published in the British Journal of Ophthalmology. One of the authors of this study is Gulfidan Bitirgen.

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There are signs of “long COVID” There are signs of “long COVID”

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