Analysis of microvascular and neurodegenerative complications of mild COVID-19

Area of Science:

• Ophthalmology
• Neurology
• Infectious Diseases

Background:

• COVID-19 (Coronavirus disease 2019) is a global pandemic with potential long-term health consequences.
• Neurological and microvascular complications are increasingly reported in post-COVID-19 patients.
• The impact of mild or asymptomatic SARS-CoV-2 infection on peripheral nerves, particularly in the retina and cornea, requires further investigation.

Purpose of the Study:

• To investigate retinal and corneal neurodegenerative changes after mild or asymptomatic COVID-19.
• To assess retinal microvascular alterations in patients post-SARS-CoV-2 infection.
• To compare these changes with age-matched healthy controls.

Main Methods:

• Recruited 35 patients post-PCR-proven SARS-CoV-2 infection and 28 age-matched controls.
• Utilized swept-source optical coherence tomography (OCT), OCT angiography, and in vivo corneal confocal microscopy.
• Quantified corneal subbasal nerve plexus and analyzed retinal vessel density (superficial and deep capillary plexuses).

Main Results:

• Patients post-COVID-19 exhibited significantly reduced nerve branch density, nerve fiber area, nerve fiber density, nerve fiber length, and total nerve branch density compared to controls.
• A significant difference in the vessel density of the temporal superficial capillary plexus (SCP) was noted between groups.
• No other significant differences in SCP and deep capillary plexus (DCP) vessel density or structural OCT parameters indicating optic neuropathy were found.

Conclusions:

• Mild or asymptomatic SARS-CoV-2 infection may lead to peripheral neurodegenerative changes.
• In vivo corneal confocal microscopy is a valuable tool for monitoring peripheral neuropathy in post-COVID-19 patients.
• OCT angiography and structural OCT did not reveal significant microvascular damage or optic neuropathy in this cohort.