Retinal Vascular Changes in Patients After Coronavirus Disease 2019 (COVID-19)

Retinal Vascular Changes in Patients After Coronavirus Disease 2019 (COVID-19) Based on Retinal Oximetry

The study examines changes in retinal oximetry in patients after COVID-19 disease. It aims to analyze and quantify possible retinal microvascular abnormalities that may result from possible post-inflammatory damage to the endothelium of the vessels associated with COVID-19 disease. Retinal vascular involvement may indicate similar changes in the vascular system in other organs.

The retinal blood vessels are the only blood vessels in the body that can be observed directly. Patients with COVID-19 pneumonia have been shown to have reduced macular vessel density in the foveal region. As a result, some layers of the retina atrophy, reducing oxygen consumption by the retina. Based on this, it is expected that patients after COVID-19 pneumonia, or after a more severe course of the disease, will have normal arterial retinal oxygen saturation but higher venous retinal oxygen saturation and lower arterio-venous difference than patients after mild disease.

Inclusion Criteria:

• age over 18 years
• history of laboratory-confirmed SARS-CoV2-infection
• transparent ocular media allowing for fundus photography
• signed informed consent

Exclusion Criteria:

• known eye disease that has been shown to affect retinal oxygen saturation (diabetic retinopathy, vascular occlusions, use of antiglaucoma drugs)
• any other serious eye disease (advanced or decompensated glaucoma, retinitis pigmentosa, age-related macular degeneration, ocular tumors)
• reduced transparency of the ocular media limiting the visualization of the ocular background and preventing a good quality image from being taken (severe dry eye syndrome, corneal scarring, cataract, significant vitreous haze, vitreous hemorrhage)
• significant refractive error not allowing for sharpening of imaging examinations
• previous intraocular surgery except cataract surgery if performed more than 3 months before the examination
• previous intravitreal application of anti-vascular endothelial growth factor therapy or laser photocoagulation of the retina
• previous severe eye injury
• acute eye infection
• known systemic disease affecting retinal oxygen saturation or causing changes in the ocular background (chronic obstructive pulmonary disease, multiple myeloma, malignant hypertension, hyperglobulinemia)
• pregnancy, breastfeeding