Case 1: Central retinal artery occlusion as the only initial symptom of COVID-19
This report presents a case of painless vision loss as the initial symptom of COVID-19.
Case report details
A patient in his fifth decade presented for the acute onset of right, painless vision loss 1 day prior. The patient denied a history of any relevant neurological or ophthalmological symptoms. The patient's past medical history was significant for hypertension and tobacco use. A review of symptoms revealed a 23 day history of mild pharyngitis but no fever, cough, changes in smell, taste, confusion or respiratory complaints.
On examination, pulse oximetry was 97% on room air and the patient was afebrile. Vision was hand motions on the right and 20/20 on the left, with an afferent pupillary defect on the right. Funduscopic exam revealed a central retinal artery occlusion (CRAO) on the right with no embolic plaques. On the left, arteriovenous nicking could be seen with a questionable flame hemorrhage and a cotton wool spot. Based on hospital policies, the patient underwent testing for SARS-CoV-2 and was confirmed positive. Computed tomography angiography (CTA) revealed a long segment filling defect involving the mid and distal portions of the right common carotid artery. High resolution CTA images showed decreased flow in the right ophthalmic artery. Flow in the internal carotid artery reconstituted distal to this point via filling from the right posterior communicating artery. No significant calcifications were noted. Abnormal laboratory results included mildly elevated prothrombin time, international normalized ratio, D-dimer fibrinogen, lactate dehydrogenase and C-reactive protein. Upon review of imaging, the patient was started on therapeutic low molecular weight heparin (LMWH) and transferred to the neurocritical care unit. He remained stable with no new symptoms. The patient remained afebrile and his oxygen saturation remained above 95 % on room air throughout his admission. LMWH was continued with a plan for repeat imaging and transition to oral anticoagulant.
Case 2: Bilateral central retinal vein occlusion presents as an initial symptom of COVID-19
This report details a case of bilateral blurring of vision in patient prior to a diagnosis of COVID-19.
Case report details
A 40-year-old man presented with a 3-day history of shortness of breath, cough, fever, right calf pain and bilateral blurring of vision. His medical history included hypertension and morbid obesity. The patient was found to have severe COVID-19 pneumonia on high-resolution CT of the chest, right leg deep venous thrombosis on Doppler ultrasonography, and bilateral central retinal vein occlusions (CRVO) on fundal examination. A bedside ophthalmology exam revealed a visual acuity of 6/9 in the right eye and 6/18 in the left eye. No fundal imaging was available at this stage due to COVID-19 restrictions but indirect fundal examination at the bedside showed bilateral dilated and tortuous veins, widespread cotton wool spots, dot and blot intraretinal hemorrhages and optic disc edema. These findings were more pronounced in the left fundus. Based on the indirect ophthalmoscopy, the diagnosis of bilateral CRVO was made. By the following week, as the patient’s general condition improved, fundal retinal examination of both eyes revealed improvement in retinal findings compared with the initial bedside findings. OCT showed 2 parafoveal hemorrhages in the left eye on which explained why the patient’s vision was worse in that eye. OCT examination of the fundus did not reveal clinically significant macular edema. Because there was also no improvement in the patient’s visual acuity (right eye 6/6, left eye 6/12), clinicians decided to observe him. The clinical diagnosis, based on clinical fundal examination, OCT, symptoms and course of the disease, was bilateral CRVO. The patient had elevated inflammatory markers, including ferritin, lactate dehydrogenase, D-dimer, C-reactive protein and interleukin-6. He was started on full-dose anticoagulation and discharged on rivaroxaban for 3 months. After 2 weeks of therapy, he had fully recovered from his COVID-19 symptoms and had near-normal vision.
Limitations
While the association between thrombosis and COVID-19 is becoming clearer, there are unresolved questions regarding its possible impact on retinal pathophysiology, especially in a population with multiple risk factors that might develop an asymptomatic SARS-CoV-2 infection, and for which routine ophthalmic monitoring has been suspended. It is not possible to assert with absolute certainty the association between retinal vessel occlusion and COVID-19 as the full effects of COVID-19 inflammatory and pro-coagulant state over the retinal vascular system are currently unknown. However, COVID-19 has been described to predispose to thromboembolic disease in both venous and arterial circulation due to excessive inflammation, endothelial dysfunction, platelet activation, stasis, hypoxia, immobilization and disseminated intravascular coagulation.
Clinical significance
These case reports illustrate the need to have a high index of suspicion for COVID-19 in patients presenting with vision loss, scotomas, decreased vision or blurry vision as COVID-19 can cause a hypercoagulable state leading to retinal vascular occlusions. During the pandemic, it is important to screen for COVID-19 in patients presenting with retinal vascular occlusions, as SARS-CoV-2 carriers can initially present with retinal vascular occlusions and carriers can transmit SARS-CoV-2. These case reports also emphasize the need to follow protocols for personal protection of physicians even in patients not diagnosed with COVID-19 who present with symptoms of blurry vision or signs of vessel occlusions, as these patients could have an underlying undiagnosed active COVID-19. The involvement of the ophthalmic microvasculature in COVID-19 may lead to a new whole spectrum of eye diseases as the retinal circulation is an end arterial system, which is of clinical significance because of the potentially vision-threatening nature of retinal vascular disease.
There is growing evidence demonstrating the association between retinal vascular occlusion preceding COVID-19, which has been described in other publications:
The case report describes a 17-year-old female with history of polycystic ovaries who presented with a 2-day history of decreased vision in her right eye.
This study describes a healthy 33-year-old male who presented with a 1-month history of blurred vision in his left eye accompanied by flashes of light.