Ocular repercussions in COVID-19 patients: structural changes of the retina and choroid

ABSTRACT

Background

Neurotropic capabilities of SARS-COVs allow viruses to reach the central nervous system by hematogenous neuronal dissemination. The human retina, as an extension of the Central Nervous System, may have some neurodegenerative and/or vascular modifications related to COVID-19.

Objectives

To evaluate choroidal and inner neural layers in participants previously recovered from COVID-19 compared to the control group using optical coherence tomography.

Methods

With a cross-sectional approach, the sample (n = 96), constituted by patients who have recovered from COVID-19 (n = 56) and healthy participants control group (n = 40) were ophthalmologically characterized. The neurodegenerative and vascular histological assessment was performed using SD-OCT and the mean thickness was measured in Early Treatment Diabetic Retinopathy Study (ETDRS) subfields. Retinal nerve fiber layer, Ganglion cell layer and subfoveal choroidal thickness were obtained through semi-automatic measurement.

Results

A total of 40 controls (27 women [67.5%]) and 56 COVID-19 participants (34 women [60.8%]) were included in this first report. There were retinal thickness significant differences in nearly all inner ETDRS subfields: nasal 3 mm (p = .025), I3 (p = .049), and temporal 3 mm (p = .009). Also, a decrease in neural layers was found in the nasal 3 mm (p = .049) and temporal 3 mm (p = .029) during ganglion cell layer assessment. The peripapillary retinal nerve fiber layer thickness was thinner in the COVID-19 group in superior temporal (p = .019), nasal (p = .002), inferior temporal (p = .046) and global (p = .014). Concerning the subfoveal choroidal measurement, an increase was observed in the COVID-19 group (p = .002).

Conclusion

Participants who had recovered from COVID-19 showed a non-glaucomatous neuropathy trend pattern. We found differences closer to the classic description of the “bow-tie” observed in other neurological as compressive neuropathies at the chiasma location. OCT assessment also showed an increase in choroidal thickness as a result of vascular changes.

KEYWORDS:

• Choroid
• COVID-19
• ganglion cell layer
• OCT
• retina thickness
• retinal nerve fiber layer

Acknowledgements

Authors acknowledge the support of H&TRC- Health & Technology Research Center, ESTeSL Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa. This project was partially supported by an IDI&CA grant IPL/2020/OCLOVI-19_ESTeSL.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This project was partially supported by an IDI&CA grant [IPL/2020/OCLOVID-19_ESTeSL] by H&TRC- Health & Technology Research Center, ESTeSL- Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa.