with long COVID, especially those with neurological symptoms, have corneal
small nerve fiber loss and increased dendritic cell (DC) density, according to
a study published online in the British Journal of Ophthalmology.

Bitirgen, M.D., from Necmettin Erbakan University in Konya, Turkey, and
colleagues quantified corneal sub-basal nerve plexus morphology and DC density
in 40 patients who had recovered from COVID-19 and 30 control participants.

participants underwent corneal confocal microscopy to quantify corneal nerve
fiber density (CNFD), corneal nerve branch density (CNBD), corneal nerve fiber
length (CNFL), and total, mature, and immature DC density.

researchers found that compared with controls, patients with neurological symptoms
four weeks after acute COVID-19 had a lower CNFD, CNBD, and CNFL and increased
DC density; patients without neurological symptoms had increased DC density but
comparable corneal nerve parameters.

correlations were seen between the total score on the National Institute for
Health and Care Excellence long COVID questionnaire at four and 12 weeks with

show that patients with long COVID have evidence of small nerve fiber damage
which relates to the severity of long COVID and neuropathic as well as
musculoskeletal symptoms,” the authors report.

confocal microscopy may have clinical utility as a rapid objective ophthalmic
test to evaluate patients with long COVID.”


Bitirgen et al: Corneal confocal microscopy identifies corneal nerve fibre loss
and increased dendritic cells in patients with long COVID;