Eye changes may indicate long COVID: study

July 28, 2021-“Long COVIDMay be present in the patient Eye, According to a small thing study Published online this week British journal of ophthalmology.

Researchers have found that loss of nerve fibers and an increase in dendritic cells or major immune cells on the cornea may help identify long COVIDs.

Gulfidan Bitirgen, MD and colleagues at the Department of Ophthalmology, Nekmettin Elbakan University Melam Medical School Hospital in Konya, Turkey, found a particularly strong link in a study of 40 patients who lost their patients. Smell sensation Or, after being infected with COVID-19, there was taste or dizziness, numbness, or neuropathic pain.

“The fact that physicians can objectively identify patients with Long COVID makes it possible to identify patients with clear problems and provides a way to assess the effectiveness of treatments that may help with nerve repair. “Opens,” said senior author Rayaz A. Malik, Ph.D., of Weil Cornell Medicine Qatar’s School of Medicine in Doha, Qatar.

At least 1 in 10 people infected with COVID develop long-term COVID. This is what the researchers in this paper have defined as having symptoms that last more than four weeks after the acute phase has passed. Symptoms cannot be easily explained by another diagnosis.

Previous researchers have suggested that nerve fiber damage may be involved in the development of long-term COVID.

“No surprise”

Bitirgen’s team investigated that hypothesis using real-time non-invasive high-resolution imaging laser technology known as the Corneal Confocal Microscope (CCM) to look for corneal nerve damage and dendritic cell density. .. These cells play an important role in the response of the primary immune system.

CCM has been used to identify nerve damage and inflammatory changes in other diseases, including diabetic neuropathy. Multiple sclerosis, When Fibromyalgia..

“COVID has affected so many parts of the body, and it’s not surprising that it affects the eyes,” said Ophthalmologists, Corneas, and Cataracts at Mount Sinai’s Ophthalmology and Ophthalmology Clinic in New York. Dr. Angiewen, MD, an assistant professor of refractive surgery, said. York city.

Checking the cornea via CCM may serve as another piece of information to support a long COVID diagnosis in people with lung symptoms, for example, of unknown cause. Neuropathic pain..

“But it seems that we still can’t draw that conclusion from these results,” she says.

“Our technique is not unique to long COVID because it detects nerve fiber damage, and there are many possible causes for this, but we exclude other causes of nerve damage,” said Malik. If so, I’m pretty sure it’s due to Long. COVID.

“I also think CCM is especially useful for patients with long-term COVID symptoms who can reassure them that there is no damage to the corneal nerves and no serious underlying problems.”

When it comes to access to CCM technology, Malik says the equipment will be installed in most large eye centers around the world.

“Since we pioneered this technology in diabetic neuropathy over 20 years ago, interest has grown exponentially and we are using this technology to assess the extent of peripheral neuropathy, including diabetic neuropathy, inflammatory neuropathy, and HIV neuropathy. There are more than 300 centers to use. chemical treatmentMultiple sclerosis, Parkinson’s disease, dementia“He says.

However, Wen states that outside of large academic centers, the equipment is generally not readily available and probably limits its use as a diagnostic tool.

Need more work

Limitations of the study include a small number of participants and a single site range, and the use of questionnaires to define the severity of neurological symptoms rather than more objective measurements.

“Further studies of a larger cohort of patients using additional measurements of neuropathy and CCM are needed,” the author writes.

Participants in the study recovered from COVID-19, which was identified 1 to 6 months ago. They completed a 28-item National Institute for Health and Care Technology Evaluation (NICE) questionnaire to see if they had symptoms that matched their long COVID.

Answers to the questionnaire suggesting long COVID were strongly correlated with corneal nerve injury.

Neurological 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 primary cells Immune system Response by capturing and presenting antigens from invading organisms.

Corneal scans were compared to scans of 30 healthy people who were not infected with COVID-19.

Scans show that patients with neurological symptoms 4 weeks after recovery from acute COVID-19 have more damage and loss of corneal nerve fibers than patients not infected with COVID-19, and dendritic cells Showed that there are many.

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

“As far as we know, this is the first study to report loss and increase in corneal nerves. [dendritic cell] The density of patients who have recovered from COVID-19, especially those who have persistent symptoms consistent with long COVID. “