Nerve damage in cornea could be sign of 'long COVID,' study hints - Livescience.com

Nerve damage and a buildup of immune cells in the cornea may be a sign of "long COVID," a long-term syndrome that emerges in some people after COVID-19 infection, a new study suggests.

But the findings do hint at something scientists already suspected: Some symptoms of long COVID emerge due to peripheral nerve damage, she said.

This constellation of symptoms hints that long COVID may partly arise from damage to nerve cells in the body, said senior author Dr.

Specifically, preliminary evidence suggests that long COVID may involve damage to small nerve fibers — thin wires that branch off of specific nerve cells in the body and relay sensory information about pain, temperature and itchiness, among other sensations to the central nervous system.

Malik and his colleagues study small-fiber nerve loss in people with diabetes and neurodegenerative diseases like multiple sclerosis; they noticed that people with long COVID appear to share similar symptoms with these patients, so they decided to investigate the potential link. .

According to the new study, published Monday (July 26) in the British Journal of Ophthalmology, people who develop neurological symptoms after a COVID-19 infection show significant small-fiber nerve loss in the cornea, compared with COVID-19 survivors without lingering neurological symptoms.

people who've got the neurological symptoms definitely have a reduction" in small-fiber nerves, while the other participants don't, Malik said.

However, the idea does align with existing evidence that most neurological damage from COVID-19 is caused by inflammation, not by the virus infecting nerve cells directly, according to a 2020 commentary in the journal Pain.

"Infection revs up your immune cells to start firing, to fight the enemy, and there's going to be collateral damage," she said.

Oaklander added that she was "excited" about the new study, as it provides evidence of small-fiber nerve damage in long COVID patients.

In their paper, Malik and his colleagues suggest that corneal confocal microscopy could be used as a diagnostic tool to help identify people with long COVID — particularly those with neurological symptoms.

The gold standard for assessing small-fiber nerve damage involves taking a small skin biopsy from a patient's leg and measuring the nerve endings within, she said.

Doctors can screen for symptoms of nerve damage with written surveys and neurological exams, but they currently require a skin biopsy to confirm their diagnoses.

For now, Malik said his group plans to follow up with their initial group of 40 participants, to see how their corneal nerves and long COVID symptoms change through time

Treatments for post-infectious neuropathies do exist, it's just a question of whether they'd work for long COVID patients with post-infectious small-fiber neuropathy, and if so, how they can best be applied, Oaklander said