Thinner Ganglion Cell Layers Observed in Patients With Neurological Symptoms Following COVID-19

Thinner ganglion cell layer thickness (GCLT) may be associated with neurological symptoms following recovery from COVID-19, according to a study published in Clinical Neurology and Neurosurgery.

Researchers collected data from 40 patients (24 women, mean age 35.9±10.8 years) who recovered from COVID-19 (mean 113±62 days following infection) and 40 age and sex matched control individuals (mean age 33.4±7.8 years, 26 women ). They performed comprehensive ophthalmological examinations, optical coherence tomography (OCT), and neurological examinations on all participants. The primary outcome measure was GCLT thickness in individuals recovering from COVID-19 compared with control group participants. Researchers also sought a correlation between GCLT and COVID-19-related neurologic symptoms. The team excluded individuals with previously documented retinal disease, glaucoma, and high refractive disorder.

The investigators determined that patients recovering from COVID-19 did not have significant differences in GCLT compared with the control group (P=.332). However, a subgroup analysis of patients with cognitive symptoms (brain fog) revealed a thinner GCLT for patients with cognitive symptoms compared with patients who did not experience cognitive symptoms (13±3 vs 16±4 µm; P=.002). The team also noted that participants who experienced headaches had a thinner GCLT than those who did not have headaches (14±4 vs 18±5 µm; P=.015). Investigators did not determine any significant correlations between GCLT and age, anosmia, ageusia, sleep disturbances, COVID-19 pneumonia, or smoking status.

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“This study highlights an association between GCLT values ​​measured via OCT and neurological symptoms such as cognitive disturbance (brain fog) and headache in patients who had recovered after non-severe COVID-19 infection,” according to the researchers. “Unlike other cranial nerve involvement (anosmia and ageusia), central neurological symptoms might be linked to retinal viral entry and may warrant higher surveillance.”

Study limitations include a small sample size, exclusive use of the macula for GCLT measurements, and a wide range in duration since recovery among patients.


Taskiran-Sag A, Eroglu E, Ozulken K, et al. Headache and cognitive disturbance correlate with ganglion cell layer thickness in patients who recovered from COVID-19. Clinic Neurol Neurosurg. Published online April 26, 2022. doi:10.1016/j.clineuro.2022.107263

This article originally appeared on Optometry Advisor


General neurology

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