According to a new American study, Covid-19 has potentially permanent consequences, especially on the eyes. The virus would be the cause of a sharp drop in visual acuity in some patients.
Since the arrival of Covid-19, more than 2 years ago, studies to measure the impact of this virus on the organs are multiplying. After the heart, the lungs, the brain, as well as the intestines, it is now the eyes and more precisely, the blood vessels that challenge scientists.
On April 14, the specialist journal Jama Ophthalmology published a study on loss of visual acuity caused by retinal vein occlusion (RVO). The central vein of the eye is then blocked by a blood clot. “Clinicians should consider the potential association between Covid-19 infection and retinal vascular occlusions when evaluating patients after infection,” explains this study.
This study was carried out between January 2020 and May 2021 on no less than 432,515 patients diagnosed with Covid-19, “without a history of retinal vascular occlusion”. The average age of participants was 40.9 years and 53.6% were female.
During this study, the researchers found that the number of people who suffered from retinal vascular occlusion was higher “in the 6 months after infection with Covid-19 compared to the 6 months before infection”. At the earliest, patients started noticing this symptom between 6 to 8 weeks after diagnosis.
How does this infection manifest?
RVO is caused by a slowing of venous circulation within the retina, due to the inability of blood to drain normally out of the eye. This pathology is however not painful, but is characterized by the appearance of haemorrhages at the back of the eye and a loss of vision “more or less important and relatively brutal”, as indicated by the Sorbonne Ophthalmological Center. Usually only one eye is affected.
“The results provide further evidence for the prothrombotic state induced by Covid-19 and indicate that post-infection impacts can last for several weeks,” the study states.