In some patients with severe COVID-19, the inner retina may harbor acute vascular lesions in the form of flame-shaped hemorrhages and "cotton wool" spots, although it is not clear what is causing these findings, according to a small study from Brazil. "Our results suggest that the retina might be affected in patients with COVID-19. However, given the clinical characteristics of the disease, confounding factors are difficult to control," write Dr. Leonardo Amarante Pereira, of Faculdade de Medicina do ABC, in Santo Andre, and colleagues in the British Journal of Ophthalmology. "Further studies with larger samples are necessary to assess this possibility," they add. One confounding factor could be the common use of vasoactive drugs in critically ill patients, Dr. Amarante Pereira told Reuters Health by email. That's because patients under vasoactive support can experience blood pressure fluctuations, and acute blood pressure peaks can lead to retinal hemorrhages and cotton wool spots, he explained. By looking into the patient's retina, Dr. Amarante Pereira continued, the physician can have a good idea of what is happening in the rest of the patient's body. "Since we do not completely understand the pathogenicity of SARS-CoV-2, the dilated-eye examination can give us some clues," he said. When acute inner retinal vasculature lesions are found in these patients, Dr. Amarante Pereira said, "we have to consider that the rest of patient's organs are also suffering from microvascular dysfunction and ischemia. And that needs to be considered when treating and giving support to these patients." The study was performed in May with inpatients at a Sao Paulo-area hospital that is a referral center for treatment of patients with COVID-19. Of the 18 patients in the study, half were male and the median age was 62. Seventeen were admitted to the intensive-care unit (ICU) at some point during their hospital stay, 13 needed invasive mechanical ventilation and seven needed vasoactive pharmacological support. Twelve patients had a previous diagnosis of high blood pressure, and nine had diabetes mellitus. No patients were known to have ocular symptoms. A retina specialist performed dilated-eye examinations in all 18 patients. These exams showed abnormalities in 10 of the 18 patients, the most common findings being flame-shaped hemorrhages in four patients (22.2%) and cotton wool spots in three (16.7%), with one patient having both types of lesion. Retinal sectorial pallor suggestive of acute retinal ischemia was found in one patient. Other findings included peripheral retinal hemorrhages in two patients, retinal pigment epithelium hyperplasia in one, choroidal nevus in one, and macular hemorrhages and hard exudates in one. Because the authors observed chronic alterations like retinal pigment epithelium hypertrophy and choroidal nevus, they point out that the presence of abnormalities on dilated-eye examination in 10 of the 18 patients was "not necessarily related to SARS-CoV-2 infection." They add, however, that the acute lesions to the inner retinal vasculature and retinal sectorial pallor in some cases appeared in the absence of vasoactive pharmacological support, diabetes, or high blood pressure, "suggesting that they might be related to COVID-19 itself." The researchers also noted that SARS-CoV-2 RNA has been found in the retinas of deceased patients with COVID-19, and that other viruses (including HIV, dengue virus and Zika virus) "are known to cause similar retinal injuries." Dr. Raj Maturi, a spokesperson for the American Academy of Ophthalmology, told Reuters Health by email that because vascular occlusive disease is a known risk of COVID-19, "The eye, with a very visible vascular surface (the retina) is thus an excellent place to review such manifestations." The study, he added, "reinforces the systemic nature of COVID in some patients. Many physicians are using anti-coagulation in COVID-affected individuals, and seeing significant ocular occlusive changes confirms the usefulness of continuing anti-coagulation treatment." —Scott Baltic Source
