Research continues to explore the lasting impacts COVID-19 may have on the body, and a new study looking into how the disease affects the eyes of recovered patients suggests the virus may alter the optic nerve and cause changes in the retinal layers even once the infection has resolved. This study did not link such changes to any appreciable impact on vision or eye health, however.

The investigation enrolled 160 subjects, including 90 recovered COVID-19 patients and 70 healthy controls. All participants underwent an eye exam that included optic nerve OCT. Researchers also considered sociodemographic data, medical history and neurological symptoms in the recovered patient group.

In COVID-19 patients, the investigators observed increases in global RNFL thickness (4.3µm), in addition to greater nasal superior (6.9µm) and inferior (10.2µm) peripapillary RNFL thickness.

COVID-19 patients also showed decreases in volume of the macular RNFL (-0.05µm), as well as superior inner (-1.4µm), nasal inner (-1.1µm) and nasal outer (-4.7µm) quadrants.

Individuals who recovered from COVID-19 also presented with increased GCL thickness globally (0.04µm) and in the superior outer (2.1µm), nasal outer (2.5µm) and inferior outer (1.2µm) quadrants.

Also of note: recovered subjects with anosmia and ageusia exhibited an increase in peripapillary RNFL thickness and macular GCL compared with patients without these symptoms.

Burgos-Blasco B, Güemes-Villahoz N, Vidal-Villegas B, et al. Optic nerve and macular optical coherence tomography in recovered COVID-19 patients. Eur J Ophthalmol. March 15, 2021. [Epub ahead of print].