“There has been emerging data during the past year indicating coagulation dysfunction predisposing patients with COVID-19 to both arterial and venous thrombotic events,” explains Avni P. Finn, MD.

A previous meta-analysis of 425 studies showed an overall rate of venous thromboembolism in 21% of patients with COVID-19 infection, a rate that was even higher in patients in the ICU, Dr. Finn notes. “COVID-19-associated coagulopathy is believed to be linked with three combined sources,” she adds. “Activation of the fibrinolytic pathway, cytokine storm or release of prothrombotic inflammatory mediators, and  endothelial damage leading to a pseudo-vasculitis state. Given this, it is plausible that COVID-associated coagulopathy may increase the risk for retinal vascular abnormalities.”

To explore this hypothesis, Dr. Finn. and colleagues conducted a multicenter, retrospective, non-consecutive case series of patients with confirmed COVID-19 infection presenting with hemi-retinal vein occlusion (HRVO) or central RVO (CRVO) between March 2020 and March 2021. “Our inclusion and exclusion criteria were stringent, as we know that vein occlusions most often occur in patients with pre-existing vascular risk factors, so we wanted to exclude these patients,” Dr. Finn says. Also excluded were those older than 50; with hypertension, glaucoma, diabetes, underlying hypercoagulable states, or obesity; and requiring intubation during hospitalization for COVID-19.


Young Patients With COVID-19 & RVO Responded Well to Treatment

The study team examined 12 eyes of 12 patients (median age 32) with CRVO (9/12) or HRVO (3/12) following COVID-19 infection. From COVID-19 diagnosis to ophthalmic symptoms, the median time was 6.9 weeks. The presenting visual acuity (VA) ranged from 20/20 to counting fingers, with VA of ≥20/40 occurring in more than one-half. In 42% of eyes, optical coherence tomography (OCT) revealed macular edema, among which 80% were treated with anti-VEGF injections. At final follow-up, 92% of patients had partial or complete resolution of ocular findings. Retinal thinning, as determined by OCT, was found in 33% by the end of the study interval. The range of final VA measured from 20/20 to 20/60, with 92% of eyes achieving a VA of ≥20/40 at a median final follow-up of 13 weeks.

“We observed that most patients who experienced CRVO after COVID-19 presented for their eye examination within weeks of a positive viral test,” Dr. Finn notes. “These young patients with COVID-19 infection and an RVO responded well to treatment, with the majority of eyes in our study having good visual prognosis with minimal intervention.” She adds that physicians should understand that these patients need not be critically ill to present with retinal manifestations. Patients may benefit from reassurance their condition is likely self-limited and the prognosis favorable with minimal intervention.

“While we acknowledge that a high seroprevalence of COVID-19 exists and that a causal relationship between COVID-19 and CRVO cannot be established, patients and physicians should be aware of this association given the heightened thrombo-inflammatory state caused by COVID-19 infection,” Dr. Finn explains. “In young, healthy patients with CRVO after COVID-19 infection, a possible temporal link exists with ocular symptoms typically occurring within weeks after the viral infection. Therefore, patients with active or recent COVID-19 infection and new visual symptoms should be referred to an ophthalmologist for evaluation of retinal vascular disease. In the future, larger, multicenter, controlled studies are needed to compare retinal vein occlusion rates among young patients with and without recent COVID-19 infection.”