Retinal Imaging Study Diagnoses in COVID-19

A Case Report

José M. Ortiz-Egea; Jorge Ruiz-Medrano; José M. Ruiz-Moreno


J Med Case Reports. 2021;15(15) 

In This Article

Discussion and Conclusions

Back in 2013, Sarraf et al. were the first to describe the presence of multiple or isolated band-shaped, focal or diffuse hyperreflective lesions visible at the level of the internal nuclear layer in patients who presented with acute onset of a negative scotoma, which they called paracentral acute medial maculopathy (PAMM). PAMM is a spectral-domain OCT (SD-OCT) finding interpreted as a possible more superficial variant of acute macular neuroretinopathy.[8]

Its etiology is unknown, although the most commonly supported hypothesis is based on a vascular origin. A localized retinal capillary ischemia at the level of the intermediate plexus has been proposed as the underlying mechanism for the development of these lesions.

As Chen et al. describe, retinal vascular associations leading to retinal vasculopathy and PAMM include eye compression injuries causing global ocular ischemia, sickle cell crisis, Purtscher's retinopathy, inflammatory occlusive retinal vasculitis, pandemic influenza A (H1N1) vaccines reaction, hypertensive retinopathy, migraine disorder and upper respiratory infection.[9] None of these clinical findings was present in our patient.

Early clinical evidence suggests that cases of COVID-19 are frequently characterized by hyperinflammation, renin–angiotensin–aldosterone system imbalance, and a particular form of vasculopathy, thrombotic microangiopathy, and intravascular coagulopathy. There are no conclusive studies in paucisymptomatic or subclinical cases.[10]

To date, there is very limited evidence of the correlation between COVID-19 and the appearance of retinal lesions, presumably because there is wide clinical variation in the presentation and severity of the disease, which may induce the appearance of different morphological patterns of retinal involvement. Marinho et al.,[5] for instance, describe the presence of hyperreflective lesions at the level of ganglion cell and inner plexiform layers more prominently at the papillomacular bundle, but we must be extremely careful with these findings because, as Vavvas et al.[11] point out, OCT hyperreflective bands in the inner retina and/or ganglion cell layer can be confused with normal inner retinal vessels. Landecho et al.[6] recently described cotton wool spots in the retinal fundoscopic examination of the eye and corresponding B-scan OCT showing inflammation of the nerve fiber layer of the retina in 6 of 24 asymptomatic subjects 14 days after discharge from the hospital for treatment for bilateral COVID-19 pneumonia. For this reason, we consider the study with multimodal imaging to be important, agreeing with these authors that we must check at least the near-infrared reflectance record to confirm that the hyperreflective bands do not represent normal vessels (Figures 1 and 2).

Vascular occlusions described in COVID-19 cases might also be the cause of these retinal findings[10] or may be associated with the neurological manifestations described in animal studies and in COVID-19 neurological events.[12–14] It is possible that these vascular occlusions affect the retinal circulation in its superficial and deep plexuses, generating these areas of hyperreflective signals in the inner layers of the retina. Therefore, and exclusively from an ophthalmological point of view, given the possible implications, COVID-19 infection should be excluded by all available means in cases where these hyperreflective lesions occur at the level of ganglion cell and internal plexiform layer OCT imaging without overlying vessels (infrared fundus imaging helps), to facilitate timely diagnosis and intervention.

This case, and the papers presented by other authors,[5,6,11] support the hypothesis that these retinal OCT findings should be considered another sign of COVID-19 disease, hence the importance of retinal imaging study in these patients. Furthermore, to the best of our knowledge, ours is a case of COVID-19 diagnosed through an imaging study of the retina.